Liz Bode

Hi everyone,

Ahead of Thursday’s journal club (accessed by the link Scott added above), I will be covering these papers, both open access through JVIM.

Hope to see you there 🙂

Liz

Use of clinical exam etc to identify HCM in cats
MINE2 Score

Sorry this took so long to reply too, I was waiting for info from Oscar as it was beyond my expertise 🙂

Hi Julia,

Great question – it’s a really interesting point and one that’s a bit controversial taking into account how we’re usually taught to be cautious with alpha-2s in cardiac patients.

What I meant is that the effects of dexmedetomidine (and medetomidine as well) are very dose-dependent. At “normal” doses or when given as a bolus, you get the classic picture – peripheral vasoconstriction, reflex bradycardia, and a marked reduction in cardiac output. That is obviously not ideal in many cardiac cases.

However, if you use very low doses as a CRI, you could avoid that plasma peak increase and mainly get the central effects (sympatholysis) without much peripheral vasoconstriction. In practice, that means less catecholamine release, less tachycardia (and bradycardia), reduced myocardial oxygen demand, and generally smoother haemodynamics. That’s where the idea of “cardioprotection” comes from.

In terms of when to use it, I usually think about relatively stable cardiac patients (for example compensated MMVD) where tachycardia or stress responses could be contradictory. It’s not something I would use for in unstable patients. I’d usually start the CRI after induction, once things are stable, and use it as part of maintenance to help with surgical stimulation and reduce inhalant requirements.

For dosing, a typical dexmedetomidine CRI would be around 0.25–1 µg/kg/hour, starting at the lower end and titrating to effect. The aim is trying to remove its sympathetic tone if that makes sense. If dexmedetomidine is not available, medetomidine can be used doubling the dose.

So overall, it’s less about using alpha-2s as “sedatives” and more about using them as a very fine-tuned way of controlling sympathetic tone.

Hope that helps a bit – it’s definitely one of those areas where small dose titration make a big difference!

Thank you

Oscar

Replying to scott@vtx-cpd.com 30/03/2026 - 00:31

Our anaesthetists would use dexmedetomidine (or other alpha-2) in cats with HCM, the main reason being is that HCM is a disease of diastolic function and systolic function is often preserved (unless end-stage), so the alpha-2s will have limited adverse effects on cats. They usually use a low dose (I am sure Oscar discussed this in his webinar), together with an opioid. Cats also less commonly have mitral regurgitation, which would be another contra-indication to using this class of drug (they increase afterload and so can worsen regurgitant fraction through the mitral valve).

Hi Scott,

This is interesting, thanks for posting.

Monitors like this have been around in people for years, they are often used as part of pacemaker technology and are used for a similar reason; to alert clinicians when early congestion might be present. Their use in dogs and cats has been limited by the fact that they were designed for human chests, measuring changes in impedance with respiration, but had never been validated in dogs before. They were known to be inaccurate in dogs because of panting and movement issues. It is interesting that this collar doesn’t appear to work via impedance (not that I could see from their website at least), and good that it records resting/ sleeping breathing rates. It is a clever subscription service for the worried owner I guess! My feeling is that an owner that invests in such technology would be the more motivated owner regardless, and so might not be a great use of money in terms of they would then be more likely to monitor RRR anyway!

Will be interesting to see take up!

Liz

Replying to Julia Biernat 20/02/2026 - 12:31

No problem at all!

Yes, it is always a good one to warn owners about. I always say that some ‘idiopathic’ cases will be mesothelioma in the end and we do not have a good way of identifying which cases have it and which don’t!