Local intravenous antibiotics
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.
Joint injection and lavage
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.