Early Heart Disease Signs in Dogs,
Plus How to Count the Breathing Rate
Heart disease is very common in senior small dogs, and nearly invisible at the start. But there's one powerful early signal an owner can catch at home: the breathing rate during sleep. Learning to count it takes 15 seconds, and those 15 seconds buy the golden window of heart-disease management.
The early signals: dry coughing at night and dawn, tiring easily on walks, and a rising resting breathing rate. The key metric, sleeping breathing rate, is safe under 30 breaths per minute: count one rise-and-fall of the chest as one breath for 15 seconds, multiply by 4. Repeated nights over 30, or drift toward 40, calls for a cardiac workup: and for small breeds, senior checkups should include heart auscultation, with ultrasound as indicated.
The early-signal checklist
| Signal | What | Note |
|---|---|---|
| Sleeping breathing rate | Repeatedly 30+/minute | The most reliable home metric |
| Cough | Dry, at night, dawn, on excitement | Needs distinguishing from tracheal |
| Exercise capacity | Sitting down mid-walk, easy panting | Distinguish from summer heat |
| Auscultation finding | Murmur noted at a checkup | The start of surveillance |
| Progression signs | Tongue color change, fainting, swollen belly | Clinic immediately |
Count the breathing tonight
The method is simple. With your dog deeply asleep (calm slumber, not the twitchy dreaming kind), count each rise-and-fall of the chest or belly as one breath for 15 seconds and multiply by 4: that's breaths per minute. I count my dog Gureum's now and then as she sleeps beside me and jot it down (it means "cloud" in Korean), and the accumulation has produced HER normal. In heart management that baseline is gold: the same reading of 32 means different things in a dog whose usual is 18 versus one whose usual is 28. A few measurements taken in health: that's the whole starting investment.
If you've been told there's a murmur
Hearing "there's a heart murmur" at a checkup lands like a stone. But a murmur finding is not a sentence: it's the start of surveillance. Plenty of dogs live symptom-free for years with one; the crux is checking progression on schedule. Typically an ultrasound stages the condition, and the stage sets the plan: watchful waiting, or a medication start date. And even when medication begins, the clinical experience is that modern cardiac drugs meaningfully extend both quality and length of life: this is a disease where early detection pays exceptionally well.
A sleeping video becomes your cardiologist's eyes
The sleeping breathing rate lives in 15 seconds of chest-rise footage. Post it to kkeung and it keeps its date: at the exam you can show exactly when and how they were breathing. It beats any verbal description.
Save a video of your dog →Cardiac emergencies: move, don't watch
These signals mean transport, not observation: purple or pale tongue and gums; open-mouthed labored breathing with the neck extended; a sleeping rate holding above 40; collapsing and recovering (syncope); a filling belly with fading appetite. Heart-failure progression or pulmonary edema may be underway: at night, that means the 24-hour ER. If your dog carries a cardiac diagnosis, share this list with the whole family, so the judgment doesn't wobble on the emergency night.
Daily rules for the cardiac dog
Post-diagnosis life management matters too. Medication on time, never skipped (this one leads the list). Sodium control: salty treats and human food blocked. Weight held in range. And exercise: adjusted, not abolished: short, regular walks within the clinic's allowance are often actively recommended. Avoid summer heat and high-excitement situations. And keep every recheck date even when they look great: cardiac drugs are tuned dose by dose to the current state, and looking fine is never a reason to skip the tuning.
Frequently asked questions
How do I tell a cardiac cough from a tracheal one?
Which breeds are vulnerable to heart disease?
Does the heart ultrasound require a big specialty hospital?
Once heart medication starts, is it for life?
How often should I log the breathing rate?
This article is general information and does not replace a veterinary diagnosis. Talk to your vet about your dog's condition.