Polyuria and Polydipsia in Horses.

Polyuria and polydipsia are rare, but significant, manifestations of several different diseases of horses. Causes can be endocrine, iatrogenic, psychogenic, infectious, or toxic in nature and can also be due to primary renal disease or diseases of other organs, such as the liver. Although numerous causes of polyuria and polydipsia in horses exist, the most common conditions include chronic kidney disease, pituitary pars intermedia dysfunction, and psychogenic polydipsia with secondary polyuria. Additional testing is dictated by history, other clinical signs, and the results of blood work and/or urinalysis. Prognosis for horses with polyuria and/or polydipsia varies significantly based on the underlying cause.

Combined tube cystostomy and urethrotomy for the treatment of urethral obstruction due to urolithiasis in goats.

OBJECTIVE: To describe the treatment of goats with urethral obstruction secondary to urolithiasis by combining tube cystostomy and urethrotomy. ANIMALS: Eight male goats. STUDY DESIGN: Short case series. METHODS: Medical records (September 2012-September 2017) of male goats treated for obstruction secondary to urolithiasis with tube cystostomy and urethrotomy were reviewed. Data collected included signalment, history, physical examination findings, diagnostic results, perioperative treatments, operative details, hospitalization duration, intraoperative and postoperative complications, urolith analysis, and time to restoration of urethral patency. Long-term follow-up (>12 months) was obtained by email or telephone interviews of owners or by clinical examination. RESULTS: Seven of eight goats were castrated males of various of breeds. All goats were tachycardic with urethral pulsation at admission. Uroliths were composed of calcium carbonate in four goats and silica in one goat. All goats regained urethral patency during hospitalization, and all were discharged alive from the hospital. Seven goats were alive at long-term follow-up. Postoperative complications included persistent urethral obstruction requiring a second urethrotomy 2 days postoperatively, premature dislodgement of the bladder catheter and jejunal obstruction secondary to adhesions, and recurrence of obstructive urolithiasis within the proximal perineal urethra requiring a second surgery 8 months later (1 each). Long-term outcome was good, with urethral patency beyond 12 months in six of eight goats. CONCLUSION: Combining tube cystostomy and urethrotomy restored urethral patency in goats with urethral obstruction from uroliths. Although none of the complications seemed directly related to the urethrotomy, formation of abdominal adhesions and recurrence of urolithiasis affected long-term outcomes. CLINICAL SIGNIFICANCE: Uroliths that do not dissolve in acidic urine may be more frequent in some practices. The combined approach of tube cystostomy and urethrotomy appears to successfully restore urethral patency with promising long-term outcomes.

Pharmacokinetics and bioavailability of oral firocoxib in adult, mixed-breed goats.

Pharmacokinetic (PK) studies of oral firocoxib in large animal species have been limited to horses, preruminating calves, and adult camels. The aim of this study was to describe pharmacokinetics and bioavailability of firocoxib in adult goats. Ten healthy adult goats were administered 0.5 mg/kg firocoxib intravenously (i.v.) and per os (p.o.) in a randomized, crossover study. Plasma firocoxib concentrations were measured over a 96-hr period for each treatment using HPLC and mass spectrometry, and PK analysis was performed. The p.o. formulation reached mean peak plasma concentration of 139 ng/ml (range: 87-196 ng/ml) in 0.77 hr (0.25-2.00 hr), and half-life was 21.51 hr (10.21-48.32 hr). Mean bioavailability was 71% (51%-82%), indicative of adequate gastrointestinal absorption of firocoxib. There were no negative effects observed in any animal, and all blood work values remained within or very near reference range at the study's conclusion. Results indicate that oral firocoxib is well-absorbed and rapidly reaches peak plasma concentrations, although the concentration also decreased quickly prior to the terminal phase. The prolonged half-life may suggest tissue accumulation and higher plasma concentrations over time, depending on dosing schedule. Further studies to determine tissue residue depletion, pharmacodynamics, and therapeutic concentrations of firocoxib in goats are necessary.

Acute leukemia in six horses (1990-2012).

Acute leukemia is rare in horses. Herein we describe historical, clinicopathologic, and postmortem findings in 6 horses with acute leukemia. Medical records of horses with >20% bone marrow blasts and cytochemical or immunophenotyping results were reviewed. Affected horses were 2-8 y of age and of different breeds and sex. Horses were presented acutely with nonspecific signs (e.g., fever, lethargy). Characteristic hemogram findings were bi- or pancytopenia with low blast numbers. Histologic examination revealed extramedullary infiltrates, especially in lymph nodes, spleen, kidney, liver, and lungs. Leukemias were classified as B-cell ( n = 3) and acute myeloid leukemia (AML) ( n = 3). Tumors in 4 cases expressed multiple lineage markers, which complicated classification. Acute leukemia should be suspected in horses with moderate-to-severe bi- or pancytopenia. Blood smears should be reviewed for neoplastic cells, and bone marrow examination is required for diagnosis. Leukemia classification is best achieved using combined morphologic, cytochemical, and immunophenotyping results.

Recurrence of renosplenic entrapment after renosplenic space ablation in a seven-year-old stallion.

CASE DESCRIPTION: A 7-year-old mixed-breed stallion was admitted because of colic. CLINICAL FINDINGS: Entrapment of the left colon in the renosplenic space was diagnosed via rectal palpation and ultrasonographic examination, despite a renosplenic space ablation 6.5 years earlier. TREATMENT AND OUTCOME: The renosplenic entrapment was corrected with a combination of phenylephrine administration, rolling, and ballottement of the horse's abdomen during general anesthesia. The following week, left flank laparoscopic renosplenic space ablation was performed with the horse standing. On examination of the previous surgical site, only 4 bands of fibrous adhesion remained of the original space ablation. The renosplenic space was again closed by suturing the perirenal fascia and renosplenic ligament to the splenic capsule. The horse was discharged from the hospital and recovered at home. No complications or recurrence of entrapment was reported following the procedure. CLINICAL RELEVANCE: There have been no previous reports of recurrence of renosplenic entrapment following procedures to permanently ablate the renosplenic space. Recurrence in this patient may be attributed to the horse's young age at the time of initial surgery or inadequate size or spacing of the sutures through the perirenal fascia and splenic capsule.