Preliminary evaluation of hepatitis A virus cell receptor 1/kidney injury molecule 1 in healthy horses treated with phenylbutazone.

OBJECTIVES: To investigate if hepatitis A virus cell receptor 1/kidney injury molecule 1 (HAVCR1/KIM1) in urine is detectable concurrently with increases in serum creatinine concentrations in horses receiving a recommended dose of phenylbutazone (PBZ) for 7 days. DESIGN: Preliminary study. METHODS: Ten clinically healthy horses with normal physical examination and laboratory work were randomly assigned to PBZ or placebo groups (5 each). The PBZ group received PBZ at 4.4 mg/kg mixed with corn syrup orally every 12 hours. The placebo group received corn syrup orally every 12 hours. Both groups were treated for 7 days. Kidney ultrasonography was performed, and venous blood and urine samples were collected prior to commencement and at the end of treatment. Samples from 1 additional healthy horse, 3 horses with acute kidney failure, and 1 horse with chronic kidney failure were also evaluated. RESULTS: None of the 10 horses had detectable HAVCR1/KIM1 in urine at baseline. Serum creatinine concentrations in placebo group did not increase, and HAVCR1/KIM1 was undetectable in urine. At the end of treatment, 3 of 5 horses receiving PBZ developed increases in serum creatinine of >26.5 µmol/L (>0.3 mg/dL), and HAVCR1/KIM1 was detectable in urine, despite normal findings on kidney ultrasonography in all horses. CONCLUSIONS: HAVCR1/KIM1 is detectable in urine and is associated with increases in serum creatinine concentrations of >26.5 µmol/L in horses following treatment with PBZ for 7 consecutive days. Thus, HAVCR1/KIM1 might aid in the early detection of acute kidney injury in horses.

Gentamicin-induced sensorineural auditory loss in healthy adult horses.

BACKGROUND: Irreversible sensorineural auditory loss has been reported in humans treated with aminoglycosides but not in horses. OBJECTIVE: Investigate if auditory loss occurs in horses treated using the recommended IV daily dosage of gentamicin for 7 consecutive days. ANIMALS: Ten healthy adult horses (7-15 years; females and males, 5 each). METHODS: Prospective study. Physical and neurological examinations and renal function tests were performed. Gentamicin sulfate was administered at a dosage of 6.6 mg/kg via the jugular vein on alternating sides for 7 days. Gentamicin peak and trough concentrations were measured. Horses were sedated using detomidine hydrochloride IV to perform brainstem auditory evoked responses (BAER) before the first dose, immediately after the last dose, and 30 days after the last dose. Peaks latencies, amplitudes, and amplitude ratios were recorded. Data from the second and last BAER were compared to results at baseline. Bone conduction was performed to rule out conduction disorders. RESULTS: Seven horses had auditory loss: complete bilateral (N = 1), complete unilateral (N = 2), and partial unilateral (N = 4). Based on physical examination and BAER results, sensorineural auditory loss was suspected. Absent bone conduction ruled out a conduction disorder and further supported sensorineural auditory loss in horses with completely absent BAER. Auditory dysfunction was reversible in 4 of 7 horses. CONCLUSIONS AND CLINICAL IMPORTANCE: Gentamicin at recommended doses may cause sensorineural auditory loss in horses that might be irreversible. Follow-up studies are needed to investigate if other dosing protocols present a similar risk.

Current Operational Model for Veterinary Care in Large Animal Shelters During Disasters.

Standardization of operating guidelines for veterinary care in evacuation and emergency animal shelters is imperative for an organized response and to facilitate treatment and prevention of medical conditions stemming from the effects of a disaster and the associated outcomes of sheltering. Safeguarding animal welfare through creating guidelines should expedite care, assure consistency, and provide appropriate safety measures for animals and veterinary medical providers. Veterinary integration into an incident command system (ICS) and response training allows for proper allocation of roles and responsibilities, as well as coordination of veterinary supplies and personnel. Central components of the operational model include guidelines for animal identification, triage, medical records, medical treatments, and discharge instructions. An outline for communication with disaster response agencies, as well as animal owners, is aimed to inform appropriate conduct. Improving the animal component of disaster response is integral in meeting societal needs and improving animal welfare in the face of a disaster.

Disaster Medicine: Implementation of an animal health database in response to the 2018 California Camp Fire.

