Inflammatory bowel disease (IBD) in horses: a retrospective study exploring the value of different diagnostic approaches.

BACKGROUND: Diagnosing IBD in horses is challenging and requires a multimodal approach, since no conclusive diagnostic test is available. The objectives of this study were to provide an overview of population characteristics, results of applied diagnostic tests, treatment modalities and outcome in a large group of horses thought to have IBD and that were presented to four large equine referral hospitals, and to provide an exploratory investigation of possible associations between results of applied diagnostic tests, applied treatment modalities and outcome. A retrospective case series was performed across four large equine referral hospitals. Seventy-eight horses, thought to have IBD were included. Case history, clinical findings, diagnostic test results including oral glucose tolerance test (OGTT) and enteral biopsies (both duodenal and rectal), applied therapy and outcome were studied. A Chi-Square test was used to identify associations between results of diagnostic tests, treatment and outcome. P-values < 0.05 were considered significant. RESULTS: Lethargy, diarrhoea, recurrent colic and weight loss were recorded in respectively 21,8%; 14,1%; 28,2% and 78,2% of cases. Over 70% of horses thought to have IBD had an abnormal OGTT. Only weight loss was significantly associated with aberrant enteral biopsy results, but not with abnormal OGTT results or low blood total protein. There was no association between an aberrant biopsy result and a disturbed OGTT. There was no association between either OGTT results or enteral biopsy results and a low blood total protein content, presence of gastric ulcer disease or an aberrant endoscopic aspect of the duodenal entrance. CONCLUSIONS: Weight loss is a highly prevalent symptom in IBD suspected horses. Enteral biopsies may be a useful diagnostic aid in the work-up of horses thought to suffer from IBD, however further research is required to demonstrate their true diagnostic value. Until more standardized scientific research is available, one should be careful with the interpretation of enteral biopsy results There is a need for better standardization of enteral biopsy procedures and the histopathological scoring of biopsies.

Cardiopulmonary effects of combined xylazine-guaiphenesin-ketamine infusion and extradural (inter-coccygeal lidocaine) anaesthesia in calves.

OBJECTIVE: To investigate the cardiopulmonary effects of a xylazine-guaiphenesin-ketamine infusion combined with inter-coccygeal extradural (lidocaine) anaesthesia in calves. STUDY DESIGN: Prospective study. ANIMALS: Five Holstein Friesian calves (one steer, four heifers) aged 6 weeks weighing 65.2 +/- 2.7 kg. MATERIALS AND METHODS: Calves were anaesthetized with isoflurane in oxygen for instrumentation. At least 12 hours later, xylazine (0.2 mg kg(-1) i.m.) was given. After 15 minutes, an infusion of xylazine hydrochloride (0.1 mg mL(-1)), guaiphenesin (50 mg mL(-1)) and ketamine (1 mg mL(-1)) (X-G-K) was infused at a rate of 1.1 mL kg(-1) hour-1 i.v. Oxygen (4 L minute(-1)) was delivered by nasotracheal tube 30 minutes later. Inter-coccygeal (Co1-Co2) extradural anaesthesia (lidocaine 2%, 0.18 mL kg(-1)) was administered 30 minutes later. Cardiopulmonary variables were obtained in the unsedated standing calves 10 minutes after xylazine, 15 and 30 minutes after X-G-K without O2, 15 and 30 minutes after X-G-K with O2 and 5, 15, 30, 45 and 60 minutes after extradural anaesthesia. Data were analysed using a repeated measurement analysis of variance including an autoregressive covariance structure of order 1 (correlations at different time intervals). RESULTS: Xylazine caused significant (p<0.05) decreases in heart rate (HR), cardiac output (Qt) and index (CI), stroke volume and stroke index, mean, systolic and diastolic arterial blood pressure (MAP, SAP, DAP), left (LVWSI) and right ventricular stroke work index (RVWSI), mean, systolic and diastolic pulmonary arterial pressure (MPAP, SPAP, DPAP), arterial pH, arterial oxygen tension (PaO2), arterial base excess, arterial HCO3- concentration, arterial saturation, packed cell volume, arterial and venous oxygen content (CaO2, CvO2), O2 consumption and O2 delivery (VO2, DO2). Increases in systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR) were observed. During X-G-K infusion without O2, HR, Qt and CI increased gradually while SVR, PVR and MAP decreased. Left ventricular stroke work index and PaO2 remained constant, while O2 supplementation improved PaO2. Coccygeal extradural anaesthesia had little effect on cardiopulmonary variables. Respiratory rate (f) and PaCO2 significantly increased over the experiment. CONCLUSIONS AND CLINICAL RELEVANCE: Xylazine caused adverse cardiopulmonary effects in calves. Improvement occurred during xylazine-guaiphenesin-ketamine infusion. Cardiac index and arterial blood pressure remained below baseline values while sustained increases in respiration rate and PaCO2 were observed. Inter-coccygeal extradural anaesthesia had only minor effects. Oxygen supplementation proved advantageous during guaiphenesin, ketamine and xylazine infusion in healthy calves in combination with coccygeal extradural anaesthesia induced persistent cardiopulmonary depression.