Us dog lovers know it’s normal for our furry friends to shed hair and sometimes a lot of it!
But if your dog is developing bald spots or their hair is becoming thin, it can be a sign of an underlying problem.
Alopecia is fur loss or absence from a part of the body where it should be present
Hair can either fail to grow at a normal rate or be falling out more quickly than it can grow back. It is a symptom of an underlying problem.
There are many possible reasons for abnormal hair loss. Skin allergies, parasites such as fleas and mites, and hormonal problems are some of the common causes.
It is usually treatable and rarely permanent.
Normal hair shedding (and the amount of hair you need to hoover up!) is based on the natural growth cycles of the hair in the follicles which can vary depending on breed, age, hormones and the time of year. Once a hair grows it stays in the follicle until a new hair grows to replace it. The old hair is then shed and the cycle repeats itself.
Anything that damages, infects or inflames the hair follicle can affect new hairs growing. If your dog is itchy they may damage the skin or break/pull out hairs with all the scratching and chewing.
Here are some of the more common causes of hair loss:
Parasites such as fleas and the demodex mite
Skin allergies
Skin infections
Ringworm (a fungal skin infection)
Hormonal conditions such as hypothyroidism (an underactive thyroid) or Cushing’s disease (excessive cortisol)
Seasonal flank alopecia - some dogs experience hair loss on the sides of their chest or abdomen at a certain time of the year (usually when day length is shortest), this sometimes regrows at other times of year and can happen in cycles. It is not uncomfortable or itchy.
Poor diet and nutrition
Contact alopecia when something rubs and shortens or removes fur for example around collars or on elbows.
Wounds and scars - hair loss can sometimes be permanent around deep wounds or scars.
Genetics - some breeds have been bred to have no hair such as the Chinese Crested or Mexican Hairless dogs. Others such as Dobermans, Daschunds, Greyhounds and Whippets sometimes suffer from ‘pattern baldness’ on the outer ear, chest, back, thigh or lower neck. This is only a cosmetic issue.
Diagnosing the reason for your dog’s hair loss
Your vet will look at where your dog’s hair is thin or bald, their age and breed and how long the problem has been going on for. It is also important to note whether they are itchy, as well as having a good look at any changes to the skin such as scabs, dandruff, spots. These may give more clues as to the cause.
Your vet is likely to advise some tests. Depending on your dog’s individual signs these may include:
Using a swab or by using some clear tape a small sample for the skin surface may be taken and put into a microscope slide and examined to look at the cells that are there and any bacteria or yeasts (cytology).
A deeper sample may be taken called a ‘skin scrape’ which involves using a scalpel blade to gently scrape hairless areas of skin. This is not as scary as it sounds and causes very little discomfort! This is to look for mites, mainly demodex mites that live in the hair follicles.
If ringworm is suspected some hairs may be plucked and put onto a special culture medium (a substance that is used to grow microorganisms ) or sent to a special lab instead.
Investigation into suspected skin allergies may be needed if your dog is itchy (see food allergy/atopy articles)
Blood testing and other more specific diagnostic tests may be undertaken if an illness like an underactive thyroid is suspected.
It is important to contact your vet if you suspect your dog may be losing their fur. Treatment depends on what is identified as the underlying cause. The good news is the majority of dogs with alopecia can be treated and their hair follicles will recover allowing a healthy coat to re-grow.
The vets at MyDogDoc are happy to answer any questions you have about your dog’s fur - see you in a consult soon!