OBJECTIVE: To describe an animal health database used to facilitate effective disaster response and retrospective analysis of data concerning animals other than cats and dogs affected by the 2018 California Camp Fire. ANIMALS: Veterinary medical entries (n = 206) for evacuated or rescued animals (151) of various species, including avian, bovine, camelid, caprine, equine, ovine, and porcine species, temporarily housed at the Butte County fairgrounds in Gridley, Calif. PROCEDURES: Case data were collected via a standardized form by volunteers with the University of California-Davis Veterinary Emergency Response Team during triage and treatment of animals brought to the shelter. Collected data were entered into a database. Multiple correspondence analysis was used to evaluate associations among patient species, types and severity of injuries, and behavior. RESULTS: Burns, respiratory disease, gastrointestinal illnesses, and lacerations were the most prevalent illnesses and injuries among the overall shelter population for the first 12 days of the Camp Fire. Ovine patients were more likely to have had respiratory illness than were other species. The most prevalent medical conditions among equine patients were lacerations and gastrointestinal illnesses. Severe burns were most common among porcine, camelid, and avian patients. The temporal distribution of cases suggested the immediate evacuation of equine species and the delayed movement of bovine and avian species to the shelter. CONCLUSIONS AND CLINICAL RELEVANCE: Collection of animal health information through the database allowed assessment of prevalent medical conditions among various farm animals following a wildfire. Adaptation of this database to other disasters could improve emergency response protocols by providing guidance for management of resources and allow retrospective assessment for response improvement.

Comprehensive Report of the Caseload of Donkeys and Mules Presented to a Veterinary Medical Teaching Hospital over a Ten-Year Period.

Comprehensive reports of the caseload of donkeys and mules in veterinary hospitals in the United States are lacking. We compiled the information of the caseload of donkeys and mules at the Veterinary Medical Teaching Hospital at the University of California, Davis for a ten-year period, from 2008 to 2017. The overall equid caseload was 94,147, of which 996 (1.06%) were donkeys and mules. Most of the neonates seen were mules. Most miniature donkeys were between 2 and 10 years of age, and standard donkeys and mules were 10 to 20 years old. The body condition scores were predominantly high, especially in donkeys. Most miniature and standard donkeys resided in sanctuary and rescue farms and their use was not stated. Most mules were used for riding, packing or driving. Medical complaints represented 62% of the total visits and wellness visits represented 38% of total visits. The donkeys and mules in the case population described here received a good standard of veterinary care with regular vaccinations, deworming, routine dental care, and treatment of ailments. Our study is the first report of the life expectancy, use, body condition, preventative health and veterinary medical care of a population of donkeys and mules in the western United States.

Effects of magnesium with or without boron on headshaking behavior in horses with trigeminal-mediated headshaking.

BACKGROUND: Oral administration of magnesium and boron might have a beneficial effect on headshaking behavior in horses. OBJECTIVE: Evaluate the effects of oral magnesium alone or in combination with boron on headshaking behavior in affected horses. ANIMALS: Twelve geldings (6 healthy controls and 6 affected). METHODS: Prospective randomized controlled dietary trial over 42 days in 12 horses (6 horses diagnosed with trigeminal-mediated headshaking and 6 unaffected healthy controls). All horses received a hay diet and were randomized into 3 treatment groups: pelleted feed combination (PF), pelleted feed combination with magnesium (M), and pelleted feed combination with magnesium-boron (MB) with a week washout of hay only between treatments. Headshaking behavior and biochemical blood variables were assessed at baseline (hay only) and then after each week of supplementation. RESULTS: All 3 diet interventions increased blood ionized and total magnesium. Groups M and MB further increased Mg2+ when compared to PF. Horses receiving treatments had a significant reduction in headshaking behavior, as measured by incidence rate ratio (IRR), when compared to unsupplemented hay diet (44% for PF, IRR, 0.558; CI, 0.44, 0.72; P < .001; 52% for M, IRR, 0.476; CI, 0.37, 0.62; P < .001; and 64% for MB, IRR, 0.358; CI, 0.27, 0.48; P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Magnesium in combination with boron had the greatest decrease in headshaking. Oral supplementation with magnesium or magnesium in combination with boron should be considered in horses affected with headshaking.

Effect of a syringe aspiration technique versus a mechanical suction technique and use of N-butylscopolammonium bromide on the quantity and quality of bronchoalveolar lavage fluid samples obtained from horses with the summer pasture endophenotype of equine asthma.

OBJECTIVE To evaluate the effect of 2 bronchoalveolar lavage (BAL) sampling techniques and the use of N-butylscopolammonium bromide (NBB) on the quantity and quality of BAL fluid (BALF) samples obtained from horses with the summer pasture endophenotype of equine asthma. ANIMALS 8 horses with the summer pasture endophenotype of equine asthma. PROCEDURES BAL was performed bilaterally (right and left lung sites) with a flexible videoendoscope passed through the left or right nasal passage. During lavage of the first lung site, a BALF sample was collected by means of either gentle syringe aspiration or mechanical suction with a pressure-regulated wall-mounted suction pump. The endoscope was then maneuvered into the contralateral lung site, and lavage was performed with the alternate fluid retrieval technique. For each horse, BAL was performed bilaterally once with and once without premedication with NBB (21-day interval). The BALF samples retrieved were evaluated for volume, total cell count, differential cell count, RBC count, and total protein concentration. RESULTS Use of syringe aspiration significantly increased total BALF volume (mean volume increase, 40 mL [approx 7.5% yield]) and decreased total RBC count (mean decrease, 142 cells/µL), compared with use of mechanical suction. The BALF nucleated cell count and differential cell count did not differ between BAL procedures. Use of NBB had no effect on BALF retrieval. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that retrieval of BALF by syringe aspiration may increase yield and reduce barotrauma in horses at increased risk of bronchoconstriction and bronchiolar collapse. Further studies to determine the usefulness of NBB and other bronchodilators during BAL procedures in horses are warranted.

