Vol. 9, Issue 7 (2020)

Author(s):
S Vigneshwaran, S Senthilkumar, S Dharmaceelan and P Mekala

Abstract:
Abdominal disorders requiring surgical interventions in pregnant cattle warrant safe, reliable and effective anaesthesia. Dexmedetomidine, a newer alpha 2 agonist with high affinity for alpha 2a receptors do not interfere with pregnancy compared to other conventional alpha 2 agonists. The study was designed to evolve pregnancy safe general anaesthetic protocol for cattle. Ten pregnant cattle presented to Veterinary Clinical Complex, Veterinary College and Research Institute, Namakkal requiring major abdominal surgical interventions were selected for the study. Detailed clinical examination incorporating ultrasonography and/or radiography was carried out in all the animals. Surgical interventions were planned based on the diagnosis which revealed intussusception in four cattle, caecal dilation in three animals, DH in two cattle and umbilical hernia in one animal. Preanaesthetic evaluation of all the animals was carried out and stabilization of the patient was done. Dexmedetomidine and butorphanol at the dose rate of 1 microgram per kg and 0.02 mg per kg body weight, respectively were administered intravenously as a premedicant. Induction of anaesthesia was achieved with “double drip” five minutes following premedication. Orotracheal intubation was carried out to have a secure leak-free airway and anaesthesia was maintained with isoflurane. Physiological, cardiopulmonary, anaesthetic and haematobiochemical parameters were studied at periodical interval to ensure safe anaesthesia. Saturation of peripheral oxygen, end tidal CO₂, ECG, end tidal isoflurane, pulse rate, respiratory rate and tidal volume were monitored throughout the anaesthetic period. Surgical interventions selected were performed as per standard surgical technique. Dexmedetomidine and butorphanol premedication provided adequate sedation and facilitated smooth induction. Double drip administration did not cause significant cardiopulmonary depression and facilitated orotracheal intubation. The fresh gas flow rate and vapourizer setting during maintenance was found to be appropriate to maintain surgical plane of anaesthesia. The anaesthetic protocol employed did not produce significant life threatening depression on physiological and cardiopulmonary parameters. The anaesthetic recovery was found to be spontaneous, smooth and struggle-free. The haematobiochemical study did not show any adverse effect on hepatic and renal function. Based on the Fresh Gas Flow rate and vapourizer setting employed, the economics of the anaesthetic protocol was calculated and found affordable. Post anaesthetic follow-up revealed maintenance of pregnancy indicating that the protocol employed was safe in pregnant cattle.