April 7th, 2014
The one good thing about skin problems in older pets is that they don’t have to worry about wrinkles like we do. I guess that is one advantage to being covered in fur! What they do have to worry about is thinning hair, endocrine disease, allergies, tumors, and menagerie of other problems.
As dogs or cats age, there is a decrease in the number of active hair follicles that leads to thinning of the hair coat. They also experience a decrease in pigment produced leading to graying of the hair around the muzzle. Their nails become longer, malformed, and more brittle so it is important to keep them trimmed so they don’t break. You also may see thickening of the foot pads, pressure point calluses, and nose. Altered oil production and cystic dilation of the sweat glands results in a dry, lack luster hair coat. To help with some of these hair coat issue you can try increased grooming and brushing, less bathing, coat conditioners, topical oils and moisture sprays, and essential fatty acid nutritional supplements.
Endocrine diseases, which are diseases that affect various hormones produced by the body, include hypothyroidism and Cushing’s disease. Hypothyroidism is a decrease in activity of the thyroid gland that will cause premature graying of the muzzle, a thinning and brittle hair coat, and dandruff. Cushing’s disease also affects the skin by causing, thinning of the skin, patterned hair loss that usually starts on the tail (referred to as rat tail) and belly and can progress to the rest of the body. To diagnose both of these diseases you need specialized blood tests performed by your veterinarian.
Skin tumors may start popping up as the years go by. About 35% of the time they are senile warts which are called sebaceous gland tumors. They are benign and can be left alone, surgically removed, frozen off, or removed by topical chemotherapy agents. Other more serious and malignant tumors include melanoma and squamous cell carcinoma. Melanomas are commonly dark in color and can be found anywhere but are usually located at the lip or eye margins or inside the mouth. If your pet has a suspicious growth on the skin it is always a good idea to have it checked out by your veterinarian. Your veterinarian should stick a needle in it and look at the cells under the microscope. You can’t always tell what it is by just looking at it and a serious skin tumor could be misdiagnosed as nothing to worry about.
Food allergies can also appear as your pet ages. This can cause non-seasonal itching, ear infections, paw licking, thinning hair coat, skin infections, and redness. This can be a frustrating problem to diagnose and treat because there are other causes that have to be ruled out as well. The best way to know if your dog has food allergies is to place them on a prescription allergy diet or give them a novel protein diet (duck and potato is one of many examples) for at least 2 months with absolutely no other food, treats, or table scraps and see if the symptoms go away. If they do you can leave them on that diet for the remainder of their life to prevent skin problems from occurring again.
M. H. Archer, DVM