A Simple 60-Second Check Could Improve Outcomes for Cats with HCM

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in domestic cats, affecting about one in seven and is the leading cause of death in cats over nine years old. Despite its prevalence, HCM is difficult to detect early because many cats show no symptoms until they develop severe conditions like congestive heart failure (CHF), arterial thromboembolism, or sudden cardiac death. Traditionally, veterinarians have relied on periodic check-ups and echocardiography for diagnosis, but a simple home-based tool-sleeping respiratory rate (SRR) monitoring-can now help detect early signs of deterioration.

## Why SRR Monitoring Matters

A healthy cat’s SRR is typically below 30 breaths per minute at home. Cats with subclinical heart disease, including HCM, usually maintain stable values below this threshold. However, when SRR begins to rise persistently, it may indicate developing pulmonary edema or pleural effusion before clinical signs appear. Unlike in-clinic measurements, which can be elevated due to stress, SRR taken while a cat is genuinely asleep provides a more accurate baseline of its cardiopulmonary function.

This approach has been successfully used in dogs with preclinical heart disease, where rising respiratory rates have signaled impending congestive heart failure days before overt symptoms. The same principle applies to cats, allowing owners to identify potential issues early and seek veterinary care before an emergency arises.

## How to Integrate SRR Monitoring into Practice

Introducing SRR monitoring should be done in stages. At the initial diagnosis, veterinarians should briefly mention the concept to clients, who may still be processing the news. Detailed instructions should follow at a later visit. Teaching the technique takes about five minutes and involves counting the cat’s breaths while it is deeply asleep-not just resting with closed eyes or purring, as these can alter breathing patterns.

Owners should record two to three measurements per week for the first few weeks to establish a baseline. While the general threshold is 30 breaths per minute, individual cats may have lower or higher normal rates. A persistent SRR above 30 or a 20% increase from the cat’s baseline warrants veterinary attention. However, a single elevated reading is not an emergency, as it could be due to light sleep or environmental factors.

## The Broader Impact of SRR Monitoring

Beyond its clinical benefits, SRR monitoring strengthens the bond between owners and veterinary teams. An HCM diagnosis can leave owners feeling helpless, but this simple tool gives them an active role in their cat’s care. Regular SRR data shared with veterinarians can inform treatment decisions, such as adjusting medications or scheduling earlier follow-ups, without requiring an in-person visit for every concern.

The recent conditional approval of Felycin-CA1 (sirolimus delayed-release tablets), the first disease-modifying drug for HCM, further highlights the importance of home monitoring. As more therapeutic options become available, consistent follow-up and data collection will be crucial for assessing treatment effectiveness. SRR monitoring is a cost-free, low-risk practice that can significantly improve outcomes for cats with HCM.

## Breeds at Higher Risk

Certain cat breeds, such as Maine coons, ragdolls, British shorthairs, Persians, and Sphynxes, have a documented predisposition to HCM. Owners of these breeds should be encouraged to incorporate SRR monitoring into their routine wellness care, even before a formal diagnosis, to detect early signs of cardiac issues.

By teaching owners this simple 60-second check, veterinarians can empower them to take an active role in their cat’s health, leading to better long-term outcomes for feline HCM patients.