Why is my cat losing his hair?

By Dr Megan Kelly

As with dogs, skin conditions can be extremely frustrating to solve and they often end with several visits to the vet to rule out all the different causes by doing diagnostic tests as well as seeing the response to treatment.

Excessive itchiness often results in excessive grooming which can then result in hair loss, scabs and skin inflammation. However, it is difficult to know whether excessive grooming is due to itchiness as sometimes cats may also groom when they are stressed. The licking stimulates endorphin release, which are feel good hormones and this helps to decrease the cat’s stress. So vets need to work out is the hair loss is caused by a skin lesion or if it’s a behavioural issue. And if it is a skin lesion what the cause is so it can be treated effectively. Your vet will do a series of diagnostic tests, take a thorough history and look at the distribution of the hair loss as certain areas may be indicative of specific causes. E.g. flea allergy dermatitis is usually on the back towards the tail.

So what causes excessive grooming?

1. Allergies

a) Fleas: One doesn’t always see fleas on your cat (often due to the continuous grooming). Look out for flea dirt which can be identified by small flecks of digested blood often found directly on the skin or stuck to the hair. If you see fleas on your cat this only represents 10% of the fleas present. There are usually another 90% in the environment e.g. in the carpets, under the skirting boards, couches etc.

b) Food: Hair loss and lesions are usually seen around the head and the face.

c)  Atopy: This is the term used for an allergy to something in the cat’s environment. For example pollens and dust mites. This skin condition is often seasonal and it is usually something we cannot pinpoint and is often diagnosed after all other causes have been excluded. Vets can do intra-dermal and blood allergy testing but it is questionable how accurate and sensitive these tests are.

2. Parasites e.g. mites, fleas, ticks. The damage to the skin can often  result in a secondary bacterial skin infection. Check other animals your pet has been in contact with to see if they also have symptoms.
3. Bacteria, fungus, and  yeast: This can be secondary and often  makes the itchiness worse.
4. Psychogenic: This can often be due to stress.
5. Systemic: Sometimes a skin condition may be a sign that there is  something more serious going on in the  body..

In order to treat a skin condition one needs to work out what the cause is exactly. Remember treating and diagnosing skin conditions is always a process and  often vets will rely on the pet’s reaction to specific treatments to assist in the diagnosis.

1. Flea control: This involves topical treatment as well as treating the environment. The ideal condition for fleas  are 21 – 26 degrees centigrade. Eggs are usually laid 1-2 days after a meal. For this reason using products that actually kill the fleas instead of just repelling them is usually more effective.
2. Skin scrapes, hair plucks, cultures etc to rule out parasitic  and infectious causes.
3. Food trial: This is always difficult  in cats that roam as they can get food from the neighbours and they may hunt. We usually try for 12 weeks, changing the protein and I always recommend completely excluding grains.
4. Symptomatic relief: In all skin cases no matter what the cause.

a) Shampoos:If your cat will allow this, medicated shampoos can be beneficial.

b) Natural products: e.g. herbal, homeopathic, tissue salts.

c) Fatty acid supplements

d)  Antihistamines: (to be prescribed by your vet) can relieve symptoms at times.

e) Cortisone: As a last resort and to be avoided if possible. (to be prescribed by your vet)

5. Immunotherapy: This can be effective in cases that have been diagnosed with atopy where a specific allergen has been isolated. Labs can make up hyposensitivity vaccines which given over time decrease the reaction that the cat has to the allergen.