No advantage of vapocoolant spray over lidocaine/prilocaine cream for IV catheterisation in dogs and cats, study shows

10 April 2025

There is no difference between vapocoolant spray or eutectic lidocaine/prilocaine (EMLA) cream for improving tolerance of intravenous catheter placement in dogs and cats, according to new research.

Topical anaesthetics are commonly used to reduce discomfort and pain caused by venepuncture for intravenous catheter placement, but there has been no research to date to compare the effects of vapocoolant spray versus eutectic lidocaine/prilocaine (EMLA) cream on the tolerance of intravenous catheterisation in small animals.

Conducted by researchers from the Royal Veterinary College and published in the Journal of Small Animal Practice, a new study assessed 83 dogs and 18 cats requiring intravenous catheterisation for either blood donation collection or as oncology patients. Patients were randomly assigned to receive either EMLA cream or a swab saturated with vapocoolant spray applied before catheterisation, and their reactions were assessed during initial restraint, limb handling, swab application and skin puncture.

Overall, there was no significant difference between vapocoolant spray and EMLA cream, and neither method appeared better at improving patient tolerance of intravenous catheter placement.

Vapocoolant spray was less effective than EMLA cream in reducing adverse reactions to skin puncture during catheterisation in cats, suggesting that EMLA may be preferable for feline patients. Dogs that received vapocoolant spray showed a greater adverse response during swab application compared to those receiving EMLA, possibly due to the coldness of the swab. Success of intravenous catheter placement was identical for both anaesthetics.

Dr Richie Trinder, lead author of the study, commented “The study is the first of its kind comparing vapocoolant spray and EMLA, and suggests in this context that the use of vapocoolant spray provides a similar degree of relief as EMLA, but with the added advantage of being instantaneous, instead of needing to wait the recommended 60 minutes for EMLA.”