At the 15th International Symposium and 7th Conference on Lameness in Ruminants held in Kuopio, Finland, 9-13 June 2008, an international group of experts (the International Lameness Committee, ILC) agreed on standard descriptions of 14 claw lesions commonly found in cattle. Subsequently, a dairy claw lesion poster based on the new standard was co-developed by the Committee and Zinpro Performance Minerals. The poster was created in several formats and widely distributed by Zinpro.
The establishment of standardized lesion names and descriptions has significantly improved communication among researchers, veterinarians, hoof trimmers, farmers and others concerned with cattle hoof health. It has also facilitated the development of computerized lesion recording systems such as Hoof Supervisor®.
The present application is based on the pictorial approach used in the Hoof Supervisor® system - the author gratefully acknowledges that innovative application of the Zinpro/ILC claw lesion identification system.
Most of the lesion photographs are from the library of Dr. Paul Greenough, one of the key members of the International Lameness Committee. Likewise, most of the descriptions provided in the Causes, Prevention and Treatment sections are adapted from Dr. Greenough's 2007 book Bovine Laminitis and Lameness: A hands-on approach. Thanks to Paul for his many and significant contributions to bovine hoof health over the past 60+ years.
Select the zone where the lesion is found
Also called: Axial Wall Fissure
Zones Affected: 11, 12
Prevalence: 0.7% of lesions recorded by Canadian hoof trimmers
Examples of Axial Fissure:
Zone Affected: 7
Prevalence: 1.0% of lesions recorded by Canadian hoof trimmers
Examples of Corkscrew Claw:
The cause of corkscrew claw is unknown, however, there is likely to be a genetic component. Bony deposits (exostoses) are found on the outside aspect of the pedal joint. These periarticular exostoses are located where the lateral abaxial ligament of the joint is located in normal animals. It is, therefore, proposed that strain of the ligament could occur in animals with slightly abnormal limb conformation, particularly if it is forced to place its limbs outwards and backwards to accommodate a very large udder. The fact that bulls rarely show this deformity tends to support this hypothesis.
It is also postulated that the presence of the abnormal bone beneath the coronary dermis stimulates the production of horn at a rate that is more rapid than normal. The pedal bone inside a corkscrew claw is narrower than normal lengthwise. This abnormality is probably caused by molding under the pressures created inside the claw by the disorder. The plantar plane of the distal interphalangeal joint is rotated by 11° from normal. This is considered to be the result of the disorder rather than its cause. This hypothesis is supported by the observation that traumatic injuries or surgical interventions involving the coronary band sometimes result in the formation of a false corkscrew.
Once established, a corkscrew claw will require trimming every 3 months if the cow is to remain functionally efficient. Trimming should only be attempted by a skilled trimmer who will remove the exceptionally hard wall from beneath the claw. Often some degree of white line degeneration shows in the form of hemorrhagic horn. Bleeding in this area can be avoided by leaving the tip of the claw thicker than the normal. Sometimes a white line abscess, with total under-running of the sole together with the risk of bone infection, can develop after a routine claw trimming procedure. The condition is irreversible, and affected animals must be culled at the end of a current lactation.
adapted from: Paul R. Greenough, Bovine Laminitis and Lameness: A hands-on approach, Saunders Elsevier 2007
Also called: Hairy Heel Warts, Mortellaro Disease
Zones Affected: 9, 10
Prevalence: 40.0% of lesions recorded by Canadian hoof trimmers
Examples of Digital Dermatitis Lesions:
The infectious form of Digital Dermatitis (DD) was first reported in Italy in 1974, in The Netherlands in 1986, and in the United Kingdom in 1988. A similar condition was reported in North America in 1992.
DD is, by definition, primarily an acute inflammation of the hairy skin (dermatitis). In its very earliest stage it is indistinguishable from interdigital dermatitis. It may spread into the interdigital cleft or undermine the bulb, thus including the modified skin of the claw.
A badly affected animal will be lame and/or may hold its foot from the ground and/or walk on its toes. There is no associated digital swelling or fever as compared with foot rot. Early lesions are characteristically discreet, circular to oval (0.5–1cm diameter), hairless, moist, red or tan, prone to bleed, and very painful plaques with granular or velvet-like surfaces often edged with a halo of white tissue.
There is considerable controversy about the exact cause of this disease. The primary organism consistently isolated from DD lesions is a spirochete bacterium.
Animals may be predisposed to DD by the prolonged exposure of digital skin to oxygen-depleted, wet and organic material containing the causative organism(s). Management conditions that may be involved are poor drainage, accumulation of feces and urine on floors, dirty, wet or uncomfortable bedding areas and overcrowding.
Once the skin has been rendered vulnerable, the superficial layers of the epidermis may be further degraded by bacterial action, making way for the entry of the spirochete. Apparently a synergistic interaction by different bacteria supporting each other is required. This might explain why experiments using spirochetes alone failed to produce lesions even if the skin was damaged by scratching beforehand.
A genetic predisposition might be involved; the properties of the epidermal barrier could be weaker in some animals. Lack of micronutrients, minerals, and vitamins can result in a weaker skin barrier. Disturbances in the local immune system might be involved or mechanical injuries, hyper-hydration of skin epidermis, or hygienic problems may be implicated.
Young animals are particularly susceptible. However, it appears that some degree of immunity may be acquired over time by continued exposure to the infection.
The disease is introduced into a herd by replacement cattle, human beings or vehicles. Unsterilized equipment used in hoof trimming could be an important source of the disease.
DD is confined to the skin between the heel bulbs and the dew claws. Foot rot starts as an interdigital disease with swelling eventually affecting the whole digital region and the animal having a raised body temperature. While systemic administration of antibiotic is usually effective in treating foot rot, DD is unresponsive to such treatment.
ID is primarily a disease of the superficial layers of the epidermis of interdigital space. However, infection can encroach on the skin of dorsal and flexor commissures of the interdigital space. Although ID can be confused with the early stages of DD, the latter condition is more aggressive and rapidly affects numerous animals with typical lesions.
Each of the four feet must be examined, and each lesion, particularly if papillomatous, scrubbed using soapy water and a very stiff brush. The lesion should be dried. Applying an agent to a filthy or debris-encrusted lesion will have no effect at all. Applying an agent to a wet lesion will dilute the effectiveness of the medication.
