If your cat is struggling to breathe, breathing with an open mouth, collapsing or suddenly unable to use a limb, contact an emergency vet immediately. Do not wait to take measurements.
Some cats with heart disease have no outward symptoms. When changes appear, they may resemble other illnesses. Observations help your vet decide what to investigate; they cannot confirm or exclude heart disease at home.
Changes to report
Contact your vet about an unexplained increase in resting breathing rate, reduced appetite, unusual tiredness or reduced activity. Note when changes began and whether they are worsening. Do not assume that a cat becoming less active is simply getting older.
Rapid or laboured breathing and sudden paralysis can occur with serious cardiac complications. Cornell’s cardiomyopathy guide explains these warning signs. They require immediate assessment, whatever their cause.
Do not wait for a particular symptom
A checklist is not a diagnostic test. A cat does not need to show every sign before needing help, and appearing comfortable does not prove that the heart is healthy. If you are uncertain about a breathing change, phone your veterinary practice for triage.
Hiding, reluctance to be handled and changes in resting posture also deserve attention when new or persistent, but do not identify a heart problem by themselves. Describe what you see rather than choosing a diagnosis.
Making observations useful
Keep a brief record of appetite, activity and changes from your cat’s usual routine. If your vet recommends it, learn how to count sleeping breaths and agree a contact threshold. A video may help explain an intermittent change only if it can be taken without distress or delaying care.
Screening and follow-up
Discuss examination findings, breed and family history with your vet. They can recommend whether further testing is appropriate. Our heart screening guide explains questions to ask about an echocardiogram.
General owner information. Seek veterinary advice for changes in your cat’s health.
