Ask the Expert: Solving Eye and Nose Mucous Mystery

Your Pet Question:

My 18-year-old cat gets black mucous around her eyes and nose from time to time. What causes this?

Fran Teskey, Rocky Mountain House, Alberta

The Expert Says:

Most dogs and cats will have a certain amount of discharge from their eyes and sometimes at the nostrils as well. Your cat constantly produces tears to keep its eyes moist. The tears have two components to them: a watery component to provide moisture, and an oily or lipid component to provide protection and slow evaporation of the liquid. The oily component often contains pigments. Once the liquid in the tears evaporates, the oily, pigmented portion – the “mucous” you describe – can be left behind. The tears have a natural tendency to run towards the inside corner of the eye, so this is where most of the discharge is found. There are also tiny ducts found at the inside corner of the eye which drain some of the tears into the nasal cavity. These tears can eventually find their way to the nostril, and again leave mucous there. What is more important than what causes this mucous is how much there is and what color it comes out! If there is copious amounts of discharge, or if the discharge looks bloody, greenish, or yellowish, then there may be a serious problem that your vet needs to examine to ensure your cat is not sick.

Dr. Jay Thrush, DVM, is the owner of Brandon Hills Veterinary Clinic in Brandon, Manitoba.