Animals – Skin lumps and bumps

Many cats and dogs develop changes in or under the skin that result in alterations to the skin appearance or texture. There are many reasons for skin changes, and it is a good idea to get these changes checked out by your local veterinary professional. When damaged by trauma the skin often swells with inflammation, which is typically red and painful and may develop secondary bacterial infections. These secondary infections are often dealt with effectively by the animal’s immune system or may need help from medications such as antiseptic creams or washes and antibiotics.

There are many sebaceous or sweat glands associated with the skin, which can create other problems. These sebaceous glands may produce very watery type secretions such as sweat, or oily secretions such as ear wax. Most people will have noticed these oily secretions if they have not washed their hair for a few days, and most dog owners have a good appreciation of oily sebaceous glands. These glands have ducts or tubes leading to the surface of the skin, and occasionally these ducts become blocked. The glands continue to produce their secretions, which develop into cysts. These cysts may be a few millimetres or even several centimetres in diameter.

The nastier side of skin changes may be due to abnormal growths or tumours. People associate tumours with cancer and death, but most tumours are benign. Benign tumours are cells which grow abnormally but do no additional harm. When we get a cut in our skin, our body understands the abnormality and increases its growth to fix the defect. Once the cut is healed, the cells stop growing when they receive a ‘stop signal’. The cells then return to their normal state. However, tumour cells ignore the stop signal and just keep growing.

Malignant tumour cells or cancers are cells which either aggressively grow out into surrounding tissue. Alternatively, they break away from their original location and travel via the blood or lymphatic systems around the body. They often settle in small blood vessels and start growing in their new location. These malignant cells may interfere with the function of the tissue where they start growing abnormally.

As a rough rule, malignant tumours tend to grow quickly, resulting in dramatic changes, while benign tumours grow slowly. After initial veterinary assessment, we often follow the changes in lumps over time, measuring their progress. Frequently, it is useful to use a body part, such as the width of a specific fingernail, as a simple measuring device and record the findings and the date. With the advent of mobile phone cameras, good historical recording can be achieved easily. It is often amazing how useful an accurate record can be compared to your memory. 

Stephen McAulay, CEO and head vet, Wellsford Vet Clinic
www.vetsonline.co.nz/wellsfordvet