Many dogs suffer from an itchy skin. This itchiness can be triggered by a variety of causes. It is very important to follow a stepwise approach to eliminate the possible causes of the itching. Determining the cause can be a time-consuming and complicated process, due to the fact that multiple factors can play a role. Treatment is often symptomatic and most pets require lifelong treatment.

Process of elimination to determine the cause

Itching and scratching causes a vicious cycle. Your pet can start itching due to various causes, followed by scratching. This scratching causes skin damage, which results in more itching and scratching. Secondary bacterial or fungal infections can complicate the skin disease.

As stepwise approach is critical to determine the cause of the itchiness. Firstly, the easy to eliminate causes should be treated, such as parasites.

Flea bite allergy

Many dogs are allergic to the saliva of fleas. Dogs with flea bite allergies are often especially itchy on the “pants area”. This area consists of the tail-head, lumbo-sacral area (lower back area), ventral abdomen and inner thighs. The dogs often display hair loss, signs of self-trauma, redness and increased pigmentation. It is sometimes difficult to find fleas on the dog and fleabites can continue to itch for weeks after the bite. Prevention is very important, therefor effective and consistent flea treatment should be applied. Various options are available such as chews, spot-on and collars. Environmental treatment should also be utilized to prevent flea eggs from hatching. 

Parasitic skin diseases

Mange and lice can cause severe irritation to your pet. The skin irritation is typically concentrated around the ear pinna, face, elbows, hocks, feet, chest and abdomen. A skin scrape is often diagnostic, where the parasites are visualized under the microscope. Treatment and prevention have recently become easier and more effective through the development of longer acting chewable and topical parasite treatment. Treatment should span a period of at least two months, as the lifecycle of the mite in the environment is up to a period of 21 days.

Ringworm is not actually a worm, but caused by a fungi (dermatophytes) that grows in the superficial layers of the skin. The lesions mostly have a typical ring like appearance. Ringworm treatment consists of an intensive treatment regime, including topical creams, washing with medicated shampoos and oral anti-fungal drugs. The environment, collars and bedding should also be cleaned thoroughly.

Various parasitic diseases are zoonotic, meaning that both humans and animals can become infected with the parasite.

Food allergies

Dogs are normally allergic to proteins, especially chicken, beef and lamb. Dogs are rarely allergic to grains. Dogs with a food allergy are especially itchy on the abdomen, inguinal area, axillae, face, ears, or feet. The only accurate method of diagnosis is a food trial of 8 to 12 weeks. During this time the dog should be fed a diet consisting of novel proteins (proteins the dog has not eaten before, such as duck or fish) or a hydrolyzed protein diet (proteins are broken down to small peptides). The dog should not receive any treats, flavored chews or table scraps during this trial period. If the itchiness decreases during the food trial, then a food challenge should be started after the 8 to 12-week period. Either the previous diet, ingredients of the diet or certain treats can be fed for two weeks. If the itching starts again then the food trial should be re-started. Once the culprit protein is identified, it should be avoided permanently.

Atopy

Approximately 50% of itchy pets suffer from atopy, where the itchiness is caused by environmental allergens such as grass, pollens or house dust mites. These dogs tend to be is particularly itchy in the face, ears, abdomen, inguinal area, or feet. Atopy normally only starts between the age of one to three years. Allergens enter your pets’ body through a compromised skin barrier.

Pets with atopy will sometimes show a seasonal reoccurrence of itching skin. When washing the floors at home, rinse with water afterwards to decrease the amount of chemicals on the floor. Fabric softeners can sometimes cause skin irritation, therefore avoid using them and wash blankets with an extra rinse program. Supportive treatment is important and will be discussed below. Life-long treatment is often necessary.

Hot spots

Bacterial infections of the skin cause pyotraumatic or moist dermatitis commonly known as hot spots. This bacterial infection often takes hold after the skin barrier has been damaged. This can be caused by excessive moisture (such as swimming), trauma (such as scratching), foreign bodies (thorns, insect bites), allergies, fungal infections or endocrine diseases (hypothyroidism). This results in a red, moist, oozing, itchy area of skin. Treatment consists of shaving and washing the hot spot and applying topical creams.

Management of an itchy dog

• Anti-inflammatory or Immunosuppressive medication
  Most commonly corticosteroids will be used. Cortisone often results in an immediate relief of itchiness. However, cortisone is not a wonder drug and should never be used long-term. Short term side effects include an increase in thirst, urination and hunger, as well as a decrease in energy. Cortisone should not be used to treat fungal infections, as it can make the infection worse. Diabetic dogs should also not receive cortisone. Long-term use can result in urinary tract infections, thinning of skin, poor wound healing, muscle weakness, obesity and even Cushing’s disease when the body is overproducing cortisol. Suddenly stopping corticosteroid treatment can result in Addison’s disease, where the body is unable to produce its own cortisone.

• Anti-histamines

Anti-histamines that either contain loratadine or chlorpheniramine can be used to relieve allergy symptoms in dogs. Less than 30% of dogs have a satisfactory improvement of clinical signs on antihistamines, therefore they are often combined with other treatment regimes.

• Topical treatment
  Creams, sprays or shampoos containing cortisone, antibiotic or anti-fungal agents can help with treatment. Creams and sprays are effective to treat localized areas.

• Essential fatty acids (Omega 3 and 6
  These oils help to strengthen the skin barrier of your pet, decreasing the likelihood of environmental allergens entering the skin. Furthermore, they decrease the inflammatory reaction of your pets’ skin. These oils can be used long-term and do not have any adverse side effects. The use of essential fatty acids does not produce immediate results, but takes at least two months to show a beneficial effect.

• Apoquel
  This medication provides a fast relief to itching. Apoquel targets specific small proteins(cytokines) that cause itch and inflammation in allergic dogs. This medication has few side effects and can safely be used long term.

Determining the cause of the itch in your pet can be very time-consuming. However, it is definitely worth trying to find the cause of the itchiness and managing it successfully. Lifelong management and treatment are often necessary in an itchy pet, especially when your pet suffers from atopy. If treatment is stopped the skin disease will flare up, requiring higher dosages of medication to control it again.

Please contact us for more information.

Sources

• Ettinger and Fieldman, Textbook of Veterinary Internal Medicine, Client Information Sheet, Atopy and Food Allergies
• Itchy skin, fact sheet Efazol 2018
• Miller, WH et al. Muller and Kirk’s Small Animal Dermatology, 7th ed
• Apoquel (oclacitinib tablet) https://www.apoqueldogs.com/apoquel-can-help.aspx