Causes of Hair Loss in Shih Tzus

Fleas are perhaps the first suspects to come to mind when you think of dog parasites, but ticks, lice, ear mites and mange are other major offenders. The presence and bites of these parasites will irritate your Shih Tzu and cause him to scratch, lick or chew himself to varying degrees of hair loss.

Staphylococci, or staph, are a bacteria normally found on the skin of your Shih Tzu (as well as your own skin). This bacteria usually causes no problems, but under certain conditions a staph infection can develop. Even in the early stages there may be some hair loss from your little dog's frequent scratching, chewing, licking or rubbing at the irritated areas. In the later stages of a staph skin infection, there can be rapid hair loss in the affected regions, along with extremely red, scaly, sore skin and severe itching. Many times, a staph skin infection is secondary to another condition, so it's essential that your vet determines and treats the underlying cause.

Two of the more common culprits of fungal hair loss are Microsporum and Trichophyton, more frequently called ringworm. Hair loss associated with this infection will typically appear in circular patches and the centers may have a dry, crusty appearance. Malassezia pachydermatis, a type of yeast, is another likely offender, and some veterinarians believe Shih Tzus are genetically susceptible to this infection. The condition will often cause mild to intense itching, and hair loss can occur in the affected areas. Like the staph infection, a yeast fungus infection is often secondary to another condition, which must be determined and treated.

Allergies are quite frequent in dogs, and the most common dog allergen is flea saliva. Even a single fleabite on a sensitive Tzu can make him severely itchy and utterly miserable. Atopy, however, is another likely possibility, particularly since the Shih Tzu breed tends to be prone to developing the condition, according to "The Merck Veterinary Manual." Atopy, or canine atopic dermatitis, can occur if your little dog has developed a sensitivity to an allergen in his environment, such as mold or pollen. Because one of the main symptoms of an allergy to an environmental irritant and to flea saliva is itching, the frequent scratching, licking and chewing your Tzu will resort to in an attempt to ease his discomfort can lead to skin lesions and hair loss.

If a gland in your Shih Tzu's body is producing an excessive or deficient amount of a hormone, you'll almost certainly see changes in the Tzu's skin and coat. Unlike the other conditions mentioned, hormonal problems are usually not itchy, but hair loss is common. Your little dog's skin may become thinner or thicker than normal, and you may also notice changes in his skin and coat color. Hormonal issues are extremely serious. Severe illness or even death can occur, so it's vital that these problems be diagnosed and treated appropriately.