Carla S. Sommardahl

Effects of intravenously administrated omeprazole on gastric juice pH and gastric ulcer scores in adult horses.

The study was performed to evaluate the efficacy of omeprazole powder in sterile water, administered intravenously, on gastric juice pH in adult horses with naturally occurring gastric ulcers. Omeprazole (0.5 mg/kg, IV) was administered once daily for 5 days to 6 adult horses with gastric ulcers. Gastric juice was aspirated through the biopsy channel of an endoscope and pH was measured before and 1 hour after administration of omeprazole on day 1, and then before and after administration of omeprazole on day 5. Gastric ulcer scores were recorded on day 1 before administration of omeprazole and on day 5, 23 hours after the 4th daily dose. Gastric juice pH and ulcer scores were compared between the times. When compared with the pre-injection value (2.01 +/- 0.42), mean +/- SD gastric juice pH was significantly higher when measured 1 hour after administration of the initial dose (4.35 +/- 2.31), and before (5.27 +/- 1.74) and 1 hour after (7.00 +/- 0.25) administration of omeprazole on day 5. Nonglandular gastric ulcer number score significantly decreased from a mean +/- SD of 3.2 +/- 0.80 to 2.0 +/- 1.1, but nonglandular gastric ulcer severity score remained the same. Few glandular ulcers were seen in the study, and scores did not change. Because of its potent and long duration of action on gastric juice pH, this intravenous formulation of omeprazole may show promise for treatment of equine gastric ulcer syndrome (EGUS) in horses with dysphagia, gastric reflux, or other conditions that restrict oral intake of omeprazole paste. Aspiration of gastric juice and measurement of pH can be of use to determine whether the desired pH > 4.0 has been reached after omeprazole treatment.

A Multicenter Retrospective Study of 151 Renal Biopsies in Horses

BACKGROUND Renal biopsies are uncommonly performed in horses and little is known about their diagnostic utility and associated complication rate. OBJECTIVE To describe the techniques, the complication rate, risk factors, and histopathology results; as well as evaluate the safety and diagnostic utility of renal biopsy in the horse. ANIMALS One hundred and forty-six horses from which 151 renal biopsies were obtained. Animals ranged in age from 48 hours to 30 years. METHODS Multicenter retrospective study, with participation of 14 institutions (1983-2009). RESULTS Renal biopsy in horses was associated with a similar rate of complications (11.3%) to that occurring in humans and companion animals. Complications were generally associated with hemorrhage or signs of colic, and required treatment in 3% of cases. Fatality rate was low (1/151; 0.7%). Biopsy specimens yielded sufficient tissue for a histopathologic diagnosis in most cases (94%) but diagnoses had only fair (72%) agreement with postmortem findings. Risk factors for complications included biopsy specimens of the left kidney (P = .030), a diagnosis of neoplasia (P = .004), and low urine specific gravity (P = .030). No association with complications was found for age, sex, breed, institution, presenting complaint, other initial clinicopathologic data, biopsy instrument, needle size, or use of ultrasonographic guidance. CONCLUSIONS AND CLINICAL IMPORTANCE Renal biopsy in horses has low morbidity and results in a morphological histopathologic diagnosis in 94% of cases. However, this procedure might result in serious complications and should only be used when information obtained would be likely to impact decisions regarding patient management and prognosis.

Successful treatment of a sinonasal cryptococcal granuloma in a horse

CASE DESCRIPTION A 12-year-old 500-kg (1,100-lb) American Quarter Horse mare was evaluated because of chronic mucopurulent, bloody discharge from the left nostril, inspiratory dyspnea, and respiratory noise. CLINICAL FINDINGS The horse had severe inspiratory dyspnea and stertorous respiration with no airflow from the left nostril. A temporary tracheostomy was performed. Endoscopy revealed a tan mass protruding from the left middle nasal meatus into the left common nasal meatus; it extended caudally into the nasopharynx and around the caudal edge of the nasal septum into the right nasal cavity. Radiographically, a soft tissue opacity was evident in most of the left nasal cavity and left paranasal sinuses. Cytologic examination of mass tissue revealed evidence of pyogranulomatous rhinitis; thickly encapsulated, budding yeast typical of Cryptococcus neoformans were detected. TREATMENT AND OUTCOME While the horse was sedated and in a standing position, the fungal granuloma was removed from the paranasal sinuses. Treatment with fluconazole (5 mg/kg [2.27 mg/lb], PO, q 24 h for 4 weeks) was initiated; enilconazole (50 mL of a 10% solution) was instilled into the paranasal sinuses every other day (7 lavages). Six weeks after surgery, infection had not recurred and epithelialization appeared normal in the left paranasal sinuses. CLINICAL RELEVANCE In horses with cryptococcosis of the paranasal sinuses, surgical removal of granulomatous lesions and systemic and topical administrations of antifungal drugs may be curative. Successful surgery may be performed in standing horses. Concommitant removal of a large portion of the conchae allows follow-up rhinoscopic evaluation of the paranasal sinuses.

Effects of intravenously administered esomeprazole sodium on gastric juice pH in adult female horses.

