Canine Pyoderma
(Bacterial Folliculitis)

Bacterial folliculitis is the most common type of bacterial skin infection in the dog. The Staphylococcus intermedius bacteria, which is a normal resident bacteria of canine skin, can cause infection of the skin in some dogs. Current theories indicate that most dogs who develop the infection, particularly recurrent infections, have an underlying abnormality of their metabolic or immune systems. This form of pyoderma is a frequent complication of allergies, skin parasites (mites, fleas) and endocrine diseases, like hypothyroidism.  An idiopathic primary bacterial folliculitis is also seen in short-haired dogs.

Located within the hair follicle, this bacterial infection causes:

• Inflammation in and around the hair follicle
• Itching in some cases
• Hair loss in many cases

The clinical signs of bacterial folliculitis can be quite variable and may include:

• Pustules
• Papules (pink or red swelling on skin), heat and crusts
• Erythema (redness)
• Alopecia (hair loss)
• Hyperpigmentation (darkening of the skin)
• Some dogs develop large circular area of hair loss with crusting or scaling around the border
• Superficial erosion
• Draining tracts
• Pain or discomfort
• Surface pyodermas
• Skin fold pyodermas (face wrinkles, vulva fold)
• Hot spot (pyotraumatic pyoderma)
• Superficial pyodermas
• Bacterial folliculitis in short-haired breeds
• Impetigo and bacterial folliculitis (pustular, immune disorders, Demodex mange)
• Mucocutaneous pyoderma (autoimmune disorders, metabolic disorders)
• Deep pyodermas
• This is a serious bacterial infection with inflammation of surrounding deep tissues.
• Furunculosis - rupture of infected hair follicles caused by deep fungal infections, eosinophilic autoimmune disorder with lesion on top of nose.
• Abscesses
• Chin acne
• Bacterial pododermatitis (fungal, autoimmune, foreign body, demodex mites, idiopathic)
• Lick granulomas and callus pyoderma

Diagnostic Tests:

• Skin scrapings for mites
• Fungal culture
• Wood's lamp examination for ringworm
• Bacterial culture

Treatment:

A satisfactory resolution of pyoderma comprises both the cure of the cutaneous signs and the prevention of recurrences.  As most pyodermas are secondary infections, the diagnosis and control of the underlying problem is mandatory for a good therapeutic success. If the underlying illness is not controlled, the pyoderma may recur after the antibiotics are interrupted. On the other hand, if the underlying cause is corrected, but the pyoderma is not treated, the bacterial infection may not heal on its own.

• While surface pyoderma may be treated with topical therapy alone, superficial and deep pyoderma require treatment with systemic antibiotics.
• Typically, a minimum of three weeks of antibiotic therapy is required.
• Requires a course of oral antibiotics for seven days past resolution of the clinical signs.
• An antibiotic that is effective at killing Staphylococcus intermedius and penetrates skin is indicated.

Shampoos:

Shampooing is the most frequently used treatment and it should be allowed to soak for 10-15 minutes, and then thoroughly rinsed. Treatments should be repeated initially 2-3 weekly, then tapered to twice monthly when the disease improves. An excessively frequent use, particularly of strong agents, such as benzoyl peroxide, may lead to excessive coat dryness and skin irritation.

Staphylococcal Bacterin:

Staphage Lysate is able to stimulate immunity and is effective in about 40% of the dogs with with staphylococcal hypersensitivity. The bacterin is given is subcutaneously initially twice weekly and then at a maintenance level of every 7-14 days.