The topical dressing must be protected by a pad of gauze held in place by an adhesive bandage. Waterproof bandages are problematic because most of them will create anaerobic conditions which are ideal for the bacteria to grow. It is recommended that less severe lesions should be left open after cleaning. Topical treatment with tetracycline spray on two or three occasions is usually sufficient.
Larger and deeper lesions should be covered for reasons of protection but also to prevent spreading of bacteria. A reusable device such as a ‘Bootie’ (Mountain Meadows, Providence, Utah 84332, USA) can be extremely useful. A small sanitary napkin has been found to be useful in keeping medication in place beneath a bootie or bandage.
One treatment may be effective for relatively mild infections, but repeated applications may be called for in more extensive lesions. External treatment has not been shown to produce antibiotic levels in the milk.
All advanced lesions must be given topical treatment as described above. However, the heels of the remainder of the herd should be washed with a low-pressure hose until the details of any lesion that may be present can be clearly seen. Topical treatment should be applied using a 500mL spray bottle or a garden-type spray. Under free-stall conditions, the treatments can be carried out with the animals fastened in automatic headlocks. This treatment should be continued for 3 weeks, using either antibiotic or non-antibiotic preparations.Oxytetracycline has proved significantly more effective than the last two chemicals in this list:
A 10% solution of formalin may also be used alternately with an antibiotic, but extreme care must be taken to avoid spraying this chemical on the udder or other areas of healthy skin.
Foot baths have been used extensively to treat and/or control DD. The use of this technique has tended to decline in North America in favour of topical treatment. Foot baths are difficult to use and some medications such as formalin are less effective as the temperature drops. However, the main reason for veterinary surgeons not recommending this technique as frequently as they used to is that many farmers mismanage the procedure. That is to say, the baths are not cleansed with sufficient frequency. There is also concern that disposal of the solutions into the environment will cause pollution.Common antibiotic footbath solutions (per 200 litres of water) consist of:
The use of copper sulfate, zinc sulfate, or formalin in foot baths has given inconclusive results when used alone. However, these foot baths may have a beneficial effect if used between antibiotic treatments. The medications would reduce the prevalence of interdigital dermatitis and thus, perhaps, decrease the susceptibility for digital dermatitis.
Antimicrobial resistance to antibiotics such as oxytetracycline is starting to be reported; therefore, the type of antibiotic used should be changed every 6 months. Antibiotics in foot baths are prohibited or not recommended in Europe.
Spirochetal vaccines have been developed and are effective in controlling certain diseases in animals and man. Furthermore, humoral antibodies against spirochetes have been found in cows affected with DD and no antibodies in cows without DD. This indicates that the organisms do cause an immune response in affected cows. This encourages the concept that vaccination against DD will sooner or later become possible. Scientifically controlled trials have not established that any commercially available vaccine gives satisfactory results.
Good hygiene is the single most important factor in controlling DD. Slurry removal at short intervals is essential and good drainage of alleyways should be implemented. Excessive floor washing should be avoided if rapid run off is not taking place. In herds where this condition is not yet a problem, it is recommended that if replacement cattle are to be allowed into the herd they should be isolated for one month, and then carefully examined before they are introduced to the rest of the herd.
adapted from: Paul R. Greenough, Bovine Laminitis and Lameness: A hands-on approach, Saunders Elsevier 2007
Also called: Foul, Phlegmon, Interdigital Phlegmon, Interdigital Necrobacillosis
Zone Affected: 9
Prevalence: 1.9% of lesions recorded by Canadian hoof trimmers
Examples of Foot Rot:
The overall incidence of foot rot is probably less than 5%, but in epidemic outbreaks the incidence of the disease can be as high as 20% of the milking cows in a herd. Foot rot is an extremely painful condition. Pain causes a negative physiological reaction as well as reducing the animal’s incentive to seek feed and water.The following clinical signs are routinely present:
The mean yield from a high-production cow affected with foot rot can be as much as 1,285kg less than that of a healthy cow. This is particularly noticeable if a milking cow has foot rot before she reaches her milking peak and treatment is delayed. In this case, the total yield for the lactation may drop by more than 20%. If the disease occurs toward the end of the lactation or when the cow is dry, the economic loss will be less severe. In countries where antibiotics are available to producers, the cost of medication has to be considered. In countries that require treatment by a veterinary surgeon, the costs will be much higher. An added expense is loss of milk sales resulting from the withdrawal time required for some medications.
There will be temporary reproductive problems such as delayed heat and/or poor conception.
A very acute form of foot rot has been described in Europe. ‘Blind foul’ is a form of the disease causing considerable swelling but no interdigital lesion during the early stages. It is believed that this condition may be caused by blood-borne organisms. ‘Super foul’ is the form of the disease that is extremely aggressive and fails to respond to treatment. Radiography is not useful in most instances, but is essential in cases failing to respond to treatment, and when either septic pedal arthritis or a retroarticular abscess are suspected.
Fusobacterium necrophorum has been isolated from over 90% of clinical cases of foot rot in cattle. Strains of F. necrophorum are normal inhabitants of the intestine of cattle and are, therefore, shed into the environment but their pathogenicity is uncertain. The organism can remain dormant in the soil for several months, particularly in the presence of dried feces. It contaminates areas where cattle congregate, such as tracks, areas around drinking sources, in gateways, in muddy corrals, or in the slurry of barns and loose houses.
It is believed that most cases of foot rot result from the organisms entering the subcutaneous tissue through interdigital skin. It has been assumed that this occurs as the result of traumatic damage or the action of irritant agents in slurry. Another commonly held opinion is that the skin is made vulnerable by the action of various organisms frequently found on the skin of the digit. Whatever the cause, the protective barrier of skin must be weakened or damaged before the bacteria can invade the underlying tissue.
A genetic predisposition might be involved; the barrier can be less strong in some animals. Lack of micronutrients (minerals, vitamins) can result in a weaker skin barrier. Disturbances in the local immune system might be involved, as might mechanical injuries, hyper hydration of skin, or simply poor hygiene.
