Skin Infections in Rodents

Skin infections can affect many different animals and our small pets are no exception. The skin is composed of many different layers, and although every layer can potentially be affected by infection, the majority of cases involve infection of the more superficial layers of skin. These superficial skin layers can easily be invaded by microorganisms such as bacteria, fungi or parasites, that are not normally found there.

All species of rodent can be affected. Those hairless species (e.g. “skinny pigs”)are potentially more at risk as they lack the protection against injury that hair can provide, meaning wounds can occur more readily. This is a primary route by which bacteria can enter and cause infection. In a similar situation, rodents with other diseases which cause thinning of the skin, such as hormone imbalances; or itching and scratching of the skin, such as external parasites like mites, could also leave themselves open to problems.

All animals carry bacteria on the skin as normal commensals (harmless passengers), but the skin is a great barrier to infection. So skin infections will only occur when there is an upset in this balance, either due to: an overgrowth of bacteria or yeasts on the skin

Parasitic infections are slightly different in that the causal agent – the parasites - are not present normally, nor do they need a change in the skin’s defences to cause a problem. Parasites can happily live on healthy skin so often all it takes for an infection to be established is for the rodent to be exposed to the parasite.

Fungal infections are responsible for the condition known as ringworm which occurs when the animal is exposed to the fungus on contaminated objects or by direct contact with an infected other.

To some degree, it depends on what and where the infection is as to what clinical signs can be seen but in general, common symptoms include:

• itching
• redness
• hair loss
• crusting
• spots
• dryness or flaking

The classic appearance of ringworm is that of a crusty, red ring-shaped lesion but it doesn’t always look like this, and is sometimes known as the “great imitator” as it can also cause any of the symptoms listed above either as well as, or instead of, it’s classical ring-shaped mark.

In general with skin infections, animals may behave fairly normally, but in some cases they may become lethargic, seem in discomfort or go off their food.

Many cases of skin infections can be diagnosed by appearance alone. However, in order to determine what the cause of the infection is, further testing may be required. This could involve your vet taking skin scrapes, hair plucks, sellotape strips, swabs or occasionally biopsies.

Treatment will depend on the cause. For bacterial or fungal infections, the vet may prescribe a topical treatment, such as shampoos, creams or sprays; or a systemic one, with liquid or injectable antibiotics, anti-inflammatory or painkilling drugs. Parasites can be treated with parasiticides, which are often available as a spot-on. For some infections, treatment may need to be prolonged, lasting several weeks or even in some cases months.

Skin infections are highly unlikely to lead to any severe complications. They can be uncomfortable and frustrating to treat, especially if multi-factorial, but rarely dangerous if treated early. If there is a large area of severe skin damage, sepsis could be a potential concern, or a heavy parasite load can be fairly debilitating or lead to anaemia, or even (in rare cases) seizures.

Being vigilant for any wounds or breaks in the skin, keeping any such areas clean and monitoring for any of the signs of skin infection are the best ways to prevent any problems. Keeping the environment clean and using clean bedding will help to prevent parasites and fungal infections. Prompt veterinary attention if any symptoms of a skin infection are seen will ensure treatment can be started early on.