What it is
Picture a heart whose muscular walls have thinned and lost their spring. Each beat pushes out less blood, so the heart stretches to hold more, and the stretching weakens it further. The body tries to make up for it by holding on to salt and water, and that extra fluid eventually backs up into the lungs or the belly. The stretched muscle can also lose its rhythm, which is why some dogs faint.
The disease can be inherited, is linked to large, deep-chested dogs and tends to appear from middle age. A vet can sometimes pick up changes in the heart before you notice anything at home.
Day to day, you may find your dog choosing shorter walks and lying down more. Counting its breaths while it sleeps is a simple way to notice change: faster sleeping breaths are worth telling your vet about. Let your dog set the pace, and do not push exercise on hot days.
Signs you may notice
- Tires sooner on walks
- Coughs, especially at night
- Fast breathing at rest
- Eats less, loses weight
- Swollen belly
- Fainting or sudden weakness
You may notice the dog tiring sooner, coughing, breathing faster or harder even at rest, eating less, losing weight, or developing a swollen belly. Sudden weakness or fainting is a sign that the dog needs a vet immediately.
When to see a vet
Fainting, sudden collapse or struggling to breathe means a vet is needed immediately. Book a visit if your dog tires sooner, coughs or breathes faster while asleep.
This is general information, not veterinary advice. For your own dog's health, tests and treatment, see a vet.