Delay in treatment not only increases the loss of milk but also the loss of body condition. If treated, most cases respond very rapidly, usually with very little after-effect. Although immediately after recovery there is a very strong immunity, recurrence occurs occasionally if the animal encounters other strains of the organism. Natural immunity appears to inhibit re-infection by the same strain for at least 6 months. If a new case of foot rot occurs in a cow within 6 months of an original infection the diagnosis should be carefully re-examined.
If foot rot is not treated, the course of the disease will be prolonged and the risk of complications will increase. Nevertheless, in some feedlots in the United States, it has been found that treatment is not cost effective. The rationale for this practice is that sorting beef steers to identify lame animals is far too labor intensive. Feedlot operators find that the steers recover spontaneously after suffering a set-back in weight gain, but that compensatory growth minimizes the economic loss.
Conventional treatment has been, for many years, the intramuscular injection of penicillin G for three consecutive days. However, in recent years, penicillin has been proving less effective and much higher doses than recommended on the product label have to be used. If the dose is increased, so must be the withdrawal times for the milk.If cows fail to respond to treatment with an antibiotic within 48 hours, there are three different reasons that could account for this:
Successful treatment has as much to do with case management and pharmacokinetics in the affected tissue as it does with bacterial susceptibility. Delayed diagnosis and treatment, inadequate cleaning of the lesion, poor treatment schedules, or selection of an inappropriate drug all contribute to a lack of success.
Unresponsive cases should be given a broad-spectrum antibiotic such as long-acting oxytetracycline. Tylosin, or sodium sulfadimidine, trimethoprim sulfate, amoxicillin, ampicillin, cephaloridine, gentamicin, clindamycin, and streptomycin have all been used with satisfactory results. It is best for a producer to discuss the treatment strategy with a veterinarian.
The most effective way to treat the most advanced, unresponsive, and/or acute cases is by intravenous infusion via the digital vein with a suitable antibiotic. This procedure must be undertaken by a veterinarian. A tourniquet is applied above the swollen region and the injection is made into one of the veins. (If the limb is very swollen it is often difficult to find the vein.) The tourniquet can be left in place for 20 minutes. If the tourniquet is applied for a longer period, tissue damage will occur. The tourniquet is released slowly to ensure that the antibiotic does not flood into the body at too rapid a rate.
If the skin of the interdigital space has sloughed, topical treatment is essential. This is particularly important if a secondary lesion appears to be starting in the dorsal region of the interdigital space, at which point the capsule of the pedal bone is very superficial. The wound should first be cleansed with soapy water, then thoroughly dried. A generous amount of a topical dressing such as an antibiotic paste should be applied and held in place with a light pad of gauze. The lesion must then be protected at least for a few days. It is poor practice to wrap a bandage between the claws as this opens the wound and delays healing. However, the claws may be bound together with a bandage. In order to avoid the bandage acting as a wick when immersed in slurry it may be enveloped in a stout freezer bag and protected from wear with duct tape.
If appropriate treatment fails to produce an early resolution, the case should be re-checked for complications or an alternate diagnosis.
Some reduction in incidence may be expected if regular foot bathing is practiced. Indirectly the foot bath can reduce the risk for foot rot by reducing interdigital dermatitis. Footbaths using 5% copper sulfate are useful, but this chemical deteriorates rapidly in the presence of the organic material in manure; therefore, a cleansing system (water bath) preceding the chemical bath is advocated. Formalin, used at 2–4%, is useful, but the fumes can be undesirable in the milking parlor.
Newer solutions and foam products are coming on the market which are claimed to be superior to either formalin or copper sulfate, however, the documentation of the effectiveness is poor.
The value of zinc methionine is strongly supported by research findings. Anecdotally, testimony to the effectiveness of the product can be taken from the high percentage of feedlots in the United States using the product. Cattlemen rarely invest in practices which are not cost effective.
The use of oral inorganic iodides is prohibited in some countries. Where it has been used commercially, the benefits are considered to be variable.
Paraformaldehyde is a polymer of formaldehyde but is degraded at a slower rate than the simple chemical, so it persists in the environment for a lengthier period of time. The addition of 25–50lbs (55–110kg) of paraformaldehyde per feedlot pen has been shown to temporarily suppress bacterial proliferation and significantly reduced the incidence of foot rot.
Natural immunity of heifers could be strengthened by exposing them to dry herd mates in good time before calving. Proprietary vaccines are available but are, at present, questionable as to their cost effectiveness. Two injections are required one month apart, but the immunity that develops only reduces the incidence of the disease slightly and does not eliminate the risk completely. The use of autogenous vaccines (custom vaccines prepared from samples from actual lesions) has proved to be very effective with deer.
Nevertheless, vaccinating bulls semi-annually is strongly recommended. When a bull suffers from foot rot, the fertility of the animal drops immediately and is slow to recover. Bulls will also be at higher risk if transferred between herds that are affected by slightly different strains of the organism.
Once a case has become ‘open,’ the discharge of the causal organisms into the environment causes contamination of those areas in which the traffic of cattle is heaviest. Therefore, reducing exposure to slurry will be the first consideration. Good drainage around drinking and feeding areas is essential. The isolation of affected cows by moving them to a separate pen or stall (or the use of a protective boot) during the early infectious stages of the disease is strongly recommended. Very early, adequate treatment is essential. When herds are expanding and animals are bought in, special care must be taken. Older cows may introduce new strains of the organism, while heifers may have no immunity at all.
adapted from: Paul R. Greenough, Bovine Laminitis and Lameness: A hands-on approach, Saunders Elsevier 2007
Also called: Heel Horn Erosion, Slurry Heel
Zone Affected: 6
Prevalence: 1.0% of lesions recorded by Canadian hoof trimmers but probably is not routinely recorded due to its very common occurence.
Examples of Heel Erosion:
Heel erosion was only given international recognition in 1976. Prior to this date, it was given a variety of colloquial names such as ‘stable foot rot’ and ‘stinky foot’. Very few descriptions of the disease appear in the literature. It has been found that at least 50% of a herd can be affected with erosion of the heel.
Heel horn erosion is usually more extensive the older the animal becomes. It commences between the cheeks of the heel bulbs. In young animals, it may appear as discrete craters which coalesce over time. Gradually, the lesion involves a greater area of the claw capsule. The lesions rapidly become darker in color, typically form a series of ridges, and often end as a dark V-shaped erosion. The discolored horn is much softer than normal horn.
