Alopecia in cats

There is a fine line between normal grooming behaviour in cats and over-grooming. A cat that is over-grooming has hair loss over the back, sides of the back legs, inside of the thighs and tail base area. In severe cases, there is damage to the skin, with sores and sometimes infected wounds. An out-of-context or irrelevant response to anxiety is called a displacement behaviour. During a social conflict, for example, a harassed cat may be undecided about whether to run from its attacker or to stand and fight. Instead, the cat displays a third, unrelated behaviour, such as grooming. This is a normal activity that cats find calming and reassuring. If the displacement behaviour becomes a habit and is generalized to any stressful situation, it becomes a stereotypy--a prolonged or repetitive behaviour that serves no apparent useful purpose and, in some cases, is actually self-destructive. Stereotypies are sometimes compared to obsessive-compulsive disorders in humans.

Causes  

Diseases that can directly cause destruction or damage to the hair shaft or follicle include bacterial skin diseases, dermatophytosis, demodicosis, severe inflammatory diseases of the dermis (eg, juvenile cellulitis, deep pyoderma), traumatic episodes (eg, burns, radiation), and (rarely) poisonings caused by mercury, thallium, and iodine. These diseases tend to be inflammatory.

Diseases that can directly inhibit or slow hair follicle growth include nutritional deficiencies (particularly protein deficiencies), hypothyroidism, hyperadrenocorticism, and excessive oestrogen production or administration (hyperestrogenism, Sertoli cell tumors, oestrogen injections for mismating). Temporary alopecia in horses, sheep, and dogs can occur during pregnancy, lactation, or several weeks after a severe illness or fever. These types of alopecia tend to be noninflammatory unless a secondary infection of the skin develops.

Pruritus or pain is a common cause of acquired inflammatory alopecia in animals. Diseases that commonly cause pruritus or pain include infectious skin diseases (eg, bacterial pyoderma and dermatophytosis), ectoparasites, allergic skin diseases (eg, atopy, food allergy, contact, insect hypersensitivity), and less commonly neoplastic skin diseases. Friction may cause local hair loss, eg, poorly fitted halters or collars. Rarely, excessive grooming may be the cause of hair loss in some animals, particularly cats.

Feline endocrine alopecia is no longer recognized as a bona fide syndrome; the new name is feline acquired symmetric alopecia. To date, there is no documented evidence of an endocrine disease in these cats, and the symmetric alopecia seen is a clinical sign of an underlying disease, most commonly a pruritic disease.

Psychogenic alopecia due to stress is probably a number one cause of this problem. That's not to say your cat is highly-strung. Often cats who over-groom are normally quite sedate. In a lot of cases, a contributing factor is a past or recent trigger, such as moving house, a stray cat hanging around outside the house, moving house, introducing a baby into the household. These little things can be highly stressful to some cats, and although they may not show signs of being stressed (such as aggression, aloofness or hiding), they can express their anger at a situation inward and take it out on themselves by licking constantly. This disease can be compared to obsessive compulsive disorder in humans, where people constantly wash their hands, stay up at night to clean the house, etc. It is usually a result of not being able to deal with a stress. Other causes of alopecia include:

Treatment

In psychogenic alopecia, working out the cause of the anxiety can be difficult, but often it is fairly obvious. Fortunately cats are not as complex as humans when it comes to psychological problems. The triggers which cause this disease in cats are usually only one or two things. Cats do not stay up all night worrying about mortgage repayments or working out how to juggle two jobs with caring for a family. They don't suffer guilt like we do and rarely feel remorse for things that have happened.

Increasing environmental stimulation (play centres, chew toys, food or catnip packed toys, kitty videos, increased interactive play) can all be tried, particularly if the behaviour tends to occur in the owner’s absence. Toys should be kept out of the cat’s reach until put out daily by the owner. Then the toys should be rotated every 1 - 3 days to provide different play items. When home the owner should provide periods of interactive play and perhaps even a short training session to keep the cat occupied and focused. Attention should never be given to the cat when the behaviour is exhibited. In fact, inattention or some form of remote punishment device, may be the best way to ensure that no rewards are given. Remote devices such as a water rifle, a can of compressed air, or an ultrasonic or audible alarm may also serve to interrupt or deter the undesirable behaviour without causing fear of the owner. As soon as the undesirable behaviour ceases, the owner should immediately engage the cat in some alternative acceptable behaviour (e.g. play, chew toys). The owner should also try to identify environmental or social changes that may be contributing to anxiety and the behaviour.

In cats, as with humans, medication is usually required to help reduce the anxiety that the sufferer feels. Although not labelled for treatment of psychogenic dermatoses in animals, behaviour modification drugs may be useful for treatment of feline psychogenic alopecia, characterized by excessive self-licking. The most commonly used drugs are Phenobarbital (0.5-2.2 mg/kg, b.i.d., or 15 mg/cat, twice weekly) and diazepam (1-2 mg/kg, b.i.d.). Sedation is the most common side effect. Diazepam is also an appetite stimulant in cats. Idiosyncratic fatal hepatic necrosis has been reported in several cats treated for behaviour problems for 8-14 days.
       
Tricyclic antidepressants, such as amitriptyline (Clomicalm - 1 mg/kg, b.i.d.), are potent H1 blockers in addition to inhibiting uptake of serotonin and norepinephrine. These drugs can induce cardiac arrhythmias and lower the seizure threshold. Other side effects include dry mouth, hypersalivation, vomiting, constipation, urinary retention, ataxia, disorientation, depression, and anorexia. Tricyclic antidepressants should not be used concurrently with monoamine oxidase inhibitors, including amitraz dips for demodicosis. Dosages should be tapered slowly when discontinued. Prozac (Fluoxetine -1 mg/kg, s.i.d.), a selective serotonin-reuptake inhibitor, may be effective in treating pruritus or chronic licking in some dogs and cats. A single dose of the endorphin blocker naloxone (1 mg/kg, SC) may be effective in cats with psychogenic alopecia. A change in grooming habits lasts for a variable period of time (1 wk to 6 mo). Naltrexone (2.2 mg/kg, s.i.d.) has been used in dogs with some success.

Most vets recommend using either an anti-inflammatory drug such as cortisone tablets given daily or as a single depot injection (such as Depomedrol), which will help relieve the itchiness that comes from the cat's skin being damaged all the time, to treating with anti-anxiety medications. The most common anti-anxiety drugs used in cats are Clomicalm® and Prozac®