Win the Lame Game

Nigel Cook, BVSc, University of Wisconsin ( Tom Bennett, University of Wisconsin )

Worldwide, about 23% of dairy cattle experience lameness issues, with three types of hoof lesions causing most of those problems, says University of Wisconsin veterinarian Nigel Cook, BVSc.

Cook recently provided an overview titled “Lifestep – a lesion-oriented approach to solving lameness problems” in a webinar hosted by the Dairy Cattle Welfare Council (DCWC). He says digital dermatitis, sole ulcers and white line disease cause most lameness issues in dairies. Thin soles and toe ulcers also appear to be increasing in some operations, but Cook says prevention efforts for the top three lesions could have a significant impact on dairy welfare and performance.

The Wisconsin Dairyland Initiative offers its Lifestep Lameness Module on its website. Cook says the “Lifestep” term intends to communicate the lifelong nature of lameness problems and stress the importance of prevention measures at all stages of a cow’s lifecycle. He illustrated this point with data on digital dermatitis (DD) collected by his colleague Dr. Dorte Dopfer. In cows that did not experience a DD event during the development phase, just 13.7% developed DD during their first lactation. In cows that experienced one case of DD during development, the incidence during first lactation jumped to 45.6% and for those with two or more cases during development the incidence was 67.6% during first lactation.

Cook lists these research-based factors shown to reduce lameness risk in dairy cattle:

  • Less standing time on concrete
  • Deep bedded comfortable stalls rather than mats or mattresses
  • Wider stalls with fewer obstructions to rising and lying movements
  • Use of manure removal systems other than automatic scrapers
  • Use of non-slippery, non-traumatic flooring rather than slats.
  • Access to pasture or outside exercise lot
  • Use of a divided feed barrier rather than a post and rail system
  • Wider feed alleys
  • Access to a trim chute for treatment and use of an effective foot-bath program
  • Prompt recognition and treatment of lameness

Hygiene, genetics, nutrition and facilities all play a role in prevention of DD at all life stages, Cook says. Foot baths using copper sulfate (2 to 5%) or formaldehyde (2 to 4%) provide a key prevention tool. For antimicrobial stewardship reasons, Cook advises against using antibiotics in foot baths. The bath should be long enough for two to three immersions per foot, ideally around 10 to 12 feet long and two feet wide. As long as recommended solutions are prepared to the proper concentrations and changed frequently, the length of the bath has a greater impact on efficacy than the type of solution.

Cook lists these best management practices for footbaths:

  • Use a well-designed footbath with adjacent mixing facilities.
  • Provide a footbath at four milkings per week and adapt based on outcome to achieve a minimum frequency to maintain control.
  • Use an antibacterial with evidence of efficacy against DD and footrot. Mix copper sulfate at a concentration no higher than 5%. Acidify the solution to a pH no lower than 3.0. Use Formaldehyde at a concentration no higher than 4% and avoid its use in cold weather.
  • Use the solution as long as it is effective, generally 150 to 300 cow passes.
  • Do not forget to include all life stages of the cow.

White line disease typically occurs with poor flooring and poor handling, Cook says, with animal handling especially critical. Some dairies with poor to marginal flooring avoid problems with white line disease by focusing on good handling practices including observing flight zones and balance points.

Surfaces

Flooring can play a role in most types of lameness, and Cook says dairies increasingly are turning to rubber flooring in milking areas and transfer lanes. Rubber flooring in freestall pens, however, can reduce the time cows spend lying down and thus potentially contribute to lameness problems. Cows should spend about 12 hours per day resting, and deep, loose bedding such as sand in freestalls facilitates that behavior. Sand is the most common bedding in Wisconsin, but Cook says sawdust, straw, paper or manure solids can provide a good surface. He adds that firm mats or mattress surfaces in pens make it difficult for cattle to lie down and stand back up, especially if they already show signs of lameness.

Done right, concrete floors can provide good footing for cows. Older concrete floors with exposed aggregate should be resurfaced and grooved for traction. Cook suggests using a concrete-cutting machine to create .75-inch grooves, .5-inch deep and 3.25 inches center to center.

Slatted floors increase the risk of claw trauma and cows prefer not to walk on them, Cook says.

Heat Stress

Heat plays a key role in cattle behavior related to lameness, Cook says. In hot conditions, cows tend to accumulate heat while lying and cool down when they stand. Rest time can drop by four hours per day during a six-day heat wave, elevating the risk of lameness. Air movement in the stalls helps cows lose heat and facilitates rest during hot weather. Cook recommends positioning fans over all rows of stalls, with capacity to move air at around 200-400 feet per minute and set to activate at 65 degrees Fahrenheit.

Cook says “reverse corkscrew claw” has appeared in the rear, medial claw in younger animals. Causes remain unclear, but he theorizes that competition for feed could play a role, particularly where headlocks are used at the feed bunks and sand bedding in the stalls. Heifers push against the headlock trying to reach more feed, putting excess pressure on their rear feet, which could cause the corkscrew deformity in the medial claw in young cattle. The sand bedding maybe altering the growth and wear rates of the sole horn putting animals at increased risk. In heifer facilities he says, some operations are shifting to post-and-rail bunks instead of headlocks and utilizing other forms of deep bedded rather than sand.