Inhalation Therapy in Horses.

This article discusses the benefits and limitations of inhalation therapy in horses. Inhalation drug therapy delivers the drug directly to the airways, thereby achieving maximal drug concentrations at the target site. Inhalation therapy has the additional advantage of decreasing systemic side effects. Inhalation therapy in horses is delivered by the use of nebulizers or pressured metered dose inhalers. It also requires the use of a muzzle or nasal mask in horses. Drugs most commonly delivered through inhalation drug therapy in horses include bronchodilators, antiinflammatories, and antimicrobials.

Temporal clinical exacerbation of summer pasture-associated recurrent airway obstruction and relationship with climate and aeroallergens in horses.

OBJECTIVE: To describe the seasonal pattern of clinical exacerbation of summer pasture-associated recurrent airway obstruction (SPA-RAO) in relation to climate and aeroallergens in horses. ANIMALS: 19 horses with SPA-RAO and 10 nonaffected horses. PROCEDURES: Daily examinations were performed on all horses while they were kept on pasture for 3 years. Onset and progression of clinical exacerbation based on a clinical score of respiratory effort were evaluated in relation to changes in maximum temperature, minimum temperature, mean temperature, maximum dew-point temperature, minimum dew-point temperature, and delta dew-point temperature. Seasonal pattern of clinical exacerbation was evaluated in relation to aeroallergen counts (20 types of fungal spores and 28 types of pollen). RESULTS: Seasonal pattern of clinical exacerbation of SPA-RAO was associated with increases in temperature (heat) and dew-point temperature (humidity), counts of fungal spores, and counts of grass pollen grains. Seasonal pattern of clinical exacerbation paralleled and was associated with increases in counts of specific types of fungal spores, particularly Basidiospore, Nigrospora, and Curvularia spp. CONCLUSIONS AND CLINICAL RELEVANCE: Although a causal relationship could not be determined, the seasonal pattern of clinical exacerbation of SPA-RAO was associated with hot and humid conditions and high environmental counts for fungal spores and grass pollen grains. It is not known yet whether these are aeroallergens that cause clinical exacerbation of the disease.

Immunohistochemical determination of the expression of endothelin receptors in bronchial smooth muscle and epithelium of healthy horses and horses affected by summer pasture-associated obstructive pulmonary disease.

OBJECTIVE: To immunohistochemically determine the expression of endothelin (ET) receptors in bronchial smooth muscle and epithelium of healthy horses and horses affected by summer pasture-associated obstructive pulmonary disease (SPAOPD). SAMPLE POPULATION: Tissue specimens obtained from 8 healthy and 8 SPAOPD-affected horses. PROCEDURE: Horses were examined and assigned to healthy and SPAOPD groups. Horses were then euthanatized, and tissue specimens containing bronchi of approximately 4 to 8 mm in diameter were immediately collected from all lung lobes, fixed in zinc-formalin solution for 12 hours, and embedded in paraffin. Polyclonal primary antibodies against ET-A or ET-B receptors at a dilution of 1:200 and biotinylated IgG secondary antibodies were applied to tissue sections, followed by the addition of an avidin-biotin immunoperoxidase complex. Photographs of the stained slides were digitally recorded and analyzed by use of image analysis software to determine the intensity of staining. Two-way ANOVA was used for statistical analysis. RESULTS: The left diaphragmatic lung lobe of SPAOPD-affected horses had a significantly greater area of bronchial smooth muscle that immunostained for ET-A, compared with that for healthy horses. All lung lobes of SPAOPD-affected horses, except for the right diaphragmatic lobe, had significantly greater staining for ET-B receptors in bronchial smooth muscle, compared with results for healthy horses. CONCLUSIONS AND CLINICAL RELEVANCE: This study revealed overexpression of ET-A and, in particular, ETB receptors in the bronchial smooth muscle of SPAOPD-affected horses, which suggested upregulation of these receptors. These findings improve our understanding of the role of ET-1 in the pathogenesis of SPAOPD.

Abomasal ulceration and abomaso-pleural fistula in an 11-month-old beefmaster bull.

An 11-month-old, beefmaster bull presented with anorexia and signs of respiratory disease. Physical examination, thoracic ultrasonography and radiography, and pleural fluid analysis indicated pericarditis and septic neutrophilic pleuropneumonia. Postmortem findings were abomasal adherence to the diaphragm, a fibrotic fistulous tract connecting the abomasum and pleural cavity, granulomatous abomasitis, granulomatous pericarditis, and fibrinonecrotic pleuritis.