Uncomplicated cases cause the animal very little discomfort. However, after a time, as more heel horn is destroyed, the longitudinal balance of the claw is disrupted. If weight-bearing is moved forward as a result of this process, the formation of a sole ulcer can be precipitated.
In extreme instances, the build-up of heel horn can be so extreme that the pressure causes an inflammatory reaction to pressure in the corium of the heel. An alternative explanation is that pain caused by the hard edge of the skin/horn junction decreases wear of the heel horn which grows faster than it wears. Overburdening often causes the posture to become ‘cow hocked.’ Correct trimming will correct this posture.
Although heel horn erosion was described over 30 years ago, little progress has been made in understanding its cause. The effect of slurry and invasion by bacteria has been proposed, and the presence of Dichelobacter (Bacteroides) nodosus has been demonstrated with direct immunofluorescence in the germinal cell layers. The late Egbert Toussiant-Raven believed the condition to be encountered more commonly in animals affected with subclinical laminitis.
Even though there is a very high incidence of this disorder, only very few cases cause an animal any significant degree of discomfort. On the other hand, it has been found routinely that Holsteins, with an average production of 9,800 kg of milk/year and with otherwise sound feet, increased their daily average milk production by 2 kg subsequent to the control of heel horn erosions. If gross lesions are corrected during claw trimming, the effectiveness of foot bathing will be improved by allowing medicated solution to reach the otherwise sealed depth of the heel horn erosion.
Another negative effect of the interdigital dermatitis / heel horn erosion complex is that horn production is stimulated, making it necessary for routine claw trimming to be performed more frequently.
If erosion is extensive, the weight-bearing zone of the heel/sole junction will move forward, causing traumatic reaction in the corium. This complication does cause the affected animal to become lame. The horn should be trimmed in such a manner that there is a slope towards the abaxial wall. Most hoof trimmers will spray the cut surface of the trimmed horn with a preparation containing copper sulfate or apply Stockholm tar.
As Digital Dermatitis and/or Interdigital Dermatitis are often associated with the heel erosion, the primary disease must be treated to have a long-term improvement. Horn erosions will resolve provided that new lesions do not appear.
Routine claw trimming will prevent the development of advanced lesions. Regular foot bathing during the winter months reduces the severity of heel erosion. Copper sulfate (5% solutions) and formalin (1–5%) have been found to provide satisfactory results.
Also called: Hardship Groove, Horizontal Wall Fissure, Fissura Ungulae Transversalis
Zones Affected: 7, 8
Prevalence: 0.2% of lesions recorded by Canadian hoof trimmers
Examples of Horizontal Fissure:
The term ‘horizontal fissure’ is used loosely to describe a variety of different appearances in the horn of the wall running parallel to the hair line. Grooves and fissures affect beef and dairy cows alike. If more than 20% of the cows in a herd have grooves, at approximately the same distance from the hair line, on more than four claws, it is certain that a short-term stress or nutritional problem has occurred. The deformities associated with grooves are unsightly and affect the saleability of pure-bred beef cattle. Grooves and fissures may play a part in causing sandcracks.
Beef calves are weaned at the end of the summer. The change in diet from dam’s milk to grass is dramatic. Often, at this time, the calves are dehorned, castrated, vaccinated, transported, and spend time in a market. When the animal finally reaches the feedlot the composition of the ration consists of concentrate and forage, the opportunity to exercise is considerably reduced, and the little animal is subjected to confrontation by other animals. Some animals adapt more readily to these changes than others and the evidence can be seen in the claws.
Dairy heifers are not subjected to such extreme stresses or changes in management. There should be no such abnormalities in the claws of a dairy heifer between 20 and 26 months of age. When this is found not to be the case there is likely to have been some serious error in the earlier management of the animal.
Groove, fissure, thimble, and broken toe describe the appearance of a lesion at different stages and/or of different severity.
A hardship groove is a depression running around the wall of a cow’s claw more-or-less parallel to the hairline. For example, it is not unusual for such a groove to be produced as the result of a hard calving. The hardship groove is nothing more than an indication that the animal was subjected to a short-term stress which could be an acute febrile illness. The date when stress occurred can be determined by measuring its distance from the hair line to the groove.
The deeper the groove the more severe the insult. Sometimes a ‘fissure’ will penetrate right through the wall and as it grows closer to the bearing surface it remains attached only by sensitive tissues. A fissure causes considerable discomfort and reduce the animal’s willingness to walk and forage for feed. This may affect productivity. As the fissure grows towards the apex of the claw it is referred to a ‘thimble.’ When the thimble breaks off, the end of the toe which is left is square. If a herd of cows has a high population of animals with square toes it can be assumed that a problem has been ongoing for many months.
A horizontal groove or any other of its various forms is caused by an interference with claw wall horn production. This short-term disruption in horn production can vary in degrees of severity. To complicate this issue, there is considerable variation between animals in the degree to which they can adapt to the cause of the disruption. The mechanical strength of the claw capsule is influenced by changes in its shape and the degree to which the dorsal wall increases in concavity around hardship grooves. Neglected, overgrown claws (as they increase in length) will experience increases in pressure beneath the toe and this results in greater tension on the ‘instep.’
With the exception of thimbles, treatment is inappropriate. Thimbles are extremely painful, therefore, animals react violently when they are removed. If this procedure is attempted, the animal should first be sedated. With dairy cows, the foot to be treated should be placed on a piece of wood about 12 inches square. Lifting the other limb will fix the limb to be treated. The cutting edge of a woodworker’s chisel is then inserted into the crack in such a manner that the shaft runs almost parallel to the dorsal wall of the claw. The beveled edge of the blade should face inwards. A quick strike with a hammer will remove the offending horn. Alternatively, the tip of the claw (thimble) can also be removed with hoof cutters when the limb is elevated. This technique is less precise and evokes a very violent reaction on the part of the patient.
Unless about 25% of the animals in a herd have grooves or other manifestations related to grooves in one or more claws, control measures are probably not called for. However, if over 25% of a herd has grooves in roughly the same position, then the timing of the insult should be identified. Once the date of the insult has been calculated, the investigator should identify the managerial or nutritional change occurring during the appropriate time frame.
