Certain causes of hair loss in animals have a general cause and can affect both cats and dogs. Other aspects of hair loss are specific to dogs. Before a diagnosis can be made it must be established whether the hair of the dog is falling out. The alternative is the dog is scratching and causing the hair to fall out. This means that there is an underlying cause of the itching. It may be caused by an allergy, a parasite or a skin infection.
Hair loss may also occur because the hair follicles have stopped cycling, which means no new hair growth starts. Usually this is seen on the trunk and the hind legs, and it is not accompanied by any marks or inflammations.
Many diseases and conditions are associated with hair cycle abnormalities. These include endocrinal diseases such as hypothyroidism and Cushing’s syndrome, alopecia X, cyclic flank alopecia, pattern baldness, post-clipping alopecia, and telogenic defluxion.
- Flea associated dermatitis
This affects both cats and dogs. The bite of a single flea can cause this condition, and sometimes it may be difficult to find, particularly in dark haired pets. Fleas often seem to prefer the area of skin that is just in front of the base of the tail. If the coat of dogs has a brittle or broken crop of hairs in this area it is usually fleas. Another telltale sign is that the hair has a distinctive smell it is musty.
Treatment
A topical flea control medicine is usually an effective treatment.
- Canine Atopy
When humans have a typical allergic reaction, the respiratory system is often involved. In dogs the skin is involved. Unfortunately anti histamine treatment is not effective for dogs. The diseases are usually inbred and this means that dogs have a genetic predisposition to allergic reactions.
Treatment
Shampoos, or a soothing cream. Bathing agents that reduce the presence of yeast and bacteria are often helpful.
- Pyotraumatic Dermatitis (Hot Spots)
These hot spots are more likely to occur in dogs with rich oily coats. Golden Retrievers, Cocker Spaniels, Spitz, Samoyed, Chows, Akitas, and the Pyrenean mountain dogs are examples of breeds that suffer. Intense itching occurs in one or two isolated area of the trunk of the body. This itching inflames the local area, and the skin is often raw within a few hours. It is helpful to restrain your pet as the dogs bite, scratch and aggravate the area and make the condition worse. This condition can re-occur or it may be a one off. Treatment depends on the severity of the case and can include a topical ointment, an astringent, a cortisone cream, or an anti-inflammatory injection. It is rare to need antibiotics.
- Mange hair loss
There are two distinct types of mange
Demodectic mange
Demodectic mange, is a genetic disorder often found in young dogs. A parasite, which lives in the hair and oil glands of the skin of all dogs, begins to multiply exponentially. It runs in certain lines of dogs and is more common in certain breeds of dogs
It causes no itching but the involved areas are subject to secondary bacterial infection.
Treatment
It is treated with Mitaban (amitraz) dips or with ivermectin.
Sarcoptic mange
Sarcoptic mange is due to a transmissible parasite that burrows through the layers of the skin causing intense itching. It passes from pet to pet through contact. It will attack humans as well.
Treatment
It is easily cured with ivermectin given orally or by injection.
- Ringworm
Despite the name of ringworm it is not a parasitic worm it is a fungal infection. It does not itch and as its name suggests it is round. It is transmitted by contact. The hair in the area breaks off when the fungus attacks the hair shafts. It may spontaneously disappear especially in cats yet the animal remains a carrier of the fungus.
Treatment
It is treated with fluconozole, itraconazole, griziofulvin and topical iodine preparations.
- Nervous or Stress/Boredom Induced dermatitis
This is quite common in most of the terrier breeds. It is more common in dogs than cats and more common when the dog is left alone. It also occurs due to persistent licking of an area in older, obese or lame pets.
It is hard to cure.
Treatments
Some treatments include topical bitters mists, relieving boredom, anti obsessive/compulsive behavior drugs such as chlomipramine, and taping isolated areas with a protective covering.
- Food Allergies hair loss dermatitis
Dogs with this problem have a permanent itch. Dogs have cells which release anti histamines, when the dog eats certain proteins. This condition is difficult to isolate so all the other treatment options for the above causes of hair loss in dogs should be assessed first.
Treatemnt
The treatment is placing the dog on a trial diet for two or three months
- Hair loss under collar
When a dog’s hair keeps getting caught in the collar they will lose it. A change of collar is all that is needed. However hair rubbing under a collar can be an early warning sign of disease in some dogs.
- Cushing’s syndrome.
Cushing’s syndrome is also a human condition. In dogs it can be mistaken for general ageing as it results in weight gain, hair loss, and urinary incontinence.
Treatment
The treatment depends on the age and condition of the dog.
