Why Does My Dog Scratch So Much?

'All that scratching is driving us crazy – can you give us something to stop it?' Unfortunately it's often not that straightforward. Itchy skin, scaly skin, patchy hair loss and thinning hair are just a few of the symptoms of skin disease. While some skin cases are simple to fix, others can be quite a challenge: the trouble with skin disease is that there are many possible causes, which can make investigation difficult, time consuming and costly!

What are the causes of skin disease in pets?

Causes of skin disease

Parasites, such as fleas and mites, are top of this list, but some other causes include bacterial infections, ringworm, environmental allergies, food allergies, hormonal conditions and skin cancers.

A good place to start is to ensure that your pet is on a good and effective anti-parasite treatment to protect against both fleas and mites. Fleas are very irritating and many animals have an allergy to flea saliva, so one bite can send them into a frenzy of scratching making the skin very sore and inflamed.

Mites will burrow into the skin surface or live in the hair follicles, damaging the skin and affecting hair growth. Many over-the-counter products only offer protection against fleas and even this protection may not be fully effective, so your vet may advise changing the product if there is a chance it may not be working well or not offering enough protection. It is also important to remember to apply the product according to the instructions as most products will need repeating at regular intervals.

If there is a bacterial infection present on the skin surface, this will need treatment. Infection can quickly spread and may make your pet itchy, and the process of scratching will cause further skin trauma and potentiate the spread of the infection. While treating any infection, your vet may also give something to help reduce the amount of scratching as it will certainly be driving your pet crazy too!

How do vets investigate skin disease?

Once good parasite control has been established and any infection has been treated, the next stages in investigation for those animals who are still having problems would be to take skin scrapes, hair plucks and skin biopsies. Skin scrapes and hair plucks are used to look for mites - if an animal has been treated effectively for these, then the skin scrapes should be negative.

However, ineffective or inadequate treatment may be detected by positive skin scrapes so the treatment plan can be altered. Hair plucks may also be cultured if ringworm is a possibility. The name 'ringworm' is misleading as it is actually a fungal infection of the skin, but early detection is important as it can spread quickly from one animal to another, and even to owners!

Skin biopsies involve taking a small sample of skin which is then processed and examined under a microscope for abnormalities. It can be used to detect bacterial and fungal infections, mite infestations, changes consistent with allergic reactions and skin cancers.

It can be tricky to spot skin conditions on dogs with longer coats, so make sure to check them over every few days for infection, fleas and sores.

At this point, your vet may also recommend taking a blood sample to check for any underlying disorders. Certain hormonal conditions in dogs, such as hypothyroidism and Cushings, can affect the skin and immune system making your pet more prone to skin disease.

The results of these investigations will determine what happens next - your vet will discuss the options with you. With luck, it may be possible to start a treatment plan, however, in some cases, an answer may still yet to be reached! Your vet may wish to implement a food trial if a food allergy is suspected, or may discuss allergy testing with you should an environmental allergy be a concern.

How can your pet avoid skin disease?

Good parasite control offering protection against both fleas and mites is very important to prevent the development of flea allergy dermatitis and mite infestations. If your pet likes to swim or frequently gets wet, dry them afterwards – warm, damp skin for long periods afterwards will predispose to skin infections. Try not to change your pet's food if the food they are eating suits them – switching foods may result in skin disease if the new food contains a different ingredient to which they are allergic.

Unfortunately, for some animals, skin disease will develop despite our good intentions. Some breeds of dog are known for their development of allergies so be sure to do your research if you are considering getting a certain type of dog. Whatever happens, if you notice your pet scratching more than usual or any other changes to the skin, try not to leave it to see if it will get better – it rarely will on its own, and will often become a much bigger problem!