Also called: Stable Foot Rot, Scald
Zones Affected: 0, 10
Prevalence: 4.4% of lesions recorded by Canadian hoof trimmers but some cases may actually be Digital Dermatitis.
Examples of Interdigital Dermatitis Lesions:
This condition has been confused in the literature with foot rot. The clinical signs of the two diseases are, however, distinctly different. ID causes no inflammation nor edema of the digital region as is the case with foot rot. The body temperature does not rise, milk yield does not drop until complications are present, there is no sloughing of necrotic material from between the claws, nor is an animal lame in the early stages.
ID in cattle is caused by Dichelobacter (Bacteroides) nodosus. However, different genotypes of this same organism cause foot rot in sheep. Transmission of the severe disease in sheep to cattle has not been reported.
The importance of ID is the probability that it may play a (yet unproven) role in the evolution of other diseases such as foot rot, digital dermatitis, and heel erosion. D. nodosus and F. necrophorum have been consistently isolated from many foot lesions. However, other organisms frequently present in the interdigital space could also play a part in the progress of some of these diseases.
As the condition progresses, the animal shows discomfort by constantly moving from one foot to the other – this is an obvious sign of irritation or itching. The limbs may be held further back than normal.
True lameness may not occur until a complicating lesion is present. ID is strongly related to heel horn erosion as a secondary complication and this may be the most important complication of the disease. There is a low prevalence of ID in cattle at pasture, but it will increase when animals are confined and housed.
ID is particularly prevalent when the feet of cattle are continuously bathed in slurry. This state of affairs occurs most commonly during cold winter months. By later winter, some animals may be showing discomfort and pain-producing lesions may be observed.
In cases of ID, erosion of the heel horn will reduce the height of the heel. Less frequently, after a prolonged period during which the animal has avoided bearing weight on the heel, the horn beneath the heel will increase in thickness, causing some aberrations of gait.
The use of systemic therapy including antibiotics is not warranted. In severe cases, the lesions should be cleaned and dried, after which a topical bacteriostatic agent should be applied, e.g., 50% mixture of sulfamezathine powder and anhydrous copper sulfate. Oxytetracycline sprayed onto a cleansed lesion is also effective. Alternatively, an animal can be confined in a 5% copper sulfate foot bath for one hour, twice daily for three days.
At the present time, vaccines are not available for cattle.
Interdigital dermatitis is most severe in the presence of unhygienic conditions which are likely to occur in most operations during the winter months. Control measures must include reducing the presence of slurry and favour dry underfoot conditions. Regular foot trimming will help to avoid complications by early detection and treatment.
Foot bathing, commencing in late fall and before clinical cases can be identified, is essential in herds known to be infected. Solutions of 3% formalin or 5% copper sulfate are usually effective. However, these chemicals biodegrade slowly; therefore, new products are being presented in the market. Weekly foot bathing may be sufficient in the late fall, but the frequency may have to be increased in late winter.
Also called: Corn, Interdigital Fibroma, Interdigital Growth
Zone Affected: 0
Prevalence: 4.4% of lesions recorded by Canadian hoof trimmers
Examples of Interdigital Dermatitis Lesions:
Interdigital hyperplasia results in a fold of fibrous tissue hanging down into the interdigital space. Sometimes these abnormalities are so long that they rub on the ground and the skin is eroded away.
There is a hereditary component to the condition which determines the transmission as an inconsistent autosomal dominant pattern. The male progeny of a bull with a fibroma are more likely to be affected than would be normally expected. The higher the butterfat yield of the dam, the higher the risk for a fibroma in male descendants. The heavier the weight of a Holstein-Friesian bull, the greater the frequency of interdigital fibromas.
The hyperplasia is caused by over-tension and slow fibrosis of the subcutis of the interdigital skin. Poor conformation such as splayed digits may be a contributory cause. Inflammation of the skin resulting from interdigital dermatitis (ID) or digital dermatitis (DD) may cause some hygromas. Poor footing (slippery slatted concrete) can also be an important contributor to the condition by splaying the digits. Also, combinations between these factors are seen when ID is a herd problem.
In simple cases or in those in which lameness is not a factor, treatment of the ID, DD or sole ulcer together with a change of the causing environment may be sufficient to allow spontaneous healing. In more advanced cases surgery is required. However, if the conformation of the foot is poor or if the causative environmental factors are not eliminated there is a high risk for reoccurrence.
Control of ID and DD in dairy herds will reduce the occurrence of this condition. The slipperiness and unevenness of floors should be corrected, as well as unstable concrete on slatted floors or slats that are too wide.
Also called: Sole Bruising
Zones Affected: 4, 5, 6
Prevalence: 10.2% of lesions recorded by Canadian hoof trimmers
Examples of Sole Hemorrhage:
A sole hemorrhage may be due to a bruise or to subclinical laminitis. In practice, it is very difficult to identify the difference between the two because there is a great deal of overlap between their clinical signs.The clinical signs of bruising are:
In other words, bruising can occur solely as the result of trauma. If the disorder goes unrecognized, the sole will gradually disintegrate and lameness will become more pronounced. In rare instances, if the corium itself is severely damaged the horn repair will be very complicated under field conditions.
Hemorrhages in the sole are exposed when overloaded claws are trimmed. Hemorrhages are very commonly seen in the claws of first-calving heifers, particularly after the animals may have experienced a dramatic change in diet at the same time they were moved from a soft footing to concrete. Therefore, the history should also be taken into consideration as well as the appearance of the lesion.
It is impossible to be dogmatic about the typical appearance of a sole of an animal affected with subclinical laminitis (SCL). The sole of a claw may have a yellow tinge which may be due to the escape of serum. A similar yellowish tinge is caused by staining from manure. However, in a trimmed claw staining by manure will not be present. In other words yellow coloration of recently trimmed sole horn will be a clinical sign of SCL. The hemorrhage typical of SCL tends to be diffuse and some will show the characteristic ‘brush mark.’ It is likely that more than one claw would be affected, and within a group of animals several would have claws very similar in appearance.
Animals with SCL do not appear lame as is the case with bruising. However, they have a characteristic gait; they walk carefully, they are said to look as if they are ‘walking on eggs.’ Not every animal will be at the same stage of lactation when examined; therefore, feed intake will vary and this affects the rate of horn production and quality. This means that not every animal will be subjected to the same stress and their claws will appear different one from the other.
