Page 187 - The Welfare of Cattle

164 the WeLfare of CattLe

lame cattle is included in third-party welfare audits, including the FARM program, the New York
State Cattle Health Assurance Program (NYSCHAP) and Validus. 78–80
Lameness, unlike the previously discussed painful procedures, does not have a known start point.
Lameness is found by producers and animal caretakers. The time from when the animal starts to
experience pain to the time when the lameness is treated is not known. This has been the impetus
for the early detection and treatment of lameness. Locomotion scoring systems have been developed
for routine detection of lame cattle. Early detection and treatment of lameness is obviously suggested
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but may also prevent central sensitization. Central sensitization is responsible for the observed
pain-related behavioral changes through increased sensitivity of pain (hyperalgesia) and pain from
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non-painful stimuli (allodynia). Analgesic treatment difficulties in chronic lame cattle may be best
explained through the aforementioned central sensitization based on current pain models. As a result,
preemptive analgesia that is usually advocated is difficult—if not impossible—to implement in lame
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cattle. Recommendations for the treatment of lameness include a multimodal approach that includes
the use of therapeutic trimming, hoof blocks, and pharmaceutical analgesics. 20
Causes of lameness can be infectious or noninfectious. Infectious causes of lameness include
foot rot (interdigital phlegmon) and digital dermatitis. Noninfectious causes include sole ulcers, toe
ulcers, white-line disease, and bone fractures. It is important to note that both infectious and nonin-
fectious lameness may be present in any clinical case.
Prevention is the most useful tool for the reduction of lameness on farms. Prevention strategies
should be targeted for the control of both infectious and noninfectious lameness causes. Farm and
cattle environmental cleanliness is the mainstay of prevention for controlling infectious lameness.
This is accomplished though frequent cleaning of fecal material and water in pens and alleys; the
use of footbaths containing antibiotics, salts, or antiseptics; and minimizing movement through
muddy areas. A regular hoof trimming schedule is a key component of prevention programs.
Hoof trimming maintains appropriate weight balance on the foot and allows for early diagnosis of
lesions. Nutrition, calving management, and environmental management all factor into prevention
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of noninfectious causes of lameness, but these strategies are beyond the focus of this chapter.
Pharmacologic management of pain associated with lameness is dependent on the cause of
disease and also the duration of the lameness. There are numerous antibiotics in the United States
labeled for treatment of foot rot. Although very important in the overall treatment of lameness,
antibiotics do not provide any analgesic effects.
In the United States, a novel formulation of the NSAID flunixin meglumine has been approved
for the control of pain associated with foot rot. This is the first drug to be given FDA approval for
pain mitigation in cattle. This novel formulation has transdermal absorption, thus allowing safe,
easy, convenient, and needleless dosing. In documents supporting the approval of the new flu-
nixin meglumine formulation, cattle were experimentally infected with Fusobacterium necropho-
rum, the causative agent of bovine foot rot. Infected calves had improved lameness by 48 hours
postinfection. 82
The use of intravenously injected flunixin meglumine has been studied in both a clinical study
and also an amphotericin B lameness model study. In the clinical study, lame cattle were adminis-
tered flunixin meglumine immediately before corrective hoof trimming and 24 hours following the
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first treatment. Gait scores as determined by a visual analog scale (VAS) and weight distribution
were not significantly affected by the provision of analgesia. Cows treated with flunixin had shorter
laying times than untreated controls. A mild significant reduction in variation (SD) of weight dis-
tribution of the rear legs was observed following analgesia administration as observed acutely with
lidocaine or ketoprofen administration. 83–85
A study using flunixin meglumine following lameness induction using amphotericin B showed
an improvement in lameness. Cattle treated with flunixin meglumine had improved lameness
scores, placed more pressure and surface area contact on pressure mats with their affected foot
as well as the contralateral claw of the affected foot. Cortisol concentrations were numerically