Content continues after advertisement

Methadone Versus Buprenorphine for Ovariohysterectomy Analgesia in Cats

Tamara Grubb, DVM, PhD, DACVAA, Washington State University

Sign in to Print/View PDF

In the Literature

Shaw M, Yates D, Hunt J, Murrell J. Comparison between methadone and buprenorphine within the QUAD protocol for perioperative analgesia in cats undergoing ovariohysterectomy. J Feline Med Surg. 2019;21(8):723-731.


Methadone, a full opioid μ-receptor agonist, is expected to provide more profound analgesia as compared with buprenorphine, a partial opioid μ-receptor agonist.1 However, this has been difficult to prove, especially in cats, a species known to hide pain.2

In this clinical study* of cats undergoing ovariohysterectomy (OHE), the authors used a multimodal protocol of buprenorphine with medetomidine, ketamine, and diazepam combined and administered IM (ie, QUAD protocol) or the same protocol using methadone instead of buprenorphine. Administration of meloxicam was reserved until after completion of surgery and pain assessments. Sixty cats were included in each group, and multiple methods were used to assess both pain and sedation.

Cats receiving methadone were found to have lower pain scores than cats receiving buprenorphine, with a greater percentage of cats in the buprenorphine group requiring rescue analgesia. This difference in pain scores was identified with one pain scoring system (ie, the Glasgow Composite Measure Pain Scale) but not with pain assessments using the dynamic interactive visual analogue scale and mechanical nociceptive threshold testing. Hyperalgesia, as measured by mechanical nociceptive threshold testing, developed in every cat; this is a common sequela of tissue injury and is mediated, in large part, by inflammation.


Key pearls to put into practice:


Although commonly referred to as a routine surgery, OHE is not routine for the patient and can be painful.



In this study, despite a robust multimodal analgesia protocol, a significant number of cats needed rescue analgesia in recovery. A validated pain scoring system should be used to assess the pain level of all postsurgical patients, including those undergoing OHE.


The Glasgow Composite Measure Pain Scale is validated to indicate pain in cats, allows for reduced assessor variability by using defined behaviors weighted by severity, and provides intervention guidelines (see Suggested Reading).3,4 The scale is easy to implement and should be strongly considered as an essential tool for pain assessment in cats.


Methadone is a more potent analgesic for OHE pain than buprenorphine. Although methadone is expensive in the United States, feline doses are unlikely to be cost-prohibitive, and the investment preoperatively may help decrease costs by decreasing the need for rescue analgesia and further drug administrations.


Although hyperalgesia occurred in this study despite a robust protocol, administration of NSAIDs early in the pain process as appropriate for the patient may help decrease the occurrence of hyperalgesia.

*Study funded by Dechra Animal Health


For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Clinician's Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.


Clinician's Brief:
The Podcast

Listen as host Beckie Mossor, RVT, talks with the authors of your favorite Clinician’s Brief articles. Dig deeper and explore the conversations behind the content here.
Clinician's Brief provides relevant diagnostic and treatment information for small animal practitioners. It has been ranked the #1 most essential publication by small animal veterinarians for 9 years.*

*2007-2017 PERQ and Essential Media Studies

© Educational Concepts, L.L.C. dba Brief Media ™ All Rights Reserved. Privacy Policy (Updated 05/08/2018) Terms of Use (Updated 05/08/2018)