Skin disease can usually be placed under 3 subheadings; infectious,
allergic, toxic. Infectious and allergic dermatitis (literally
inflamed skin) are the more common skin problems, but chemical
exposure or contact can result in reaction.
Allergic Dermatitis
One of the most common problems seen with dogs is an allergy.
Allergies occur when the immune system ‘over-reacts’ to foreign
substances (allergens) the body is exposed to. The common reaction
is itchiness, either localised to one area or generalised across the
body. The reaction to this itchiness is to chew, lick or scratch.
This can lead to hair loss, open sores and scabs and can lead to a
secondary bacterial infection.
Treatment for allergic conditions involves removing the source of
the allergy. Unfortunately, this is sometimes impossible, depending
on what the allergic response is aimed at. Some dogs can be
desensitised to allergens, where a tiny dose of the allergen is
injected into the dog over a long period of time.
Symptomatic treatment is often the first line of treatment, where
the over-active immune response is reduced to near normal levels.
This provides relief from itchiness, but does not cure the allergy.
Some allergies are seasonal, and need only to be controlled during
the worst part of the year (usually summer).
There are several different ways to control the symptoms of allergy,
these depend on the animal and the severity of the signs.
Bacterial Dermatitis
Dermatitis can often be as a result of bacterial infection, most
commonly due to Staphylococcal bacteria. Staph bacteria are normally
present on the skin of animals and humans, but they are considered
opportunistic invaders. When the skin is healthy, there is often no
problem, but when the surface of the skin is irritated or broken,
they can invade and rapidly multiply until they cause disease.
Problems that can cause itchiness often result in secondary
infections, usually with Staph bacteria.
Staphylococcal infections usually appear as red areas of inflamed
skin with either a pimple-like pustule in the middle or a larger,
circular area or moist inflamed skin with a crusty edge and hair
lost in the middle.
Skin biopsy and bacterial cultures can confirm a Staph dermatitis.
Staph infectious dermatitis is not infectious, as Staphylococci are
normally found on living skin of all people, dogs and cats.
Treatment of Staph dermatitis revolves around reducing the number of
bacteria present and eliminating any other problems that may have
lead to scratching, such as allergies or fleas. Bacterial culture
and sensitivity can determine a suitable antibiotic to use. Regular
use of antibacterial shampoos can keep bacterial populations under
control also removing loose hairs and dead skin flakes. Some
infections require between 3 and 6 weeks of antibiotics therapy
before coming under control.
