Effects of peripheral active warming and passive insulation on core body temperature during feline ovariohysterectomy: a multi-arm randomized clinical trial.

OBJECTIVES: Hypothermia is a common complication of anesthesia, particularly in cats. Some veterinarians insulate the extremities of cats as a preventive measure, and there is evidence that heating the extremities of dogs decreases the rate of heat loss from the core. This study investigated whether active warming or passive insulation of the extremities of cats resulted in a slower decrease in rectal temperature during anesthesia. METHODS: Female cats were assigned via block randomization to passive (cotton toddler socks), active (heated toddler socks) or control group (uncovered extremities). Rectal temperature was monitored every 5 mins from induction through return to trap/carrier (final temperature). Multivariable linear regression models were used to compare temperature (rate change and final) between groups. RESULTS: There were 164 cats with 1757 temperature readings. Mean total duration of anesthesia was 53 ± 13 mins. The temperature of all groups decreased linearly over time (all P <0.0001), with the rates of temperature decrease being -0.039°F/min (95% confidence interval [CI] -0.043 to -0.035)/-0.022°C (95% CI -0.024 to -0.019), -0.039°F/min (95% CI -0.042 to -0.035)/-0.022°C (95% CI -0.023 to -0.019) and -0.029°F/min (95% CI -0.032 to -0.025)/-0.016°C (95% CI -0.018 to -0.014) for the control, passive and active groups, respectively. The control, passive and active groups had median final temperatures of 98.4°F (interquartile range [IQR] 97.6-99.4)/36.9°C (IQR 36.4-37.4), 98.0°F (IQR 97.2-98.7)/36.7°C (IQR 36.2-37.1) and 99.1°F (IQR 97.7-100.0)/37.3°C (IQR 36.5-37.8), respectively. After controlling for weight, postinduction temperature and duration of anesthesia, and as compared with controls, the final temperature of the active group was predicted to be 0.54°F (95% CI 0.03-1.01)/0.3°C (95% CI 0.02-0.56) greater (P = 0.023), while the passive group was not significantly different (P = 0.130). CONCLUSIONS AND RELEVANCE: The rate of rectal temperature decrease was significantly slower for the active group compared with the other groups. Although the cumulative difference in final temperature reading was modest, superior materials might enhance performance. Cotton toddler socks alone did not slow the rate of temperature decrease.

Ear-tipping practices for identification of cats sterilized in trap-neuter-return programs in the USA.

OBJECTIVES: Ear-tipping practices and the meaning of the ear tip in trap-neuter-return (TNR) programs have not been well documented. The purpose of this study was to report the frequency of common ear-tipping practices in the USA, to identify the most effective methods and to establish a foundation for ear-tipping practice standards. METHODS: An anonymous 24-question survey was advertised from 4 to 20 October 2021 to individuals who participate in TNR programs that routinely perform ear tipping. RESULTS: There were 526 survey responses from individuals who participate in TNR programs, of whom 410 completed the survey. For ear-tip meaning, nearly 100% of respondents indicated that an ear tip meant that a cat had been sterilized. Several respondents answered that it also indicated rabies vaccination or socialization status, with 92 (22%) selecting both, 79 (19%) selecting rabies only and 50 (12%) selecting unsocial only. The majority of respondents tipped the left ear (81%), used a visual estimate to determine the cut (92%) and described the ideal silhouette as straight across (92%). The median percentage of cats where ear tips bled after initial hemostasis was 5% (interquartile range [IQR] 2-10), and the median percentage of negative feedback regarding the ear tip was 1% (IQR 0-5). In terms of weighted rank order, the most common feedback was that too much ear tip was removed (5.5), followed by a cat being ear tipped in error (4.7), persistent bleeding (4.2) and not enough ear tip being removed (4.2). Responses revealed heterogeneity regarding technique for both excision and hemostasis, as well as personnel performing the procedure. There were no significant associations between techniques and bleeding or negative feedback. CONCLUSIONS AND RELEVANCE: There is variation in the methods for performing an ear tip, as well as what an ear tip signifies. Standards for this procedure would be helpful.