Nasal discharge in pets

What It Is

Nasal discharge is any fluid coming from one or both nostrils, ranging from thin and clear to thick, coloured, or blood-tinged. Clear discharge often reflects mild irritation or the early stage of an infection, while thick yellow or green discharge usually means bacterial involvement has set in. One-sided discharge is a useful clue, since it often points to something local such as a foreign object or a tooth root problem rather than a whole-body illness.

Common Causes

Upper respiratory infections are the leading cause in cats and are especially common in kittens and shelter cats. Dogs more often get nasal discharge from foreign material like grass awns lodged up the nose, dental disease affecting a tooth root near the nasal cavity, or nasal tumours in older dogs. Fungal infections cause persistent, often one-sided discharge in both species. Allergies and irritant exposure, such as smoke or strong cleaning products, cause milder, usually clear discharge from both nostrils. Horses can develop nasal discharge from strangles or other respiratory infections.

When It Is an Emergency

Heavy bleeding from the nose, discharge paired with facial swelling or sudden difficulty breathing, or a pet that also seems distressed and cannot settle needs same-day veterinary attention. A single sneeze with a small amount of clear discharge in an otherwise well pet is not urgent. Persistent, worsening, or foul-smelling discharge, or any nosebleed that will not stop within a few minutes, should be seen promptly.

What the Vet Will Do

The vet examines the nose, mouth, and face, checking teeth closely since dental disease is an easily missed cause. Imaging such as X-rays or a CT scan can reveal a tumour, foreign object, or fungal infection, particularly for one-sided or long-standing cases. A swab or sample may be sent for infection testing, and in some cases the vet passes a small scope into the nasal passage to look directly at the tissue and remove anything lodged there.

Home Care and Prevention

Gently wiping away discharge and keeping the nostrils clear helps a pet breathe and eat more comfortably during a mild infection. Steam from a bathroom shower can loosen thick mucus in cats with upper respiratory infections. Vaccination reduces the risk of the most common infectious causes, and prompt dental care in older dogs lowers the chance of tooth-related nasal problems developing later.