An itchy dog is a stress for the whole family. When our dogs are uncomfortable, we naturally feel for them and want to relieve their signs as quickly as possible. Antihistamines, like Benadryl®, have historically been an easy over-the-counter option to provide people (and pets) some relief. Yet, studies have demonstrated that while antihistamines may relieve respiratory allergies in humans, they had little or no effect on skin allergies in dogs^[1,2].

Can Dog Itch Be Difficult to Treat?

Itchy dogs can be frustrating to treat — for the dog, the owner, and sometimes even the veterinarian. There are a variety of treatments that may be recommended for your itchy dog, including:

• Allergy medications to control itch and skin inflammation
• Anti-parasite treatments like oral or topical flea/tick preventatives
• Antibiotics or antifungals to treat the underlying skin infection(s)
• Topical therapy like shampoos, conditioners, and sprays for targeted treatment and to help keep the skin healthy

For uncomplicated itchy dog causes like fleas, treatment is easy to administer and can be up to 100% effective. For more complicated cases like dogs with seasonal or chronic allergies and secondary skin infections, it can be more challenging to completely eliminate the signs. However, there are treatment options available that can be used for the short-term and long-term management of skin allergies.

What About DIY and Over-the-Counter Options?

While it may be tempting to reach for the anti–itch shampoos and sprays at your pet supply store or to pick up an antihistamine at the drugstore, these may only provide temporary relief at best. Topical therapies may provide minor temporary relief in some mildly itchy dogs, but are not effective alone in controlling itch in most allergic dogs. Let your veterinarian know all of the current medications you are giving, as well as other medical conditions that your dog has, so they can make sure the prescribed medication is safe to use in your dog. They will work with you to identify the underlying cause of the allergic itch and make an individualized treatment for your dog and your lifestyle.

What are Antihistamines and Why Don’t They Work for Most Itchy Dogs?

Allergies in dogs are different than allergies in people. Histamines cause upper respiratory allergies in people, whereas cytokines (not histamines) cause skin allergies in dogs.

For dogs with underlying skin allergies, antihistamines don't control the cytokines (signaling proteins) that cause inflammation and itch^[1]. In fact, the International Committee on Allergic Diseases of Animals lists antihistamines under "Interventions likely to be of little or no benefit to treat acute flares of canine atopic dermatitis^[3]." Antihistamines can also cause some unwanted side effects, including sedation, trembling, and panting^[4]. In addition, antihistamines can put your dog at risk for worsening allergic itch and secondary infections since they are not treating the underlying cause of the skin allergies.

Alternatives to Treating Itchy Dogs with Antihistamines

Work with your veterinarian to determine the underlying cause of your dog's itch and discuss the best approach for relief, treatment, and prevention. For pet owners of allergic dogs, you'll work together with your veterinarian to find an anchor treatment (one single treatment that will control itch most of the time) and then supplement with other treatments depending on how your dog responds. If you are concerned about antihistamines not working in your allergic dog or side effects of antihistamines, ask your veterinarian about other targeted therapies proven to reduce allergic itch in dogs.

Managing your dog's itch quickly and effectively will save time and money, help minimize frustration, and best of all, give your pet the relief they deserve.