Pyoderma is caused by a bacterial infection of the skin. Signs of pyoderma include red, irritated areas of skin, spots and pimples, scabs, wheals and purulent discharges from the skin. The severity of signs is often indicative of the depth of infection of the skin. Pyoderma is often seen secondary to other skin disorders rather than as a primary skin disease. Thus if your pet suffers from pyoderma it is important to try to ascertain if there is an underlying cause which should be treated.
Pyoderma is a condition which is seen frequently in small animal practice. It tends to be a problem of dogs much more often than cats. It is usually caused by bacteria which are found normally on healthy skin (commensal bacteria); these organisms are often opportunistic and they may proliferate and cause problems if the skin becomes diseased or damaged due to some other factor. The bacterial organism most often implicated in pyoderma of dogs is Staphylococcus intermedius.
Pyoderma may appear as itchy, red, inflamed areas of skin. Often there are spots and pimples which may then form scabs. There is often a distinctive unpleasant smell to the skin of affected animals. Some areas of the skin are particularly prone to developing lesions due to pyoderma. The folds of the lips, the ear canal, between the toes, the back and the groin are often affected by pyoderma. These areas tend to be ones where the skin creases or folds; this causes a lack of air circulation around the skin and hence these regions become warm and moist- ideal conditions for bacterial proliferation. Pyoderma may become a chronic problem for some pets.
Pyoderma often occurs as a secondary problem when skin is already damaged by another cause. Conditions such as infestation with skin parasites (especially fleas), atopy, dietary sensitivity, seborrhoea, and poor or excessive grooming may all lead on to pyoderma. Sometimes pyoderma may develop spontaneously (idiopathic or primary pyoderma) and in this situation there may be an underlying problem with the immune system; possibly an inherited factor is involved.
There are several different forms of pyoderma and these are most often classified according to the depth of the skin involved in the lesions. If bacteria colonise the surface of the skin and cause lesions this is known as surface pyoderma. This often shows as areas of red, inflamed and irritated skin; raised scabs may form on the skin and the dog may lick or scratch the area intensely. This is often called a "hot spot" if it is localised to one particular area.
If the bacteria have reached the level of the hair follicles which remain intact then this is known as superficial pyoderma. Lesions in this type of pyoderma may show as pus filled spots which go on to form wheals and scabs.
Deep pyoderma is the most serious type and can make the dog become systemically ill. In the deep form of pyoderma the bacteria have infected the skin beyond and beneath the level of the hair follicles. This form may show up as skin abscesses and infected, inflamed channels which may ooze pus on the skin surface.
If your dog shows any of these signs it is sensible to take him along to your vet. It can sometimes be quite difficult to tell the difference between pyoderma and yeast infections caused by organisms such as Malassezia so be prepared for your pet to undergo some tests if the vet is unsure of the correct diagnosis at first.
Once a diagnosis of pyoderma has been made your vet may be able to help you determine any underlying causes of the problem and will also be able to perform various tests to ensure the best possible treatment for your dog. Sometimes it may be necessary to take skin scrapings, swabs, hair plucks, blood tests or even skin biopsies to try to ascertain an underlying cause for the problem; this is known as a dermatological work up and although it can be expensive it is occasionally necessary to establish a reliable diagnosis and treat the condition effectively.
Treatment of dogs with pyoderma will depend upon the severity of the problem and any underlying cause. Dogs should start treatment as soon as the first signs of pyoderma are noticed. Try to identify and eliminate any underlying causes. It is always a good idea to blame fleas initially, (they should be assumed guilty until proven innocent!). Even if you have seen no fleas on your pet always assume that they are the cause of skin problems and treat your dog regularly for fleas whether you see them or not. Consider the possibility of a dietary sensitivity if flea eradication does not seem to reduce the signs of pyoderma; you may wish to try your pet on a hypoallergenic diet. Essential fatty acids may help to maintain the condition of the skin. Veterinary formulations containing essential fatty acids are readily available; I would recommend one called Viacutan. Keep the skin clean (consider bathing your dog every three days or so with a good quality shampoo such as Etiderm for surface pyoderma or Paxcutol for superficial or deep pyoderma) and ensure that areas where the skin folds and creases are cleaned and dried every day (I often suggest well diluted Hibiscrub for this purpose). You could try to maintain the condition of the skin by using a moisturizing product such as Humilac. A product called Dermacool may be used to ease the discomfort of skin inflammation and hot spots. Once the skin condition has eased consider shampooing regularly to try to prevent the condition from recurring or to reduce the frequency of recurrence.
If these simple measures are insufficient to treat your dog's skin condition then antibiotics will probably be required. In cases of surface pyoderma such as hot spots, an ointment such as Fuciderm may be all that is required to treat your pet effectively. However where the infection extends deeper into the skin then systemic antibiotic medication may be needed. Occasionally antihistamines may be prescribed to reduce the discomfort and self trauma to the skin caused by the itching and scratching activities of your pet. Corticosteroids are most likely to be avoided in the treatment of pyoderma. Medication may be required for quite some time; 6 to 8 weeks or more on antibiotics may be necessary to treat the problem and treatment should usually be continued for a while after the skin seems to be cured to try to prevent recurrence of the condition once the antibiotics are withdrawn.
If your dog suffers from pyoderma it may be a chronic problem and you will soon become used to the signs of a flare up beginning. If this is the case you may be able to take many measures at home to help your pet. Only attempt home treatment if your dog is not showing severe signs of discomfort and does not have suppurating or raw areas of skin. Probably one of the most helpful measures is to keep the dog's skin clean and dry by regularly bathing your dog and wiping under any skin folds with a good quality shampoo followed by thoroughly rinsing drying your pet. This together with controlling skin parasites and any necessary dietary measures such as an hypoallergenic diet or dietary supplements could really help to ease the problems of pyoderma.