Also known as "alopecia" hair loss isn't a disease in itself but a symptom of an underlying condition. All cats lose hair (shedding), but alopecia is defined as an excessive loss of hair.
What causes alopecia?
There are many possible causes of alopecia in cats, and they can be defined as pruritic/self-induced or non-pruritic/non self-induced. Below are some possible causes:
- Flea allergy dermatitis - Allergy to the saliva from the flea bite.
- Food allergy - Allergy to a protein in food. Fish, beef, and chicken are the most common causes of food allergy.
- Inhalant allergy - Allergy to an inhalant such as cigarette smoke.
- Notoedric mange - Mange caused by spider-like parasites.
- Ear mites - Tiny spider-like parasites which live in and around the ears causing intense itching.
- Psychogenic - Compulsive over grooming.
- Pyoderma - Bacterial infection of the skin.
- Abscess - Walled off collection of pus located in the tissue. Usually, the cause is a cat bite.
- Hyperthyroidism - Usually caused by a benign tumour of the thyroid gland.
- Stress - Surgery, new pet, new baby, illness etc.
- Cushing's syndrome (hyperadrenocorticism) - Excessive levels of cortisol in the blood either caused by the adrenal glands or the administration of steroids.
- Ringworm - Fungal infection.
- Feline Acquired Symmetrical Alopecia - The exact cause isn't known, it is believed to be a hormonal disorder.
- Drug reaction (topical, injected).
- Telogen defluxion - Hair loss which occurs during the resting phase of the hair growth cycle).
- Anagen defluxion -Hair loss which occurs during the growing phase.
- Seborrhea - Excess secretion of sebum.
- Stud tail - Hypersecretion of the glands located at the base of the tail. As the name would suggest, this condition is seen most often in entire males.
How is the cause of hair loss diagnosed?
Your veterinarian will perform a complete physical examination and pay careful attention to the location, size, and shape of the hair loss if any other symptoms are also present and obtain a medical history from you. He will need to establish if the cat has been scratching, itching, how long it has had symptoms if it has recently had any medication (topical flea/worming products, injection etc).
Some diagnostic tests your veterinarian may wish to perform include;
Trichogram - This is a microscopic examination of the hair root. Broken tips indicate that the hair loss is self-induced.
- Fungus culture - To look for ringworm.
- Food elimination trial - Your veterinarian will place your cat on a food trial which usually lasts between 8-12 weeks. During this time, you must not give your cat any other foods, vitamins, minerals or chewable medications apart from the prescribed diet. If any other foods or vitamins are given during this trial it will invalidate the results. If the allergy clears up after the specified time then a food allergy is the likely cause. The diet given to your cat during the trial will be a food the cat has never had before such as rabbit, duck or venison. The diet may be home made or a special 'prescription' diet. After the trial, if the cat's allergies have cleared up it will be placed back onto his regular food and if after a short period of time the allergies return then it is safe to conclude that the food was the cause of the allergy.
- Specific blood tests to check for hyperthyroidism.
- Specific blood tests to check for Cushing's syndrome.
- Skin scrapings - These are studied under a microscope to look for mites.
Treatment of alopecia in cats:
Treatment depends on the underlying cause of the alopecia and may include.
Ringworm - Lime sulfur dips, anti-fungal drugs.
Food allergies - Switching to a novel or low allergenic diet.
Hyperthyroidism - Radioactive iodine to destroy the tumour or surgery to remove it followed by lifelong replacement of thyroid hormones.
Cushing's syndrome - Gradual withdrawal of corticosteroids if veterinary induced, surgical removal of the affected adrenal gland if a tumour is involved, surgical removal of both adrenal glands if a pituitary tumour is the cause.
Inhalant allergy - Avoidance of the allergen if possible.
Notoedric mange - Clipping, weekly lime sulfur dips, Revolution.
Ear mites - Removal of the exudates, an insecticide such as Revolution.
Psychogenic - Behaviour modification, keeping your cat in a stress-free environment and drug therapy (if other methods fail).
Pyoderma - Antibiotics and clipping the affected area.
Abscess - Draining of the abscess and antibiotics.
Feline acquired symmetrical alopecia - Hormones, although not all veterinarians recommend this.
Drug reaction - Switching or discontinuing medications.
Seborrhea - Shampoos, omega-3 fatty acids, antibiotics.
Stud tail - Antiseborrheic shampoos, neutering (where possible).
Sunburn - Severe sunburn may be treated with topical or oral steroids.