BACKGROUND Gastric ulcers are common in horses and treatment of horses that cannot be administered oral medication can be problematic. OBJECTIVES To evaluate the efficacy of esomeprazole sodium administered intravenously on gastric juice pH and gastric ulcer scores in horses. ANIMALS Twelve adult female Quarter Horses. METHODS Esomeprazole sodium (0.5 mg/kg IV) was administered once daily to 8 horses (treatment group) and saline (5 mL IV) was administered to 4 horses (control group) for 13 consecutive days. Gastroscopy was performed and gastric juice pH and gastric ulcer score were recorded before and 1 hour after the administration of esomeprazole sodium or saline on days 1 and 5, then on day 14, 23 hours after the 13th daily dose of esomeprazole sodium or saline. RESULTS When compared with values before treatment, gastric juice pH was higher in esomeprazole sodium-treated horses after treatment (4.25 ± 2.39 versus 6.43 ± 1.18; P = .002). Also, gastric juice pH was higher (P = .001) in esomeprazole sodium-treated horses compared with saline-treated control horses on day 5 and on day 14 values. Gastric ulcers were seen in 5/12 (43%) horses in the study. CONCLUSIONS AND CLINICAL IMPORTANCE Esomeprazole sodium shows promise for treatment of gastric ulcers in horses with signs of dysphagia, gastric reflux, or other conditions that restrict oral intake of the current Federal Drug Administration-approved omeprazole paste.

Use of a constant rate infusion of insulin for the treatment of hyperglycemic, hypernatremic, hyperosmolar syndrome in an alpaca cria.

CASE DESCRIPTION A 3-day-old 9.5-kg (21-lb) female alpaca cria was examined because of lethargy and anorexia. CLINICAL FINDINGS Physical examination revealed hyperthermia, muscle fasciculations, and tremors of the head. Seizures were also observed, which indicated CNS dysfunction. Hyperosmolar syndrome (HOS) was diagnosed on the basis of hyperglycemia, hypernatremia, azotemia, high plasma osmolarity, and metabolic acidosis. TREATMENT AND OUTCOME A constant rate infusion of regular insulin was administered with hypo-osmolar fluids to treat HOS, and blood glucose and sodium concentrations were successfully lowered. Neurologic deficits resolved with treatment, and the cria was discharged 11 days after admission. CLINICAL RELEVANCE Administration of insulin as a bolus in addition to hypo-osmolar fluids has been advocated in the management of neonatal camelids with HOS. Administration of regular insulin via a constant rate IV infusion was used to successfully manage a neonatal camelid with HOS. This form of insulin administration may allow more control of glucose kinetics in these patients.

mRNA expression of canine ATP10C, a P4-type ATPase, is positively associated with body condition score

Mouse and human Atp10c genes are strong candidates for changes in bodyweight and glucose homeostasis. Using comparative genomic analysis, a novel canine P4-type ATPase, ATP10C, was identified. Expression of ATP10C was compared between sex-matched lean (body condition score, BCS<8; n=7) and obese (BCS⩾8, n=8) client-owned dogs of comparable ages. Canine ATP10C is highly expressed in visceral and subcutaneous fat at approximately 3-fold levels compared to the omental adipose depot. There was a 5-fold significant increase (P<0.0001) in mRNA expression of ATP10C in dogs with a BCS⩾8.

Pharmacokinetics of chloramphenicol base after oral administration in adult horses

OBJECTIVE To determine the pharmacokinetics of chloramphenicol base after PO administration at a dose of SO mg/kg (22.7 mg/lb) in adult horses from which food was not withheld. DESIGN Prospective crossover study. ANIMALS 5 adult mares. PROCEDURES Chloramphenicol base (SO mg/kg) was administered PO to each horse, and blood samples were collected prior to administration (0 minutes) and at 5, 10, 15, and 30 minutes and 1, 2, 4, 8, and 12 hours thereafter. Following a washout period, chloramphenicol sodium succinate (25 mg/kg [11.4 mg/lb]) was administered IV to each horse, and blood samples were collected prior to administration (0 minutes) and at 3, 5, 10, 15, 30, and 45 minutes and 1, 2, 4, and 8 hours thereafter. RESULTS In horses, plasma half-life, volume of distribution at steady state, clearance, and area under the plasma concentration-time curve for chloramphenicol after IV administration ranged from 0.65 to 1.20 hours, 0.51 to 0.78 L/kg, 0.78 to 1.22 L/h/kg, and 20.5 to 32.1 h·μg/mL, respectively. The elimination half-life, time to maximum plasma concentration, maximum plasma concentration, and area under the plasma concentration-time curve after PO administration ranged from 1.7 to 7.4 hours, 0.25 to 2.00 hours, 1.52 to 5.45 μg/mL, and 10.3 to 21.6 h·μg/mL, respectively. Mean ± SD chloramphenicol bioavailability was 28 ± 10% and terminal half-life was 2.85 ± 1.32 hours following PO administration. CONCLUSIONS AND CLINICAL RELEVANCE Given that the maximum plasma chloramphenicol concentration in this study was lower than previously reported values, it is recommended to determine the drugs MIC for target bacteria before administration of chloramphenicol in adult horses.