What it is
Chyle is the milky fluid that carries fat absorbed from food through the lymph vessels towards the blood. In a healthy dog it flows through a large duct in the chest. When that flow is disturbed, chyle seeps into the space around the lungs and builds up there, leaving the lungs less and less room to fill with air.
It can arise on its own or follow other problems in the chest, such as heart disease, a tumour or an injury; sometimes no cause is found. The fluid gathers slowly, so at first a dog may seem only quieter and less keen on walks before its breathing visibly changes.
A dog with chylothorax needs calm and rest. Keep it cool, avoid hard play and excitement, and watch how it breathes while it sleeps: a resting dog's chest should rise and fall easily and slowly.
Signs you may notice
- Fast, laboured breathing
- Breathes with the belly
- Coughing
- Tires quickly
- Reluctant to lie down
- Pale or bluish gums
The dog breathes fast and with effort, may cough, tires more quickly and is reluctant to move. If you see that your dog is struggling to breathe, don't wait: take it to a vet right away.
When to see a vet
A dog that is struggling to breathe, or whose gums look pale or blue, needs a vet immediately. Faster breathing than normal while lying calmly is worth a vet visit the same day.
This is general information, not veterinary advice. For your own dog's health, tests and treatment, see a vet.