When we look at a baby puppy, we see tiny, adorable creatures, wagging tails, and little pink bellies. What we cannot see is that the puppy’s body is developing in parallel with its own private ecosystem. Outside the body and within, a puppy’s microflora, also called microbiota, consists of a host of bacteria, mites, and other microscopic organisms that coexist with the growing dog. Under normal circumstances, as puppies mature, their immune systems develop the ability to manage and limit these microscopic populations.
It is not uncommon for there to be a hitch in this coeval development, and it only takes the smallest incident to upset the delicate balance between a puppy’s nascent immune system and her microflora. Should such a disturbance occur, these normally harmless organisms — one of which is the bacterium Staphylococcus intermedius — can become opportunistic attackers. Unchecked, this particular set of bacteria experience a population explosion and cause the skin infection called pyoderma in dogs, or puppy impetigo.
What is impetigo?
Canine pyoderma can affect dogs of any breed and of any age, though it is most frequently seen in puppies. This is good news, because as a puppy’s immune system continues to develop, the puppy’s body — its immune system, body hair, and natural skin oils — adjusts to the presence of its microflora. Once puppies reach physical maturity, most are able to keep their native bacterial populations in check.
“Puppy impetigo” is an approximate name, associated with a very similar bacterial skin condition commonly observed in human toddlers called impetigo, or colloquially infantigo, a term which underscores that this particular health issue primarily affects the very young. Whether in humans or puppies, the proper name for the problem is pyoderma, which means an irritation of the skin where pus is present.
Pyoderma in puppies can take a variety of forms, one more severe than the next. The most basic is superficial impetigo, where skin irritation and infection are on the surface of the skin. This self-limiting health issue is easily treated and tends to appear only during puppyhood.
What causes pyoderma in dogs?
This is a tricky question to answer, because puppy impetigo can flare up under a variety of situations. The Staphylococcus intermedius bacteria is the culprit, but it becomes an infectious agent and causes symptoms associated with pyoderma only under specific conditions. Puppy pyoderma usually affects the surface of a puppy’s body, in sites like the belly where the skin is exposed.
It is a secondary infection, which means that some disturbance has already occurred. Typical scenarios under which the bacteria go from being commensal, or living on the body without causing benefit or damage, to being infective agents include:
- Abrasions, wounds, and cuts
- Excessive moisture
- Skin allergies, whether to fleas, food, or other environmental factors
- Thyroid hormone deficiencies
- Genetic predisposition
The last factor, genetics, is the most predictable, since puppy impetigo is often seen in certain dog breeds. Puppy impetigo tends to afflict puppies with skin folds. From not being dried sufficiently after a bath to playing in puddles after rainstorms, dogs can easily find water trapped in wrinkly skin, commonly in breeds like Boxers, Bulldogs, Chinese Shar-Peis, Mastiffs, and Pugs. It is also seen in German Shepherd puppies with short coats.
Symptoms of impetigo in puppies
Impetigo’s proper name, pyoderma, gives us an indication of its major symptoms. A puppy with pyoderma will begin showing signs wherever there are areas of exposed skin, like the stomach. The most notable and obvious symptoms of canine pyoderma are epidermal collarettes. At first glance, a puppy with impetigo will appear to have a rash made up of small red circles, similar to ringworm.
Upon closer inspection, though, the irritated skin has a number of lesions, sores, or blisters closely resembling pimples in humans. These pus-filled collarettes may look alarming, but neither your family or other pets are at risk; impetigo in puppies is not a zoonotic nor a contagious disease. The symptoms and noncontagious nature of puppy impetigo link it to other canine manifestations of dermatitis, like ringworm or hot spots.
An accidental cut, scratch, or scrape is the perfect site for a dog skin infection to arise and spread. If a puppy suffers from allergies, excessive scratching can create the very breaks in the skin that lead to bacterial infection. Regardless of the cause, the longer the source of the infection goes untreated, the more the affected puppy scratches, licks, or bites at her skin. Aggressively tending to one wound will, in time, yield others nearby, leading what had been a localized infection to spread across the body.
As the infection progresses and pustules are disturbed, new ones will form and old ones scab over. Advanced pyoderma affects not only exposed skin, but can move into areas where the puppy’s coat is already established. In these cases, look for signs like alopecia, or limited hair loss, accompanied by skin discoloration around the trademark collarettes.
Treatment for pyoderma in dogs
Fortunately, superficial pyoderma in puppies tends to be self-limiting. As a puppy’s immune system develops its full capacity for protection and begins to assert itself, he becomes much more proficient at keeping his native microflora under control. All the same, when you notice a puppy’s tender belly is dotted with pimples, a visit to the veterinarian is your best course of action.
Once a diagnosis is confirmed, there are a range of treatment options available, including oral and topical antibiotics. The vast majority of puppies who suffer occasional bouts of impetigo eventually grow out of it. Owners of wrinkly skinned breeds may have to be more vigilant throughout their dogs’ lives, particularly where grooming and bathing are concerned.
From wounds to excess moisture, adult dogs who have loose folds of skin are more likely to suffer from recurrent impetigo. Solutions may involve specially formulated lotions or shampoos. Even in these cases, superficial impetigo is not a debilitating disease; a full course of treatment resolves within six weeks.