Pyoderma in the Canine

Pyoderma

Bacterial skin disease

Pyodermas are common in small animal practice, particularly in the dog.

There are several ways of classifying pyoderma but the easiest way to understand this disease is to think about the thickness of the skin and to define the infection on how deep the bacteria infect the skin cell layers

Surface pyoderma: This is where bacteria colonise the outermost layer of the skin.

Superficial pyoderma: The bacterial infection is at the level of the intact hair follicle.

Deep pyoderma: The bacterial infection extends beneath and beyond the hair follicle.

Causative bacteria

The vast majority of cases involve a natural resident of the skin called Staphylococcus Intermedius which becomes pathogenic (disease causing) when the skin environment changes for a number of different reasons. Other bacteria and other micro-organisms may be involved but some reports suggest that over 90% of cases have Staphylococcal involvement.

What does pyoderma look like?

The most common, owner response is that the dog itches, has red areas, often with pimples or scabs and the pet may smell. Surface pyodermas may show as areas of redness and irritation, often developing in raised round, scabs. Superficial pyodermas produce yellow spots which then break out into larger wheals and scabs. Deep pyoderma can make pets systemically ill and produce abscesses and oozing, inflamed channels in the skin surface. Certain areas may be particularly prone to infection. Interdigital areas, inside ears, the groin and along the middle of the back are common sites in the dog. Other diseases such as yeast infections can look very similar and so if there isn't a rapid resolution with home treatment, seek professional advice.

Why does pyoderma occur?

There are too many reasons to list here but a few of the common reasons are suggested below.

Primary pyoderma

There is little doubt that occasionally pyoderma may develop spontaneously and for no obvious clinical reason (idiopathic). The general consensus is that these dogs probably have a compromised immune system or a congenital / inherited factor affecting skin immune systems.

Atopy

A name given to contact and inhaled, chronic hypersensitivity disorders, often with an inherited base. Certain breeds are particularly susceptible. Speak to your veterinarian at length on this complex and difficult subject. Allergens incriminated vary from the house dust mite and plant pollens to human skin cells! The inflammatory skin changes, again, leave your pet open to secondary pyoderma.

Ectoparasites

Especially fleas. Apart from the trauma and irritation of individual flea bites, many dogs develop an allergy to flea saliva causing a generalized skin inflammation. This changing skin environment allows pyoderma to develop. See Flea Control and Parasitic Skin Disease In any case of pyoderma, assume fleas may have a role to play until proven otherwise.

Dietary allergy

Not as common as people would like to believe but is occasionally seen in dogs and because of the common daily inclusion of beef, chicken and wheat based products in dog foods we are seeing dietary intolerances being manifested as skin allergies with secondary pyoderma. Change to a hypoallergenic diet, such as Hills Canine d/d after consultation with your veterinarian.

Skin trauma

Working dogs, in particular will again receive occasional wounds when working in the 'rough'.

Poor grooming

And coat condition.

Seborrhoea

This is often an underlying cause for pyoderma. See Seborrhoea

Other lesions

Can cause this from furunculosis (often inherited) to 'hot-spots' due to excessive licking and scratching.

How to treat pyoderma

The foremost advice is that if your pet is rubbing itself raw and suppurating from a wound, go and see your veterinarian. However in nine out of ten cases this isn't the case. Because pyoderma tends to be a chronic disease many clients are used to recognising the symptoms and can manage the condition at home provided they use the correct medications. Follow the rules below:

Remember each type of pyoderma requires a different type and level of treatment.
Treat early, as soon as your dog shows symptoms.
Look for a primary cause.
Blame fleas every time unless proven otherwise.
Question why the skin condition may be allowing secondary pyoderma to occur.
Think about changing diet to a hypoallergenic diet.
Use an EFA such as Viacutan to improve skin nutrition and reduce inflammation.
Ensure that the skin is well moisturized and clean with a product such as Humilac
Cool 'hot spots' and areas of inflammation with Dermacool
Treat surface pyoderma with twice weekly shampoos with Etiderm
Superficial and deep pyodermas will require the shampoo Paxcutol
Prevent reoccurrence with healthy skin maintenance including regular shampooing with Sebocalm

The next stage

Your dog may have a more severe pyoderma. If this is the case, visit your veterinarian and seek his / her advice. Most bacteria will respond to a course of antibiotics but this can be protracted and expensive. Other drugs such as anti-histamines may be used in the first instance.

If your vet has doubts, he / she may ask to perform a 'dermatological work up' on your pet which will include swabs for bacteriology and yeasts, scrapings and pluckings for mange and ringworm, blood tests for allergies and generalized disease and skin biopsies.

In conclusion

Look for the primary cause as pyoderma is often secondary. Early treatment with good quality products and maximizing skin quality as a preventative measure is better and cheaper than treating 'flare-ups' of the disease.