Most cases of bruising result from prolonged walking over rough roadways or tracks. Lumps of ice in dirt lots can cause similar damage. Stress from social confrontation in herds confined on hard, abrasive floors can cause low ranked animals to be chased around. Animals in estrus could cause over wear of the bearing wall and sole.
Care must be taken after claw trimming that cattle are not forced to walk even for short distances on hard, rough surfaces. Claw trimming exposes soft, temporarily vulnerable soft horn after old, dry, and tough layers of horn are removed. In the first days after a trimming session, during the cold season, some degree of accelerated wear of the claw will take place and this has to be taken into account by leaving those claws a little longer (1/8 inch or 0.3–0.5 mm). Over-trimming itself, often the use of a grinder in inexperienced hands – and especially in combination with subsequent exposure to rough concrete or asphalt alleys – can cause severe damage to individuals or a group of animals.
The resolution of a bruise and/or complications following a bruise depends on the animal’s ability to grow a new sole. Pressure stimulates horn production; therefore, most cases will respond spontaneously if the animal can be confined entirely to an area very deeply bedded with straw, on rubber mats, or exposed to grass or sand. However, if the sole of a claw has been fragmented, protection must be provided and the patient must be prevented from walking. The best treatment is to use a shoe, such as a ‘Shoof,’ on all affected feet. Alternatively a ‘lift’ can be applied if one of the claws is unaffected. Bandages are best avoided as the fabric acts as a wick drawing moisture to the sole, preventing it from hardening. However, bandages impregnated with Stockholm tar may have a beneficial effect in stimulating the growth of healthy sole horn.
Claw trimmers must warn clients of the dangers involved in forcing the cattle to walk on hard surfaces, such as rough concrete or graveled pathways, for some days after trimming – particularly in wet weather. As the moisture content of the claw horn increases, so it will become softer and vulnerable to wear. Also with animals housed on newly constructed concrete floors, it could be detrimental to trim the claws as severely as usual. Trimmers must, in these cases, reduce trimming to a minimum and avoid excessive reduction of the bearing surface of the wall, but at the same time leaving just enough to achieve a good balance of weight distribution.
Claw trimmers should also be aware that the minimum dimensions of the claw capsule after trimming are not an absolute goal. Trimming must be made according to the environment where the cow lives. If the cows are forced to live on concrete, the thickness of the sole is like money; you can never have enough of it. Trimming in this case is aimed at restoring the correct angle between the dorsal surface and the bearing surface (~45°) and at preserving the highest possible bulb.
When cattle habitually walk for long distances, the use of rubberized roll matting has proved to be invaluable. These mats measure about one meter in width. Cattle can be seen walking along, single file, on these strips of fabric.
Also called: Pododermatitis Circumscripta, Rusterholz Disease
Zone Affected: 4
Prevalence: 15.7% of lesions recorded by Canadian hoof trimmers
Examples of Sole Ulcer Lesions:
With this disorder, the progress and severity of lameness are variable. When both lateral hind claws are affected, lameness is not easily detected, as pain in one foot tends to balance the pain in the other.
In tie stalls, the hind toes may be rested on the edge of the curb of the stall in an attempt to relieve pain. On flat surfaces, an affected animal will stand with the hindlimbs camped back. Some cows may shake the affected foot frequently. When both hind feet are affected, the cow may continually shift weight from limb to limb and frequently lie down.
A sole ulcer can be concealed below a layer of horn which may be discolored.
Clinically, it is possible to distinguish between an open and closed ulcer. If the cow does not react to pressure on the discolored area of the sole, the lesion should be considered closed; in other words, it has not reached a point at which preventive treatment is likely to be unsuccessful. If the lesion responds to pressure, it should be considered as being open and loose horn will have to be removed.
A sole ulcer is caused by pressure which crushes and destroys horn-producing tissues between the flexor process of the pedal bone and the inside of the sole. Horn production then ceases over a very small ‘circumscribed’ area. This, in turn, causes a hole to develop in the sole through which granulation tissue (proud flesh) will protrude.
Subclinical laminitis (SCL) is associated with the production of softer-than-normal horn. When this happens, the sole of the claw wears more rapidly than normal. Consequently, the sole is thinner and flatter than normal, making the ‘typical place’ prone to trauma.
Laminitis also leads to damage of the suspensory apparatus of the digita and support system of the pedal bone with subsequent displacement (sinking/rotation) of the pedal bone. This may account for slight variations in the location at which the pedal bone sinks. As a result there is a broad variety of ulcers of different size and located at slightly different sites.
Horn overgrowth is a common finding accompanying many claw diseases. It is not uncommon to see sole ulcers in neglected (very) long claws. In these cases, the abnormal shape of the claw shifts the load axially and backwards. This leads to a localized compression by the flexor process of the digital cushion and dermis against the inner surface of the sole.
Often it is difficult to distinguish between cause and effect. For example, a cow may seek relief from bearing weight on an established ulcer which will permit accelerated growth of the posterior, abaxial wall and bulb. This adds to the load borne by the claw and to the discomfort of the patient.
Sole ulcers can be a result of claw trimming if the operator is inexperienced. Producers should be discouraged from attempting to correct this disorder themselves.
A thin sole is not necessarily involved in the pathogenesis of an ulcer. Alteration of the pedal bone (formations of exostosis) was suggested as a possible etiology by Rusterholz (1920) who was the first to propose that the disorder develops from inside.
In complicated cases, infection may even travel up the deep flexor tendon sheath.
Cauterization or treatment with any caustic agent should be avoided. If the granulation tissue protrudes beyond the surface of the sole, it should only be removed to the level of surrounding tissue. This encourages the cells of the living epidermis to invade the surface of the granulated area from the periphery. In complicated cases, depending on the depth of destruction, the lesion will need protection. This can be provided by a plastic bag held in position with duct tape. The purpose is to avoid increasing pressure on the lesion itself.
Only in skilled hands is therapeutic claw trimming highly effective. This procedure lowers the entire bearing surface of the affected claw, transferring weight-bearing to the sound medial claw.
It is usually necessary to slightly trim the claw to provide a sound surface before a ‘lift’ is applied. Lifts may remain in place for 4 weeks, after which time they must be removed.
