Itching dogs

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. The determination of the cause is a time-consuming process and sometimes the cause can never be found because multiple factors cause the itchy skin. Treatment is often symptomatic and most pets require lifelong treatment.

Process of elimination to determine the cause

Itching and scratching cause 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.

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

1. 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, lumbosacral area (lower back area), ventral abdomen and inner thighs. The dogs often have hair loss, signs of self-trauma, redness and increased pigmentation. It is sometimes difficult to find fleas on the dog, while fleabites can continue to itch for weeks after the bite. Prevention is very important therefore effective and consistent flea treatment should be applied. Various options are available such as chews, spot-on and collars. Environmental treatment should also be applied to prevent flea eggs to hatch.

2. Parasitic skin diseases.
Mange and lice can cause severe irritation to your pet. The skin irritation is especially on 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. However, treatment should span at least two months, while the lifecycle of the mite in the environment is up to 21 days.Ringworm is not actually a worm but caused by a fungus (dermatophytes) that grows in the superficial layers of the skin. The lesions mostly have a typical ring marking. Ringworm treatment consists of a more 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 diseases, meaning that both humans and animals can become infected with the parasite.

3. 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 did not eat before, such as duck or fish) or a hydrolyzed protein diet (proteins are broken down to small peptides). During this time the dog should not receive any treats, flavoured chews or table scraps. 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 or 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 then this should be avoided lifelong.

4. Atopy.
Approximately 50% of the itching pets suffer from Atopy. The itchiness is caused by environmental allergens, such as grass, pollens or house dust mites. The dog is particular 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 number of chemicals on the floor. Fabric softeners can sometimes cause skin irritation, therefor prevent using them and wash blankets with an extra rinse program. Supportive treatment is important and will be discussed below, while life-long treatment will be necessary.

5. Hot spot.
Bacterial infections of the skin cause pyotraumatic or moist dermatitis commonly known as hotspots. This bacterial infection often starts after the skin barrier was damage. 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 the skin. Treatment consists of shaving and washing the hotspot and applying topical creams

Management of an itchy dog

1. Anti-inflammatory or immunosuppressive medication.

Most commonly corticosteroids will be used. Cortisone often results in immediate relief of itchiness. However, cortisone is not a wonder drug and should never be used long-term. Short term side effects are an increase in thirst and urination, increase in hunger and a decrease in energy. Cortisone should not be used with fungal infections, while it can make the infection worse. Diabetic dogs should also not receive cortisone. The long-term use can result in urinary tract infections, thinning of the 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.

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

3. Topical treatment
Creams, sprays or shampoos containing cortisone, antibiotic or anti-fungal treatment 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 to enter the skin. Furthermore, they decrease the inflammation reaction in your pets’ skin. These oils can be used long term and do not have side effects. The essential fatty acids do not show an immediate result but take at least two months to show their beneficial effects.

5. Apoquel
This is a medication that relieves itch fast. Apoquel targets specific small proteins (cytokines) that cause itch and inflammation in allergic dogs. Currently, this medication is imported from America on a special permit, however, it is currently being registered in South Africa. 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, is definitely worth trying to find the cause of the itchiness and to manage an itchy pet successfully. Lifelong management and treatment are necessary for 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
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