Cardiorespiratory, anaesthetic and recovery effects of morphine combined with medetomidine and alfaxalone in rabbits.

Ten New Zealand White rabbits were used in a crossover experimental study: 200 µg/kg medetomidine and 1 (M1) or 2 mg/kg (M2) morphine were administered intramuscularly. After preoxygenation, anaesthesia was induced with alfaxalone at 10 mg/kg intravenously. The trachea was intubated and 60 per cent oxygen provided. Heart and respiratory rates (HR and RR), direct arterial pressures (APs), arterial pH (pHa), PaO2, PaCO2 and SaO2 were taken at baseline, after premedication and every 10 minutes during the 90 minutes following induction. The times to return the ear pinch, toe pinch and righting reflexes were recorded. Data were analysed using a two-way analysis of variance and a paired samples t test. Compared to baseline values, HR, RR, APs, PaO2 and SaO2 decreased significantly after premedication in both groups. Postinduction apnoea of 20 ± 10 with M1 and 27 ± 18 minutes with M2 was experienced following alfaxalone administration, intermitent positive pressure ventilation was applied until spontaneous breathing efforts appeared. Cardiovascular variables, RR and pHa remained below, and PaCO2 over baseline values during the anaesthetic period. No significant differences were observed in the recovery times. Morphine at 1 or 2 mg/kg combined with medetomidine and alfaxalone in rabbits produced a suitable level of anaesthesia, although profound cardiorespiratory depression was found.

Haematological, blood gas and acid-base values in the Galgo Español (Spanish greyhound).

OBJECTIVES: Haematologic profiles, electrolyte concentrations, blood gas values and acid-base balance have been studied and reported in healthy greyhounds; however, there is only one study published on blood gas values in Galgos Españoles. Because of their purported common origins with greyhounds (same group and class), it was hypothesised that Galgos Españoles also have differences in haematologic values, electrolyte concentrations, blood gas values and acid-base balance compared to other non-sporting breeds. METHODS: Venous blood samples from 30 Galgos Españoles and 20 dogs from different breeds were collected, and complete blood counts, electrolyte concentrations, blood gas values and acid-base balance were measured. RESULTS: From the 24 parameters analysed, 5 had statistically significant differences (P<0·05). Galgos Españoles had higher haematocrit (P<0·001), haemoglobin concentration (P=0·003), erythrocyte count (P=0·016) and pH (P=0·03), and lower platelet count (P=0·005), than those in other-breed dogs. CLINICAL SIGNIFICANCE: These results confirm that significant haematologic differences exist in Galgos Españoles when compared with other dogs, although these differences are not as striking as in greyhounds. Practitioners need to be aware of these breed-specific differences in order to make accurate diagnoses in Galgos Españoles.