There are a number of skin abnormalities that affect most dogs. These skin conditions can be congenital or hereditary, though most of them are quite rare. However, there are some skin abnormalities that have a higher rate of occurrence in certain breeds of dogs, and these are discussed below.
Congenital Skin Diseases
One particular skin disorder that could be typically described as absent skin is epitheliogenesis imperfecta, which is also known as aplasia cutis. This happens to be a congenital condition whose origin is not known and commonly affects livestock, such as sheep, cattle, horses, and pigs. It is only in extremely rare cases that it affects cats and dogs. Epitheliogenesis imperfecta tends to cause a failure of the animal to grow portions or all of the skin layers. The consequence of this is that the animal is born with certain sections of its skin lacking covering, or with ulcers. If such a condition involves a big portion of the skin, then it can be fatal to the affected animal. However, small patches can be corrected by surgical means.
A birthmark, or nevus, is simply an inborn pigmented part of the skin of a human. However, when it comes to animals, the term nevus refers to any malformed section of the skin, as well as unusually pigmented spots. There are particular types of nevi that displace the usual skin structures, such as hair follicles, causing hairless patches. If the nevi don’t cover a particularly wide area, they can be eliminated by surgical means, treated through freezing (cryotherapy), or via laser treatment. Otherwise there is no existing treatment that is effective.
Dermoid cysts are inborn defects which seldom occur in dogs, with the exception of Rhodesian Ridgebacks, in which they are hereditary. They are pockets of skin in which oil, hair, dander, and other fragments collect. They usually appear on the skin on top of the spine, though they are seldom linked to spinal cord neural deficits. It is possible to remove them via surgery.
Hereditary Loss of Hair (Alopecia)
It is a fact that when dogs are born, they can either be totally or partially hairless, though this lack of hair can also develop later in life. Alopecia can be linked to other developmental disorders such as abnormal eyes, claws, teeth or skeleton. Dogs such as the American Hairless Terrier, Chinese Crested, and Mexican Hairless have all been bred for such defects. There tends to be numerous infrequent cases that affect other dog breeds, particularly the male of the species. The affected animals, including the hairless breeds, develop hairless patches together with related dental anomalies. Every animal that has irregular follicular development is susceptible to infections of the hair follicle, and inflammation of hair due to a foreign body.
Dogs are vulnerable to a number of hair follicle abnormalities. Colour dilution alopecia is a syndrome linked to the gene that turns hair from the usual black to a blue, fawn, or beige colour. It is common to Doberman Pinschers, although colour-dilute Dachshunds, Yorkshire Terriers, Italian Greyhounds, Whippets, Greyhounds, and tricolour hounds are also affected. Dogs affected by this disorder usually have normal hair coats at birth, but start to develop inflammation of hair follicles and gradual loss of hair in the blue or fawn-coloured areas, before they turn 1 year old.
Black hair follicle dysplasia develops faster, causing greater hair loss especially in dogs that are either white or black. It effects are seen soon after an animal is born, and only affects areas that are black in colour. Papillons and Bearded Collies are the most susceptible to this disease though seasonal flank alopecia can develop in and Airedale Terriers and Boxers. Spitz-type breeds can also develop different kinds of post-clipping alopecia and woolly syndromes.