The pyotraumatic dermatitis, commonly known as Hot Spot, is a condition that frequently affects dogs from breeds with long thick fur, especially in the summer when the climate is hot and humid. It is a superficial bacterial infection of the skin which appears in an acute manner and which develops rapidly following a self-inflicted trauma.
The initial lesion appears because the animal licks, bites, scratches or rubs a region of his body that is itchy or causes him pain. Then, the bacteria present in this area start to multiply because the skin is no longer healthy and it no longer acts as a barrier against bacterial invasion.
Typically, we will observe a single, well defined lesion that is red, oozing, very itchy and that spreads rapidly. There may also be several at the same time. We find them on the torso, at the base of the tail, on the sides of the legs, on the neck as well as on the face.
A flea infestation constitutes the main reason why an animal self-injures. Among the other reasons, we find other parasites such as lice and mites, allergic reactions, anal gland problems, ear infections, infections of the hair follicles caused by bacteria, parasites and fungus, traumatic wounds as well as contact dermatitis.
The diagnosis is obtained after having eliminated the other diseases that can cause the same symptoms. With a cytology (microscopic observation of cells taken from the wound), we generally observe a mix of inflammatory cells and bacteria.
Firstly, the treatment consists in identifying and correcting the primary cause. Furthermore, a program of flea eradication is required, even if no fleas have been observed. Then, the wound must be shaved and cleaned, under sedation if necessary and an astringent solution applied locally for several days. Depending upon the severity of the itchiness, we can either use a cortisone based ointment applied directly to the lesion or a formulation given orally. Antibiotics may prove to be necessary during a period of 3 to 4 weeks. As for the prognosis, it is generally good if we arrive at controlling or correcting the underlying cause.