Why is my dog scratching so much?
Most vets have an extremely good understanding of canine dermatology (skin problems), but it can be daunting for the average dog owner to understand the terminology used. Because there are so many types of skin problem, the vet may arrive at several differential diagnoses (possible causes). In many cases, antibiotics are prescribed to treat infection, and steroids to help to bring down any inflammation and to make the dog more comfortable. This type of treatment is frequently enough to alleviate the symptoms and the dog experiences no recurrence. It is usually very successful in tackling flea allergic dermatitis (see below), alongside effective parasite control, and conditions such as wet eczema flaring up as a result of a bacterial infection. Difficulties may arise if the initial therapy is unsuccessful or the symptoms recur once the medication has finished. Thinking about the situation holistically, it makes sense to establish the root of the problem in order to prevent a recurrence and not just treat the symptoms.
The medical term for itching is pruritis, and this is governed by a scratch threshold. Primary causes of pruritis may include flea allergies, mites, atopy and food allergies. These are described in more depth later. Secondary factors such as stress, dry skin, pyoderma, bacterial infection or yeast infection can increase the pruritis. More than one diagnostic test may be necessary to determine all of the contributing factors.
The most common type of skin problem in dogs is flea allergic dermatitis, often abbreviated by vets to FAD (a condition where dogs are allergic to flea saliva and become very itchy following a flea bite). Whilst you would usually expect to see tell-tale signs in the form of “flea dirts” or the fleas themselves, sometimes there is no indication of their presence at all. It only takes 1 flea to trigger the reaction, and it may well have hopped off the dog leaving no evidence at all other than itchy skin. Flea infestations are easy to treat using a topical preparation on the dog (plus any other dogs and cats in the household). It is also very sensible to treat the environment itself, as eggs and larvae may lie dormant in carpets and soft furnishings for many years. Even if you don’t think your dog has fleas, it is a very good idea to use preventative treatment all year round especially if your dog is prone to itching.
Your vet may wish to perform skin-scrapings in order to look for microscopic ectoparasites such as mites. Although skin-scrapings are a useful and non-invasive means of examination, it is not unusual for the results to come back clear even if ectoparasites are present. Some types of mite may be buried deep within the epidermis and may not appear under microscopic examination if the scraping has not been deep enough. Others may dwell in clusters and therefore if they are not present on the part of the body from which the scraping has been made, then they again will not be evident under the microscope. Demodectic mange (the type of mange that some youngsters are born with) is sometimes very difficult to diagnose, unlike its more common relation sarcoptic mange (fox mange). Often the puppy / dog carries the mite, but only shows symptoms when the immune system is depressed. Sometimes it is sensible to treat for this, even if mites have not been detected.
Yeast infections such as Malassezia are another common cause of problem skin. This kind of condition is diagnosed by growing a fungal culture, and is characterised by a typically “yeasty” smell. The vet will prescribe an antifungal shampoo such as Malaseb. Treatment is very effective, but several applications are likely to be necessary.
Environmental allergies may also result in skin problems. Atopy describes an inhalant allergy, and includes reactions to pollen, dust and mould. Contact allergies include reactions to detergent and shampoo. The diagnosis of this type of allergy is by blood test or intradermal skin testing. The latter is a specialised procedure and is usually carried out by a canine dermatologist. If it is not a procedure offered by your own veterinary surgeon, you might wish to discuss the possibility of a referral to a skin specialist. When an allergy to a specific substance can be identified, the dog can be treated with hypo-sensitisation injections. Therapy is long-term (often life-long), but usually very effective.
Finally – some food for thought… Adverse food reactions may cause skin problems. You would typically expect a dog suffering from a food allergy or dietary intolerance to suffer from digestive problems, but surprising though it may seem – the skin and coat are often affected; frequently the ears and / or feet. Although it was previously thought that food allergies only occurred in older animals after a prolonged exposure to the reactive food ingredient, it is now widely recognised that these kind of allergies do indeed affect youngsters.
It is widely appreciated that fatty acids can improve coat condition. The Omega-3 fatty acids (found in fish oil) are very beneficial in the treatment of allergies of all kinds in dogs. They work in the skin to help reduce the amount and effects of histamine and other chemicals that are produced in response to the allergen. It may be several weeks or months before a significant improvement is noted, but they are very safe and are not associated with any harmful side-effects. Studies have shown that when Omega-3 fatty acids are used in conjunction with other treatments such as anti-histamines, in many cases, the use of steroids may be decreased or even discontinued.
Biotin (one of the B vitamins) is known to promote skin health. It is found in brewers yeast and is also very safe, with no known side-effects and has been found to greatly improve the condition of dry, itchy skin.
The entire Arden Grange range is supplemented with both Omega-3 fatty acids and brewers yeast. All Arden Grange products are free from wheat gluten, beef, soya and diary products – all of which may provoke adverse food reactions in the sensitive dog. They also contain no artificial colourings, flavourings or additives and are preserved naturally with Rosemary Extract and Vitamin E. The recipes are free from genetically modified ingredients.
For more information on feeding your pets call in and speak to one of the Scampers Petcare Advisors. We have found in many circumstances that a simple diet change to a high quality food like Arden Grange, that many skin problems can be helped or even completely solved.
Our thanks go to Ness Bird RVN of Arden Grange for her help with this article.
