Allergic Skin Disease in Dogs – Understanding Itchy Skin



This article was provided to Pet Guardian Angels of America by Kevin Davies


Allergic Skin disease in dogs is a very complicated process and can easily be confused with other medical skin conditions. Always consult your veterinarian before starting any new treatment or modifying the current treatment for your pet.

This article will help you understand the most common causes of skin allergies in dogs and some of the most popular treatments and remedies. Some remedies can be purchased over the counter; some require a prescription from your veterinarian.

What is an allergy?

The immune system is constantly looking for potentially harmful bacteria and viruses. When it encounters them, the immune cells remember what that bacteria or virus “looks like.” Then special immune cells produce chemicals that will stick to the bacteria or virus if they come in contact with it. These special chemicals are called immunoglobulins. If an immune cell circulating in the body comes in contact with a bacteria or virus that has these chemicals stuck to them, the immune cell ruptures releasing potent histamine chemicals intended to destroy the object. These histamine chemicals and other chemicals the immune cell releases causes an alert to the rest of the immune system to mobilize and be ready. Histamine is a potent inflammatory chemical and causes swelling, redness, and itching. Normally, this is good, because it helps the body defend itself against harmful bacteria and viruses. However, sometimes the immune system produces immunoglobulins that stick to harmless things. Things like: pollen, dander, dust mites, flea saliva, grasses, fabrics, tobacco smoke, beef, lamb, rice, corn, etc. When this happens, allergies occur. The immune system is attacking harmless things, but instead of protecting the body it causes scratching, itching, breathing problems, and potentially fatal reactions.

Why do dogs usually scratch with their allergies?

It is easy to understand why fleabite allergy develops itchy skin, but how do allergies to things in the air cause my pet to scratch? Immune cells that contain histamine granules and other inflammatory chemicals rupture when they come in contact with the substance that causes the allergy. When this happens in the skin, it causes intense itching. It is unclear in dogs and cats whether the allergic substance travels from the air through the skin, or from the air through the lungs and through the bloodstream. It is probably a little of both.

What can I use to control my dog’s allergies?

Essential Fatty Acids – Essential fatty acids are thought to help by binding to some of the inflammatory chemicals in the body. This reduces the itching and also reduces the number of immune cells that will migrate to a reaction site. It takes about 2 ½ months to notice a difference in the level of itching after starting essential fatty acids. Great sources of essential fatty acids include: Aller G-3 Caps (3V Caps equivalent), and Actis Omega for Dogs or Cats (3V Liquid Caps equivalent). The Aller G-3 Caps (3V Caps equivalent) can be punctured and squeezed onto food, or given like a pill or capsule. Actis Omega for Dogs or Cats (3V Liquid Caps equivalent) can be pumped onto the food straight from the bottle. Generally speaking, dogs that are easy to administer medicine to are placed on the Aller G-3 Caps (3V Caps equivalent), and dogs that aren’t and cats are placed on the Actis Omega for Dogs or Cats (3V Liquid Caps equivalent).

Shampoos – Dogs with minor and severe skin allergies will benefit from medicated shampoo. Sometimes, the allergies can be controlled with shampoos and medicated baths alone. The most common anti-itching ingredient in shampoos is oatmeal. As with most medicated shampoos, shampoos with oatmeal in them need to be in contact with the dog’s skin for over 10 minutes to be effective. Shampoos that have oatmeal in them include: Ectosoothe 3X, and Pramoxine Anti Itch Shampoo (Relief). Pramoxine Anti Itch Shampoo is primarily made for dogs with allergies and also contains Pramoxine HCl, another anti-inflammatory, and omega 6 fatty acids. Ectosoothe 3X is a medicated shampoo that kills fleas, ticks and lice.Premium Color Enhancing Shampoo is a whitener and brightener shampoo. Another anti-itching shampoo ingredient is salicylic acid. Salicylic acid helps remove built up dead skin and also is anti-inflammatory. Traditionally it is used with other ingredients to resolve skin problems. Shampoos that contain salicylic acid include: Sulfur Tar Shampoo (NuSal-T) and DermaBenSs.Sulfur Tar Shampoo and Derma BenSs are very similar shampoos in what conditions they treat on your pet. Sulfur Tar Shampoo is more beneficial for itchy dogs because it also contains menthol, and Derma Bens Shampoo is better for plugged or clogged hair follicles because it contains benzoyl peroxide.

Flea Control – Flea allergy dermatitis is one of the most common skin allergies in dogs. In some cases, one fleabite will set off a severe reaction. With flea allergies dogs chew over their hips near the tail, and the inside and outside of their hind legs. It can be severe enough to affect their entire body. Total flea control is the most important aspect in controlling flea allergy dermatitis in dogs or cats. The easiest solution for total flea control involves using a topical flea treatment such as Advantage or Frontline Plus.

Antihistamines – Antihistamines are relatively safe over the counter medicines that can help control allergies. Using just antihistamines will not adequately control moderate to severe skin allergies in dogs. The side effects of antihistamines include drowsiness and an upset stomach. Sometimes, antihistamines will cause dogs to become very excited and agitated. A strong word of caution: Do not use products that contain an antihistamine and another active ingredient. Other active ingredients can be harmful to your pet. Check with your veterinarian for the proper dose for your pet.

Prednisone – Prednisone is the most potent anti-inflammatory and anti-itching medicine. It also has some of the most severe side effects. It is usually reserved for dogs with moderate to severe skin allergies. Please consult with your veterinarian if you think your pet may need prednisone.

Cyclosporine – Cyclosporine is a relatively new medicine being marketed under the trade name Atopica. Cyclosporine has been used for some time in veterinary and human medicine for specific problems with the immune system. Cyclosporine is useful on dogs with skin allergies caused by things like pollen, grasses, dust mites, etc. It is not as effective against food or flea allergies. Common side effects of cyclosporine use include vomiting and diarrhea. Most of the time these side effects will subside with a reduced dose. More severe side effects can occur, but are rare. Long-term cyclosporine use is generally safer than long term prednisone use, making Atopica a good choice for dogs with severe chronic allergies. Atopica is expensive, and does require a prescription from a veterinarian.

Allergen Injections – Allergen injections are not to be confused with sustained released prednisone or medrol injections. They are injections made up of small amounts of specific allergens (the substance that causes the allergies). A company usually adds and mixes the allergens depending on an allergy test. Allergy testing can be done at a Veterinary Hospital or Veterinary Dermatology Clinic. Some Veterinarians prefer skin testing where small amounts of different allergens are injected in the skin. The injections that cause reactions in the skin are those that the dog or cat are allergic to. Blood testing can also be done. Blood testing is less expensive and less time consuming. In blood testing, the immune chemicals in the serum are brought in contact with the different allergens. Reactions in the serum are measured and graded

This article is written by Kevin Davies at