Posted by Dr. Itch on 7/20/2017
Everyone seems to have heard that they shouldn’t bathe their dog often as it will remove their natural oils and result in dry skin. When you were growing up, your parents probably lied to you all the time: chubby man dressed in a red suit sliding down your narrow or non-existent chimney, scarily large bunny hiding hard boiled brightly colored chicken eggs, drunk (at least mine typically was) fairy flying under your pillow to take your teeth etc. etc. You can just add 'don't bathe your dog' to the long list of lies and scars that your parents inflicted upon you when you were young. As true for most wives’ tales that are passed down from generation to generation, there is a lack of scientific proof to support this claim. In fact, there is ample medical evidence illustrating the clinical benefit of frequent bathing for pet skin health. Bathing on its own can be quite soothing for a pet with allergies and itching. Routine bathing also has been shown to help spare the amount of other potentially harmful medications (including steroids) that your pet may need to control their itchy allergy symptoms.
Why does bathing help a pet with skin allergies?There are a variety of reasons why bathing can help a pet with skin allergies and itching:
- Allergen Removal. Common allergies in dogs and cats include things that are everywhere in the environment such as dust mites, danders, pollens and molds. Allergy symptoms in dogs have now been shown to be caused predominantly by percutaneous (through the skin) absorption. In other words, a dog or cat lays or steps on a potential allergen in the environment and absorbs it through the skin resulting in the allergic reaction and skin irritation/itching. This is very different from the main mechanism of allergy in people, which starts with inhalation. Because allergic reactions are triggered by absorption through the skin, bathing can be very helpful in that it allows for physical removal of the allergens from the skin. This removal prevents or dampens the allergic reaction and results in an improvement of allergy related symptoms such as itching. Because your pet can quickly be re-exposed to the allergens in the environment, the benefit of bathing is typically temporary and needs to be repeated frequently. Giving your pet a cool bath can be one of the best ways to quickly calm down an allergy flare and keep them comfortable.
- Reduction of bacteria and yeast on the skin. Bacterial and yeast infections/overgrowth are commonly seen in pets with skin allergies resulting in odor, crusting, redness and itching. Some studies report up to 85% of patients with skin allergies will have secondary skin infections when they present to their veterinarian. The incidence of resistant skin infections in dogs and cats is on the rise, and in some cases there are limited (or no) oral or injectable antibiotics that will work to kill the bacteria. In some patients, topical therapy alone must be used to resolve the infection. You can directly access the bacteria and yeast causing skin infections with topical treatments like shampooing. In most cases, you can achieve much higher levels of antimicrobials applied directly on the skin than you can ever achieve with oral administration, making topical therapies very effective for skin infections. In the day and age of bacterial resistance, it is best to avoid continued exposure to oral antibiotics as this has been shown to promote resistance. Relying on topical antimicrobial therapy is an effective method of both treating active skin infections and in preventing their recurrence.
- Moisturizing and improving barrier function of the skin. There is growing evidence that people and dogs with skin allergies have physical defects in the barrier function of the skin. These defects cause water loss from the skin resulting in dryness and also allow allergens to penetrate the skin. Frequent bathing has been shown to help hydrate the skin and restore a more normal barrier function, keeping possible allergens out.
How often should I bathe my pet with itching and allergies?Generally speaking, bathing for skin allergies is most effective when done at least once to twice weekly, or as directed by your veterinarian. The shampoo should be gently massaged and lathered into a damp coat. As a general rule you should allow a 5-10 minute contact time of the shampoo with the skin before rinsing well. Cool water is recommended as water that is too hot can actually exacerbate skin itching.
How do I dry my pet?After bathing and rinsing well, your pet should be towel dried. Drying with a hair dryer is typically not recommended. If a hair dryer must be used, then the cool setting should be selected as the heat can be drying, irritating and promote itching.
How do I choose a shampoo for my pet?The best way to choose a shampoo for your pet is by asking your pet’s veterinarian or veterinary dermatologist. There are a variety of shampoos on the market that vary with both active and inactive ingredients. For example, patients with recurrent skin infections generally benefit from shampoos with antimicrobial properties; your vet can help identify the type of infection that your pet has (yeast, bacteria) and choose the most effective topical agent. Future articles will review available topical pet shampoo options.
In general pets with allergies can be sensitive to certain active or inactive ingredients in shampoos. It is important to monitor your pet for any increased itching, redness, scaling or any new skin lesions after bathing, as these may be signs of irritation from the shampoo. If shampooing seems to irritate the skin, always discontinue and check with your veterinarian. In pets that are irritated by shampoos, you can attempt to gently rinse your pet with cool water as this will still allow for removal of allergens from the skin.
What about using my shampoo on my dog?The normal pH levels for human skin is on the acidic side (range 5.2 to 6.2) and human shampoos are formulated to maintain this balance. Dogs in general tend to have higher (more alkaline) skin pH. Skin pH does vary with the breed, gender, age and various other physiological and environmental factors. Given the differences in pH, it is recommended that you avoid any long term use of human shampoos for dog skin unless a particular shampoo is recommended by your veterinarian.
What about bathing a dog with normal skin?Dogs with normal skin can also be bathed regularly, but it is not required for normal skin health. The required frequency will depend on a lot of factors including environmental exposures and dirt/odor accumulation. In general, most dogs with normal coats can be bathed once monthly or more frequently if needed.
So dive right in and bathe your itchy pet.