Comparison of glycopyrrolate and atropine in ameliorating the adverse effects of imidocarb dipropionate in horses.

REASONS FOR PERFORMING STUDY: Imidocarb, an effective treatment for piroplasmosis, may cause colic and diarrhoea in horses. Atropine and glycopyrrolate are anticholinergics that could reduce the adverse effects of imidocarb. However, atropine and glycopyrrolate inhibit gastrointestinal motility, potentially causing ileus and colic. OBJECTIVES: To compare glycopyrrolate and atropine in ameliorating the adverse effects of imidocarb dipropionate in horses and to determine the effect of combinations of these drugs on the gastrointestinal tract. METHODS: A blinded, randomised, crossover study was performed in 8 healthy horses. Each horse received 0.9% saline i.m and i.v. (CON), and imidocarb 2.4 mg/kg bwt i.m. with one of 3 treatments i.v.: 0.9% saline (IMI), atropine 0.02 mg/kg bwt (IMATROP) and glycopyrrolate 0.0025 mg/kg bwt (IMGLYCO). Clinical data, gastrointestinal motility via borborygmi and frequency of contractions in the duodenum, caecum and right dorsal colon assessed with transabdominal ultrasound, and faecal data were measured. RESULTS: After imidocarb/saline treatment colic and diarrhoea were noted in 3 and 4 horses, respectively, faecal production and defaecation were increased for 3 h and faecal water percentage for 6 h. Colic was noted after atropine treatment in 4 horses, borborygmi and frequency of right dorsal colon contractions were significantly decreased for 2 h 15 min, and faecal production was not significantly different from CON. After glycopyrrolate treatment, colic was seen in one horse, frequency of intestinal contractions and faecal data were not significantly different from CON, and borborygmi was significantly decreased from CON at 1 h 15 min. CONCLUSIONS: Results of this study suggest that glycopyrrolate is superior to atropine in ameliorating the adverse effects of imidocarb. POTENTIAL RELEVANCE: Glycopyrrolate could be administered with imidocarb in horses with piroplasmosis to reduce the adverse effects of imidocarb.

Nuchal crest avulsion fracture in 2 horses: a cause of headshaking.

The medical records of 2 Thoroughbred horses that developed headshaking after blunt trauma to the occipital region are reviewed. The history, signalment, clinical signs, diagnostic methods, diagnosis and treatment were recorded in each case. Both horses displayed headshaking, while one horse repeatedly lifted its upper lip and pawed excessively at the ground. In both horses, diagnostic imaging of the occipital region revealed avulsion fragments of the nuchal crest and a nuchal desmitis in association with hyperfibrinogenaemia. The presence of an avulsion fragment of the nuchal crest with associated nuchal desmitis should be considered in horses presenting with headshaking and may respond favourably to conservative therapy.

After-hours equine emergency admissions at a university referral hospital (1998-2007): causes and interventions.

Medical records of equine after-hours admissions from 1998 to 2007 are reviewed. Data extracted from the medical records included signalment, reason for admission, pre-admission treatment, clinical presentation, procedures performed, final diagnoses, complications occurring in hospital, length of stay and outcome. Eight hundred and twenty after-hours admissions were available of which 75% were classified as emergencies. Most horses originated from Gauteng province (82%), with Thoroughbred, Arabian, and Warmbloods representing 46%, 10% and 7% of horses. Horses had a median age of 7 years and were predominantly male (60%). Gastrointestinal (64%) and musculoskeletal (19%) disorders were the primary reasons for admission. Anti-inflammatories, sedation and antibiotics were given in 51%, 20% and 15% of cases respectively prior to referral. On admission, 23% of horses had surgical intervention. Intravenous catheterisation (64%), rectal examination (61%), nasogastric intubation (56%), abdominocentesis (33%) and ultrasonography (19%) were the procedures performed most frequently. Surgical and medical colics constituted 28% and 27% respectively of the overall diagnoses, while piroplasmosis was diagnosed in 5% of horses. Post-admission complications occurred in <2% of horses. The median length of stay was 4 days (95% CI: 1 to 21 days). Overall survival to discharge was 74%. This study demonstrates that the majority of after-hours equine admissions to a university referral hospital required medical intervention and were mostly due to gastrointestinal disorders. Information obtained from this study can be used in emergency referral planning.

Causes of gastrointestinal colic at an equine referral hospital in South Africa (1998-2007).

The most common causes of gastrointestinal colic at an equine referral hospital in South Africa were determined following retrieval of the medical records of horses admitted during a 10-year study period. The study included 935 horses of which 28% were admitted after hours. Most horses were Thoroughbreds (54%), male (57%), with a mean age of 8.2 years and originated from the Gauteng Province (81%). Heart rate (98%), mucous membrane colour (95%) and auscultation of the abdomen (91%) were the clinical data commonly obtained at admission. Packed cell volume, total serum protein and white cell count were recorded in 78%, 75% and 44% of horses respectively. Transrectal palpation (93%), nasogastric intubation (84%), intravenous catheterisation (74%) and abdominocentesis (53%) were the most frequently performed procedures. Medical intervention was performed in 558 horses (60%). The common causes of medical colic were impactions (39%), tympany (7%) and displacement of the large colon (6%). An exploratory laparotomy was performed in 331 horses (36%). The common causes of surgical colic were displacement (29%), impaction (22%) and small intestinal strangulating lesions (18%). Death occurred in 3% of horses, while euthanasia before medical intervention was performed in 4%. Overall, medical intervention was successful in 93% of horses and 67% in horses managed surgically. In conclusion, 55% of all the equine admissions responded to medical intervention and the recovery rate for horses receiving both medical and surgical intervention was comparable to that reported in other studies.