Management of beef cattle lameness can be frustrating for veterinarians and producers. But compared to our one-toed equine patients, we have two toes to work with on each foot. This presents some treatment and pain-management options not available for all species. The following article details treatment options I've become familiar with in practice.
Management of beef cattle lameness can be frustrating for veterinarians and producers. But compared to our one-toed equine patients, we have two toes to work with on each foot. This presents some treatment and pain-management options not available for all species. The following article details treatment options I've become familiar with in practice.
A wooden, plastic or rubber hoof block removes the source of pain by preventing weight bearing on the effected claw and allows the animal to ambulate comfortably while healing takes place. This is effective for treatment of P3 fracture and is essential for treatment of sole ulcers and serious hoof cracks. Blocks 1 inch to 2 inches thick, cut to fit the shape of the claw with grooves on both sides, are glued to the hoof using some type of bonding material.
Lameness is a common problem presented to bovine practitioners and has been known to cause great economic loss.
There are plenty of material options available, but preparation of the claw is crucial. Make sure the claw is clean, dry and level. Shallow grooves can be made in the sole with a hoof knife, but they are not necessary in my opinion. Bonding materials can set up quickly, so have everything ready. In cold, wet weather, a hair dryer helps to quicken setup. When applying the acrylic, pay particular attention to the axial surface, making sure its smooth and will not irritate the interdigital space or the axial surface of the opposite claw. Do not spread the acrylic onto the coronary band or up to the soft part of the heel. Make sure the block is positioned so the animal does not rock back on its heel and the toe does not tip up.
Caution: If the lameness worsens with the hoof block on, remove it immediately. If the animal develops lameness after wearing the block for several days, re-evaluation of the lameness is indicated. The hoof block might be causing it. Also, heat produced during the hardening process can cause thermal necrosis of soft tissues under the hoof wall. Use bonding materials sparingly on the hooves of young calves.
Acrylic also can be used alone or in combination with wire to repair hoof-wall defects. However, the hoof defect must be clean, dry and free of infection before the acrylic can be placed over it.
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Intravenous local anesthesia is my preferred technique for surgical procedures of the foot and pastern. Although clipping is not necessary, a surgical scrub should be performed prior to injection. A tourniquet is placed proximal to the fetlock immediately prior to injection (vein will be distended best immediately after tourniquet is placed). Two sites of injection are available. One vein runs down the center of the dorsal aspect of the pastern and the other runs approximately 2 cm dorsal to the dewclaw on the lateral and medial sides of the foot. A 20-gauge needle or butterfly catheter is inserted into the vein, and 15cc to 20cc of lidocaine is administered. It is only necessary to block one of these veins to provide anesthesia to the entire area distal to the tourniquet. The tourniquet can be safely left on for up to one hour to provide hemostasis during surgical procedures.
In feet with severe cellulitis, local intravenous anesthesia can be difficult. In these cases, a four-point nerve block or a simple ring block also will work (see "Beef cattle lameness: diagnostic strategies," in DVM Newsmagazine's February issue). The two interdigital injections performed in the four-point block can be used for removal of an interdigital fibroma.
The same local intravenous technique described previously can be used to administer antibiotics. Much higher levels of drugs can be achieved in the tissues distal to the tourniquet with this technique compared to systemic administration. Although penicillin salts (sodium and potassium) have been used, they are not always available. Ceftiofur sodium (not ceftiofur HCl) and ampicillin have been used successfully. We routinely use 500 mg of ceftiofur sodium. This technique can be used for early septic arthritis, cellulitis or as an adjunct therapy for surgical procedures for severe arthritis or osteomyelitis (bone curretage, coffin-joint arthrodesis). In some cases, repeated daily injections are necessary. An 18-gauge, 2-in. catheter can be placed in the vein to facilitate repeated injections without the need for tilt table restraint. Alternatively, if the animal's disposition allows, a tourniquet can be placed on the limb with the animal restrained in a chute and a butterfly catheter used for injection.
Septic arthritis is a serious condition that requires immediate treatment. Although it is tempting to first try systemic antibiotics alone, the chances of this working are low, and if systemic antibiotics fail, the disease might have progressed to the point that the joint can't be saved. For joint lavage to be successful, it needs to be performed very early (first few days) in the course of the disease. Because veterinarians rarely see these cases early, this is not a common technique used for treatment of the coffin, pastern or fetlock joint. The coffin joint is especially difficult to tap in cattle. If a needle can be placed in the joint space, a bag of isotonic fluids can be hooked to it, the fluid placed under pressure to distend the joint. Another needle placed in the joint space and a through and through lavage is performed. The larger the needle (14 gauge to 16 gauge), the better the lavage. Intra-articular antibiotics can be administered (100 mg ceftiofur sodium) with or without prior flushing. If the joint cannot be tapped, local intravenous infusion of antibiotics can be administered. Systemic antibiotics can be given in conjunction with these therapies.
When septic arthritis has advanced to the point that there are radiographic changes in the bone surrounding the joint, two options exist: claw amputation and coffin-joint arthrodesis. Coffin joint arthrodesis is preferable in valuable breeding animals, especially bulls, because it saves the claw. Although the procedure is easy to perform and relatively inexpensive, the aftercare (flushing wound, bandage changes, keeping a hoof block on and toes wired together, and/or cast application) can be prolonged, which increases the cost over amputation. Also, if significant cellulitis is present or there is radiographic evidence of osteomyelitis proximal to the coffin joint, the success rate of arthrodesis is poor, and amputation should be considered. The procedure is performed under local anesthesia, and only requires a shop drill and one-fourth-inch sterilized drill bits. Owners should be aware that time to breeding soundness might be several months even once the actual infection is cleared.
Analgesics can be important, especially if the animal is in enough pain to prevent it from eating. However, some pain might be beneficial to prevent movement, especially when surgery has been performed. It is my clinical experience that phenylbutazone is the most effective analgesic for lame cattle. I use a loading dose of 8 mg/lb followed by 2 mg to 4 mg/lb daily. I rarely have seen side effects as long as the animal is eating. The first sign of any side effects in my experience is anorexia, followed by mild diarrhea, which should subside when the phenylbutazone is discontinued.
Caution: Phenylbutazone must be kept out of the food supply because it can cause serious idiosyncratic reactions in people. It is prohibited for use in dairy cattle older than 20 months. Phenylbutazone should be reserved for valuable beef cattle with chronic osteoarthritis where slaughter is not an option. Previously recommended meat withdrawals for phenylbutazone are 45 days for the first dose and five days for each subsequent dose.
Dr. Navarre is associate professor of large animal internal medicine at Auburn University's College of Veterinary Medicine.