A survey study on the availability of anaesthetic breathing systems and their use in dogs weighing 5-10 kg.

Objective: To investigate which breathing systems are available and why they are selected in dogs weighing 5-10 kg.

Study Design: Anonymous online voluntary open survey.

Methods: An online survey, designed following CHERRIES guidelines, was advertised through the American College of Veterinary Anesthesiologists - List, Association of Veterinary Anaesthesia and European College of Veterinary Anaesthesia and Analgesia (February-March 2022). A convenience sample was taken.

Results: Of the 256 responses received, 138 were completed. This included (n responses received) veterinarians (107) and veterinary nurses or technicians (29) actively involved in the anaesthesia of dogs. The most prevalent breathing systems available to respondents were circle (99%), coaxial Bain (79%) and modified Ayre's T-piece (with adjustable pressure limiting valve) (72%). When recommending a dog weight range suitable for the use with these systems, respondents advised a median (interquartile range) from 5 (3-10) to 100 (100-100), 3 (0-8) to 20 (10-33) and 0 (0-0) to 10 (7-10) kg, respectively. Respondents agreed or strongly agreed that important factors in selecting a breathing system were the fresh gas flow requirement (92%), dog weight (91%), resistance (83%) and environmental pollution (79%). In clinical scenarios based on 5-10 kg dogs, the circle system was chosen by 58% for a thin and 77% for a keel-chested versus 44% for an obese and 66% for a barrel-chested dog, respectively.

Conclusions And Clinical Relevance: The circle system is the most commonly available breathing system. The minimum weight limit used for the circle system is less than that reported by previous surveys. Several factors influence the choice of breathing system other than dog weight.