Recently, shoes or slippers are proving to be a popular type of lift. The devices are blocks of hard plastic shaped in the form of a sole to which a slipperlike upper has been fixed. The upper provides a convenient receptacle in which an adhesive can be mixed. In some cases, the trailing edge of a shoe (lift) may cause pressure on the sole which can eventually cause lameness. When lameness is observed to increase, the lift should be removed immediately and the claws re-examined.
Zones Affected: 4, 5
Prevalence: 2.0% of lesions recorded by Canadian hoof trimmers
Examples of Thin Sole:
Moisture may cause softening in the sole horn, predisposing it to an increase in wear. The rear lateral claw is the most affected due to its weight bearing function.
The protective function of the claw capsule is based on adequate sole thickness of roughly 7mm in the area of the toe. Sole thickness is a function of the rate of growth vs. the rate of wear, both of which are affected by several factors. Rates of wear have been associated with concrete surfaces, poor cow comfort, commingling of animals, poor horn quality, poor stock, and claw horn moisture. Of the above, claw horn moisture may be the most important, as prolonged water contact of the claw horn occurs in many dairy operations due to flush systems used to manage manure or from the water used in sprinkler systems to clean udders or to reduce heat stress.
The lateral claw of the rear leg is commonly more severely affected with thin soles than other claws. (Contusion of the corium of the sole is an important cause of lameness in confinement conditions and contributes to excessive sole horn wear.) The front claws are larger and have thicker soles compared with the rear claws. This results in lower moisture levels in the outer sole horn layers. Also, dairy cows often stand with their front legs on bedding and hind legs in the alleyway, where they are constantly exposed to moisture from manure and urine.
It is important to keep up a regular maintenance-trimming program with accurate records to help your dairy keep ahead of this potential problem. When possible try to reduce standing water, and improve the housing of your herd if you observe your cows not taking advantage of their bedding. When in doubt block up any affected claw to minimize down time for the cow.
source: Daniel Montoya, http://dairy-cattle.blogspot.ca/2006/04/thin-soles-and-lameness.html
Also called: Toe Necrosis, Apicalis Necrotica
Zone Affected: 1
Prevalence: 4.3% of lesions recorded by Canadian hoof trimmers
Examples of Toe Ulcer Lesions:
A mature cow affected with a toe ulcer will become progressively lame as the severity of the lesion advances. There will be a tendency for the animal to stride slightly forward (camp forward) on one or both feet.
Usually, toe ulcers do not affect heifers during their first lactation. However, in recent years, many heifers in Uruguay have been reported with this condition. It should be noted that this observation coincides with heavy feeding of concentrates in pastured animals.
The lesion starts as a slight hemorrhage in the white line in zone 1. In some cases, the horn in the sole around the initial lesion becomes stained with blood. In other cases, a yellow exudation of serum occurs.
Toe ulcers in cows are seen mostly in animals housed in free stalls, although it has been observed in cows housed in dry lots. It is most commonly present in herds in which subclinical laminitis is known to be a problem.
A precipitating factor appears to be over-wear of the toe (e.g., cows housed on slatted concrete floors). After some time, the animal refuses to bear weight on the apex of the claw. This results in an overgrown toe region with the weight being borne mainly by the bulbar region.
In extreme cases, the apex of the pedal bone will prolapse through the sole, producing a lesion reminiscent of the lesion that affects horses with acute laminitis.
Extensive damage of the dorsal wall of the claw, an occasional sequel to digital dermatitis, has also been seen to be associated with toe ulcers.
Not all lesions in the white line of zone 1 in mature cows can be classified as toe abscesses. Traumatic lesions can also be detected by applying physical pressure to the toe region with calipers.
Toe ulcers have been recognized only in relatively recent years. Their appearance has been concurrent to some extent with the increasing awareness of the prevalence of subclinical laminitis.
|One explanation of the cause of this disorder may be that the toe ulcer in mature cows is the result of rotation of the pedal bone inside the capsule. It has been suggested that the release of matrix metalloproteinasescauses the breakdown of the suspensory apparatus of the digit. The epidermo-dermal lamellae are particularly extensive under the dorsal wall of the claw capsule, therefore, failure of the suspensory apparatus in the region is likely to produce dramatic results. There is a progressive degradation of collagen fibrils by the activated form of MMPs weakening the suspension of the bone. As a result, the fibers between the lamellae and the bone either stretch or tear away from the inner surface of the wall. Depending on where the damage is most advanced, the displacement of the bone commences and exerts pressure onto the living tissues beneath. Excessively long periods standing (e.g., in a holding yard) probably accelerates this process.
Failure of the circulation in the apex of the claw can gradually cause rarification of the bone (osteolysis) which can be observed radiographically.
Temporary protection for a toe ulcer can be given by applying a layer of methyl methacrylate (MM). The exposed dermis should appear healthy and a layer of granulation tissue should be present.
Most lesions will require a few days preparation before MM can be safely applied. The first step, therefore, is to expose the area to an antibiotic. For this purpose, gauze impregnated with petroleum jelly and penicillin is very effective. The dressing should be bandaged in place with a waterproof cover for 48–72 hours. This procedure reduces the bacterial burden in the lesion. The horn around the affected area should be pared away and the surface lightly grooved to improve the adhesion of the acrylic. The exposed surface and prepared sole should be sterilized with alcohol and dried using a heat lamp or hair drier. Antibiotic powder should be applied to the tissue. The acrylic is then molded around the entire toe. Under normal temperature conditions, the curing of the methyl methacrylate must be slowed down considerably by running cold water over the acrylic. If this is not done, the heat generated will be extremely painful for the patient.
Some workers employ a plastic ‘slipper’ with a closed toe cup for this procedure. A useful tip is to make an insert cut from 5mm automobile inner tubing and place it inside on the sole of the shoe. This will provide better cushioning during weight-bearing. Adhesive is applied to the inside of the toe cap, but not to the sole. After the affected claw has been inserted into the shoe, adhesive should be applied to the sole wall and overlapped onto the toe cap.
