Morwell Clinic 6 Hoyle Street
Morwell Vic 3840
Phone: 5133 8005  Fax: 5134 4077

Traralgon Clinic 180 Princes Highway
Traralgon Vic 3844 
Phone: 5174 5622 Fax: 5134 4077

• Ectoparasites• Infection• Allergies.

The Itchy Dog

Itchy dogs are one of the most common presentations veterinarians see in practice. Some breeds are particularly prone to itchy skin, such as terriers and poodles. There are three categories of common causes of pruritis, the itchy sensation.

ECTOPARASITES

These are little creepy crawlies that live on or in the dogs skin and feed off the blood, skin or skin secretions.

Fleas: Fleas are the most common parasite seen on dogs. They are most abundant during the warmer months and live both on the dog and in the dog’s environment (carpet, bedding and dirt). We also see fleas during the winter months as in house heating keeps the ambient temperature warm enough for fleas to hatch year round. Fleas bite the dog to suck blood, causing irritation and pain. Some dogs can develop allergy to fleas and will react dramatically to a single fleabite. Fleas commonly cause irritation around the dogs tail base, thighs and umbilical area, although very bad cases can have generalized irritation. Fleas treatments were revolutionised about 5 years ago, and we now have very effective “spot on” treatments available at the clinic. You may have seen “Frontline” and ” Advantage” advertised recently. These products should be applied monthly to prevent flea infestations. Our staff will happily demonstrate how to apply these products correctly.

Sarcoptic Mange: Sarcoptes mites live in the dogs skin, particularly around the eyes, ear tips, elbows and hocks. They can be spread from other dogs, or from wildlife, especially wombats. Mites can sometimes be detected by a skin scraping performed by your veterinarian, but are very difficult to find, as a single mite on your dog can cause a severe reaction. Your vet may suggest trailing treatment, such as “Revolution”, based on the clinical presentation.

Demodectic Mange: Demodectic mites live in the hair follicles around the face and feet. Localised infections in young dogs usually resolve without treatment. More severe, generalized infection may be treated under veterinary supervision with courses of ivermectin, antibiotics and medicated washes. Please note that ivermectin can cause serious side effects in dogs and should only be used as prescribed by your vet.

INFECTIONS

Infections can cause skin problems by themselves, but are more commonly seen as complications of other skin complaints. When the dog licks and scratches irritated skin it creates a perfect moist environment for bacteria and yeast to grow.

Pyoderma: “Pyoderma” is a bacterial infection of the skin and/or hair follicles. Pyoderma can be diagnosed by your veterinarian by taking samples from the skin and examining them under the microscope. Staphylococcus is the most common bacteria isolated from skin infections. Pyoderma responds very well to treatment with antibiotics. In many cases the infection is secondary to another underlying skin condition such as an allergy, in which case the dog may still be itchy after the infection has cleared. In these cases further investigation is required.

Malassezia dermatitis: “Malassezia” is a yeast that infects the skin, most commonly around the mouth, under the neck, feet and elbows. Like pyoderma, malassezia can be diagnosed microscopically from skin samples. Treatment options include shampoos such as “Malaseb” or oral tablets. Like pyoderma, malassezia can be secondary to an underlying condition, so if the itch doesn’t clear up after the initial treatment they will need to be seen again by your vet for further investigation.

ALLERGIES

Allergies occur when the body’s immune systems overreacts to a small stimulus. The dog must be exposed to the allergen (the cause of the allergy) multiple times for the immune system to become hypersensitive. If infectious and parasitic causes of itching are ruled out, then we need to investigate for allergies.

Contact dermatitis: Allergic contact dermatitis occurs when the dogs skin comes into contact with something that it is allergic to. Some things that may cause an allergic reaction include plants such as wandering dew (Tradescantia spp), strong bleaches and ammoniated floor cleaners. Contact dermatitis usually affects sparsely haired areas, where the skin is more exposed. The best treatment for contact dermatitis is long term avoidance. To try and determine the most likely source your vet will need a detailed description of your dogs environment. Patch testing can be used to confirm the suspected allergen.

Food allergy: Pruritis can be caused by a reaction to something in the dogs diet. The offending allergen is usually a type of carbohydrate or protein (chicken and beef are the most common). It is possible for your dog to develop an allergy to a food you have fed for many years without a problem, in fact, dogs need to be exposed to the allergen for a period before the body will develop a hypersensitivity.Food elimination trials are required to diagnose food allergy. You need to feed a new protein and a new carbohydrate for at least 6 weeks. There are suitable commercial diets available, such as Hills Z/D or Eukanuba Response Formula. Food trails must be strictly adhered to (no treats at all) and any coexisting infection treated during the trial period. If the dog responds to the trial, it should then be rechallenged with the original diet to see if the scratching can be reprovoked. Food allergy can then be confirmed and single ingredient rechallenges can be performed to identify the offending allergen(s).

Atopy: “Atopy” is an allergy to airborne allergens such as dust mites, pollens, moulds and insect debris. Dogs usually present with recurrent skin problems, which are often seasonal. Secondary infections are a common complication. There is no single test for atopy; it is diagnosed by exclusion of all other causes (treatment of infections, skin scrapings, food elimination trials).

Unfortunately, atopy is a lifelong disease that we cannot cure, however with careful management your dog can be kept comfortable. Management involves symptomatic therapy, avoidance therapy and immunotherapy (desensitisation).Symptomatic therapy relies heavily on the use of glucocorticoids, which can have serious long term side effects. We try to minimize the amount of glucocorticoids that your dog needs by using complementary therapies such as medicated shampoos and conditioners, antihistamines, and fatty acid supplements. These all have minimal side effects and can reduce the dependence on cortisone.Avoidance therapy and immunotherapy both require identification of the offending allergen. The most reliable method of detecting allergens is by intradermal skin testing. This needs to be done by a veterinary specialist in dermatology. We can arrange a referral for you to visit a specialist in Melbourne if skin testing is indicated.

IN SUMMARY  Pruritis is a common ailment that causes both dogs and owners a great deal of stress and frustration. To be accurate in our approach to treatment supplementary tests are often required, many of these can be performed in the clinic at the time of consultation. In many cases treatment trials may be used. In some cases the dog will be cured by the trial, but if the itching doesn’t stop, please report this to your veterinarian. The only way to diagnose some skin conditions is by a process of elimination. Many conditions will require lifelong management. Referral to veterinary skin specialists is available for more difficult cases.