Pharmacokinetics and efficacy of intravenous famotidine in adult cattle.

BACKGROUND: Abomasal ulceration is recognized in neonatal and adult cattle, but research regarding treatment is limited. Histamine-2 receptor antagonists (H2 RA), such as famotidine, are used clinically with little evidence-based research about efficacy in adult cattle. HYPOTHESIS AND OBJECTIVES: Intravenous famotidine administered at 0.4 mg/kg will increase the pH of abomasal outflow digesta compared to saline control in adult cattle. The objectives were to assess the effect of famotidine, administered as a single dose and as multiple doses, on abomasal outflow fluid pH in adult cattle. A third objective was to describe the pharmacokinetic parameters of IV famotidine in cattle. ANIMALS: Four clinically healthy adult Angus-cross steers previously fitted with duodenal cannulae placed orad to the biliary and pancreatic ducts. METHODS: Randomized, 2-way cross-over clinical trial. Steers received IV famotidine (0.4 mg/kg) as a single and 3-dose regimen (every 8 hours) versus saline control. Blood for analysis of serum famotidine concentration was collected intermittently for 12 hours, and abomasal outflow fluid pH was measured at intervals for a 24-hour period. After a 34-hour washout period, the opposite treatments were administered and the sampling repeated. RESULTS: Abomasal outflow fluid pH was higher in steers treated with famotidine for up to 4 hours after a single dose but the effect decreased with subsequent doses. The median (range) elimination half-life was 3.33 (3.21-3.54) hours. CONCLUSIONS AND CLINICAL IMPORTANCE: Famotidine may be useful for treatment or prevention of abomasal ulceration in adult cattle, but the duration of effect may decrease with time.

Comparative pharmacokinetics of two florfenicol formulations following intramuscular and subcutaneous administration to sheep.

OBJECTIVE To compare the pharmacokinetics of 2 commercial florfenicol formulations following IM and SC administration to sheep. ANIMALS 16 healthy adult mixed-breed sheep. PROCEDURES In a crossover study, sheep were randomly assigned to receive florfenicol formulation A or B at a single dose of 20 mg/kg, IM, or 40 mg/kg, SC. After a 2-week washout period, each sheep was administered the opposite formulation at the same dose and administration route as the initial formulation. Blood samples were collected immediately before and at predetermined times for 24 hours after each florfenicol administration. Plasma florfenicol concentrations were determined by high-performance liquid chromatography. Pharmacokinetic parameters were estimated by noncompartmental methods and compared between the 2 formulations at each dose and route of administration. RESULTS Median maximum plasma concentration, elimination half-life, and area under the concentration-time curve from time 0 to the last quantifiable measurement for florfenicol were 3.76 µg/mL, 13.44 hours, and 24.88 µg•h/mL, respectively, for formulation A and 7.72 µg/mL, 5.98 hours, and 41.53 µg•h/mL, respectively, for formulation B following administration of 20 mg of florfenicol/kg, IM, and 2.63 µg/mL, 12.48 hours, and 31.63 µg•h/mL, respectively, for formulation A and 4.70 µg/mL, 16.60 hours, and 48.32 µg•h/mL, respectively, for formulation B following administration of 40 mg of florfenicol/kg, SC. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that both formulations achieved plasma florfenicol concentrations expected to be therapeutic for respiratory tract disease caused by Mannheimia haemolytica or Pasteurella spp at both doses and administration routes evaluated.

Use of a percutaneous transabdominal catheter for management of obstructive urolithiasis in goats, sheep, and potbellied pigs: 69 cases (2000-2014).

OBJECTIVE To evaluate the use of a percutaneous transabdominal catheter (PTC) for urinary bladder drainage in goats, sheep, and potbellied pigs with obstructive urolithiasis. DESIGN Retrospective case series. ANIMALS 43 goats, 10 sheep, and 16 potbellied pigs (all males) with obstructive urolithiasis evaluated at the University of California-Davis Veterinary Medical Teaching Hospital. PROCEDURES Medical records of goats, sheep, and potbellied pigs examined because of obstructive urolithiasis from January 2000 through December 2014 were reviewed. Records of animals for which a standard PTC had been placed into the urinary bladder as part of disease management were selected. Data were collected regarding signalment, complications associated with PTC placement, and duration of PTC placement prior to removal. RESULTS 42 of 43 goats, 5 of 10 sheep, and all potbellied pigs were castrated. Median (range) duration of PTC placement was 2 (1 to 4) days for goats, 1 (1 to 4) day for sheep, and 1 (1 to 3) day for potbellied pigs. Complications associated with PTC placement included blockage of the catheter by urine sediment, perforation of the cecum, and migration of the catheter out of the urinary bladder. CONCLUSIONS AND CLINICAL RELEVANCE Placement of a PTC into the urinary bladder allowed for effective stabilization of goats, sheep, and potbellied pigs with obstructive urolithiasis while acid-base and electrolyte imbalances were corrected. Use of a PTC should be considered for urinary bladder drainage during medical management or prior to surgical management of obstructive urolithiasis for these species.