With proper management, Cook says, research shows dairies can achieve high milk production while minimizing lameness. In a recent survey of 66 elite Wisconsin herds, researchers identified the incidence of these housing and management characteristics:

  • Deep, loose bedded stalls: 70%.
  • Two-row stll layout for pen: 61%.
  • Headlocks at the feedbunk: 83%.
  • Solid floors (versus slats): 100%.
  • Manual manure removal from alleys (versus scraper): 73%.
  • Rubber freestall alley flooring: 5%.
  • Rubber parlor flooring: 68%.
  • Fans over resting areas: 96%.
  • Outside access: 9%.
  • Trim cows’ feet at least once per lactation: 88%.
  • Footbath frequency: Average of 4.5 times per week.

Cook encourages veterinarians to help clients collect and use records on lameness incidence, types and severity of lesions, and apply the information toward genetics, management and facilities decisions.

Vigilance, Early Detection for DD

Digital Dermatitis (DD) is a common and growing cause of lameness in dairies and, increasingly, in cattle feedlots. Dörte Döpfer, DVM, PhD, at the University of Wisconsin, notes that DD is a multifactorial, infectious, superficial dermatitis of the digital skin of cattle that may be very painful upon touch and has a characteristic fetid odor.

The most common site of DD lesions is the palmar/plantar interdigital ridge of the foot – especially the rear feet, but other sites include the skin of the interdigital cleft where they can be found on Interdigital Hyperplasias (Corns), the skin around the dew claws, the heel, sometimes under-running the sole, and the dorsal aspect of the coronary band, where they may be associated with a vertical wall crack. A white epithelial margin and overlong hair have been described around acute ulcerative DD lesions while more chronic stages of DD are associated with dyskeratosis, filamentous or mass-like epithelial proliferations, Döpfer says.

DD is not the same as footrot, Döpfer stresses, and unlike footrot, neglected or established cases of DD are irreversible. Once cattle become lame from DD, treatment success is low.

Early or intermediate DD lesions are small circumscribed epithelial defects that have been described as “Focal Bacterial Keratolysis,” Döpfer says. Neglected cases of acute ulcerative DD may develop painful phlegmones and infections of the deep digital structures that may require surgical care for recovery. DD, she adds, is considered a multifactorial infectious claw disease with a strong bacterial component. Best candidates for etiological bacterial agents of DD are spirochetes of the Treponema species, closely related to Treponema phagedaenis, T. vincentii/T. medium, and T. denticola.

Döpfer and her colleagues have developed a scoring system to classify the different stages of digital dermatitis, the M-stages system, where "M" stands for Mortellaro. The different stages are described as:

  • M0, healthy skin;
  • M1, early stage, skin defect < 2 cm diameter.
  • M2, acute active ulcerative lesion, >2 cm in diameter.
  • M3, healing stage, lesion covered with scab-like material.
  • M4, chronic stage, that may be dyskeratotic (mostly thickened epithelium) or proliferative or both.
  • M4.1, a chronic M4 stage combined with an M1

Diagnosis is principally based on history and clinical signs. It is very rare that attempts are made to isolate the bacteria in practice.

In a recent feedlot study, Döpfer and her team conducted histologic diagnosis of 144 biopsies, and found only four classified as normal (3 M0 and 1 M4 with hyperkeratosis), with the rest classified as having histopathological signs of DD.

Using dark field microscopic evaluation, the researchers found spirochetes in 66% of biopsies processed. Statistical modeling showed that lesion type, presence of other microorganisms, and steer type potentially increased the probability for invasion by spirochetes into the stratum spinosum and papillary dermis.

As for prevention and management of DD in beef and dairy herds, Döpfer says organic trace-mineral intervention can reduce DD risk by about half, particularly if supplementation starts early during the finishing period.

Prompt treatment of active M2 lesions will reduce the spread of DD while reducing the incidence of lameness. Treatment requires the lifting of the foot, cleaning of the lesion, and applying topical oxytetracycline. Döpfer recommends 2g of oxytetracycline (OTC) per treatment, unless M2 lesions are detected early without any signs of chronicity such as hyperkeratosis or proliferation. If detected early, superficial disinfection can make the lesions reduce in size and severity before a disinfecting footbath maintains the non-ulcerated state of the skin surface. M4 lesions are a reservoir for future outbreaks, she says. Treponemes lie deep within the skin and can become active at any point. Running cattle through a footbath two to three times per week should keep the lesion in the chronic non-active M4 stage. Depending on preference, formalin, or copper sulfate solution will serve as an antibacterial and hoof hardening solution. Once the transmission cycle is broken, claw disinfecting footaths can be filled with 1% bleach or soap water to substitute copper sulfate and formalin. All footbath solutions have pros and cons, she says, and you can read more about footbath options at this University of Wisconsin website: https://fyi.uwex.edu/dairy/resources/animal-well-being-herd-health/.

Döpfer stresses these points in managing DD in cattle:

  • M2 lesions deserve attention, but when you lift a foot to treat an M2 lesion, you have fallen behind.
  • Treponemes encyst and hide in M4 lesions, and the immune system does not detect them.
  • Spirochetes reside deeper in the dermis than expected.
  • Dynamics of DD are driven by chronic lesions, not just active. Particular attention should be given to reduction of chronic lesion formation, because those represent reservoirs of infection with treponemes that are considered to be associated with the etiology of DD.
  • Customized footbathing should be aimed at reducing the amount of copper sulfate and formalin to the point where no proliferative M4 lesions occur, because this prevents outbreaks of M2 from chronically affected cattle
  • While most commonly associated with dairies, research increasingly shows DD as a significant cause of lameness in beef cattle.
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