If necrotic corium protrudes through the opening in the sole it is very likely that the apex of the pedal bone has suffered a physiological fracture. This type of fracture is caused by blockage, possibly pressure, cutting off the blood supply to the bone. Radiographic examination is recommended, and if the diagnosis of fracture is confirmed, the necrotic apex of the bone should be removed. This is a relatively simple procedure which would be strongly indicated if the animal is particularly valuable. An abscess in the white line at the apex of the sole can be caused by a foreign body.
Measures applied to control subclinical laminitis are likely to reduce the incidence of this condition. There is probably a traumatic component to the etiology of the disorder. Walking long distances, poor-quality concrete, and lack of good bedding could all increase the incidence of this phenomenon.
Also called: Sandcrack, Fissura Ungulae LongitudinalisZones Affected: 7, 8
Examples of Vertical Fissure:
Vertical fissures are cracks that run down the abaxial border of the dorsal surface of the wall. The majority (68%) are found on an outside front claw. Although the incidence of this condition is high in mature Canadian beef cows (~20%), the prevalence of lameness in affected cattle is low. Lameness occurs mostly when the crack becomes infected.
Cracked claws usually become bent and twisted over time. When this occurs, affected beef cows are reluctant to move, grazing time is reduced, and more time is spent lying down. For descriptive and research purposes, sandcracks can be divided into five different types.
A genetic factor involving the conformation of the forelimb may predispose to cracks appearing only in front lateral claws. Although there is no evidence to support this hypothesis, it has been suggested that the degree to which the foot turns in or out could be implicated.
There is a little more evidence to support the concept that beef cows with horizontal fissures also suffer more frequently from vertical fissures. This theory gains some support from the fact that many vertical fissures appear to originate at a horizontal fissure. When a horizontal groove or fissure grows out as far as the middle of the claw, the dorsal surface commences to bend around the defect. It is further proposed that the bending process generates mechanical stresses in the dorsal wall of the claw. The stress is relieved by the appearance of a crack. Half of all sandcracks run the full length of the claw; therefore, these may or may not be associated with a horizontal fissure. On the other hand, 11% of fissures start at a horizontal fissure.
An unusually high prevalence of sandcracks in beef cattle across the Canadian prairies is linked to factors unique to that region. This area is marginally deficient in both copper and zinc. The extremes of climate have given rise to a special system of management. Beef cattle are corralled during the winter months and subsist on forage low in protein and energy but high in fiber. Invariably, these animals are turned out to pasture in the spring only when the grass is lush. This means there is a sudden change in diet which introduces the cattle overnight to pasture, rich in protein and energy, but extremely low in fiber.
If the seat of lameness can be traced to a sandcrack, there is cause for concern. Particularly if the site of the lesion is abaxial to the extensor process, there is a significant risk that the pedal joint could become infected. If the cracks are small and only involve the coronary band, all detached horn should be removed but no part of the dermis (corium) should be touched for fear of penetrating the joint capsule. The lesion should be cleansed and dried. A topical dressing consisting of equal parts anhydrous copper sulfate and sulfamezathine should be applied and protected by a gauze pad held in place by an elastic bandage encircling the entire coronary band. Pressure bandaging is advisable, firstly because exuberant granulation tissue can be a problem, and secondly because the joint capsule is very vulnerable at this location.
Some cattlemen are concerned about the appearance of the claws of valuable and/or show animals. They are concerned that the appearance of the feet will detract from the sale of their stock. The ragged edges of a large sandcrack can be seen to move during weight-bearing. If the crack splits open at the apex of the claw, weight will be borne on each side of the crack, forcing each side apart.
The first step in a cosmetic procedure to improve the appearance of claw with a sandcrack is to cut back as far as possible the axial side of the crack at the apex of the claw. This causes weight to be borne only on one side of the fissure, thus avoiding movement of the two parts of the wall. The edges of the crack are next smoothed out. Holes about 8 mm (0.35 ins) in diameter are drilled along the edge of the crack angle into the fissure. Fetotomy wire is laced through these holes, like shoe laces, and methyl methacrylate applied as a reinforcement. The material left in place as the crack grows out some 8–12 months later.
Careful forage and pasture management can help reduce the incidence of sandcracks. Sudden changes occurring in the spring, when cattle move from a diet high in fiber and low in protein to pasture rich in protein and low in fiber, are believed to cause horizontal fissures. This is discussed in greater detail under horizontal grooves. Numerous research reports indicate that biotin is useful in reducing the incidence of this disorder.
Also called: White Line Separation, White Line Disease
Zones Affected: 1, 2, 3
Prevalence: 13.7% of lesions recorded by Canadian hoof trimmers
Examples of White Line Lesion:
White line lesion is a general term used to describe disintegration of the white line in zones 1, 2 or 3, together with any purulent complication of that lesion.
The lateral claw of the hind foot (often both) is usually involved. However, if both hind feet are affected, lameness may appear to be only slight. As in the case of a sole ulcer, pain in one foot tends to balance that in the other, thereby masking the severity of the discomfort.
As the animal walks, the affected limb will be swung away from the body during each stride. The animal may stand with the medial claw bearing weight.White line separation without complications is frequently seen at claw trimming. It is only when an abscess develops in the angle between the wall and the sole that the animal will become lame. When lameness is not observed and/or treatment is not given, several different clinical scenarios may be presented:
The build-up of pus in the retroarticular space can be confirmed by inserting a hypodermic needle and drawing the material into a syringe. The size of the abscess increases continuously, causing the surrounding tissues to suffer considerable damage. The main diagnostic clue is a slight increase in the size of one heel bulb compared with the other. Gas is sometimes observed in a radiograph.
The first impact of each stride is greatest at the heel/sole junction (zones 3 and 4). The digital cushion expands sideways when it is compressed under weight-bearing. Sideways expansion of the digital cushion causes pressure to be exerted on the wall above zone 3.
The abaxial end of the white line in zone 3 is the broadest part of the white line (width up to 5mm). Additionally, the softest horn of all areas of the white line is in this zone.
The highest rate of horn production occurs in the abaxial wall above zone 3. It is also believed that in this region the white line is particularly susceptible to alterations of the vascular system and subsequent disruption of nutrition.
Subclinical laminitis may cause stretching of the collagen fibres off all of the structures inside the claw capsule. Aging of the digital cushion reduces its anticoncussive capacity.
The application of a ‘lift’ is mandatory for the treatment of all complicated lesions of the claws.