Unexpected recovery in anaesthetized badgers - High rectal temperature indicates an increased risk

Journal

Veterinary Anaesthesia and Analgesia, Volume 32, Number 1, January 2005, pp. 48-52(5) - Blackwell Publishing

Authors

Graeme W McLaren; Peter D Thornton; Chris Newman; Christina D Buesching; Sandra E Baker; Fiona Mathews; David W Macdonald from the Wildlife Conservation Research Unit, University of Oxford and Oxford University Veterinary Services.

Abstract

Objective

To identify factors associated with sudden early recovery (SER) from anaesthesia in badgers.

This was an experimental trial involving the use of ninety-three adult wild badgers.

Animals were randomly assigned to receive one of four anaesthetics based on medetomidine (M) ketamine (K) and butorphanol (B) combined in different ratios:

(i) MKB 20:40:80 µg kg^-1;

(ii) MKB 20:40:60 µg kg^-1;

(iii) MKB 20:60:40 µg kg^-1; and

(iv) ketamine alone 0.2 mg kg^-1.

For each animal, induction time was measured and physiological variables (heart rate, respiratory rate and rectal temperature) were recorded at 5-minute intervals during anaesthesia. Cases of SER were recorded and binary logistic regression applied to identify predictive factors.

Results

Fourteen animals (15%) exhibited SER. Rectal temperature was the only variable that was a significant predictor of SER. Animals showing SER had significantly higher rectal temperatures which, in contrast to other cases, did not fall during the first 10 minutes of anaesthesia, which was when most SERs occurred.

Conclusion and clinical relevance

We recommend that:

(i) rectal temperature is closely monitored during wild badger anaesthesia and

(ii) that animals with higher than expected temperatures are treated with additional caution.

Keywords

anaesthesia; animal welfare; badgers; early recovery; temperature

Web site

• http://www.ingentaconnect.com/content/bsc/vaa/2005/00000032/00000001/art00007