KAREN TODD-JENKINS, VMD
Itching can make pets absolutely miserable, but it is actually a sign of an underlying problem. For example, if the pet has an allergy, exposure to the allergen causes a series of events to happen within the animal’s body. Part of this series causes certain cells in the pet’s skin to release chemicals called histamines. When released into the skin, histamines are very irritating and lead to itching. (Histamines are also involved in allergic reactions in people.) Medications that target histamines are called antihistamines. However, histamines are only part of the story.
In pets, allergic reactions also cause the release of several other chemicals that contribute to irritation, inflammation and itching, but antihistamines can’t counteract the effects of all of these other agents. Scratching makes the skin susceptible to bacteria and fungal organisms, which also release chemicals that irritate nerve endings in the skin and cause itching. If an itchy pet doesn’t respond to an antihistamine, it may be because histamines are not playing a large role in the itching that the pet is experiencing.
Less commonly, some animals chew or lick themselves excessively as a compulsive behavior, usually as the result of stress. These kinds of behaviors are caused by the brain and are called psychogenic behaviors.
All of these factors are important when considering therapy for itching. Some pets with allergies can do fairly well just on antihistamines, but most other pets need other interventions to help control the problem.
What to Watch For
The clinical signs associated with itching can be mild or very severe:
- Twitching the skin
Some pets may seem generally agitated, stop suddenly while walking to turn around and scratch, or whine as they are scratching. Scratching can quickly lead to skin damage, bleeding, hair loss, scabs, and secondary skin infections with bacteria or fungal organisms.
How is the Cause of Itching Diagnosed?
Itching is a response to another condition, so identifying the cause is as important as treating the itch. Your veterinarian will likely begin the process with a complete medical history and physical examination of your pet. Your veterinarian may also recommend diagnostic testing that can include:
- Combing your pet to look for fleas
- Taking samples of hair and skin cells to look for mites and other skin parasites
- Culture testing to identify bacteria or fungal organisms
- Allergy testing
- Blood work to look for underlying medical issues that can affect the skin
If the problem has been chronic or recurring, your veterinarian will likely ask about what therapies have been tried in the past and if they were successful. This history can provide critical information about the nature of the underlying problem.
How is Itching Treated?
Managing an itchy pet can require several approaches, because there may be multiple contributing factors. For example, if a pet has an underlying allergy that is complicated by a flea infestation in addition to a bacterial or fungal infection, all of these may need to be addressed. In this situation, be sure to clear up any questions about your pet’s diagnosis or therapy to minimize confusion and frustration during treatment.
Treatment for an itchy pet can require a long-term commitment. Because pets respond differently to medications, your veterinarian may need to revise the treatment plan as therapy is progressing. It is important to maintain communication with your veterinarian, especially if a treatment doesn’t seem to be helping, or if your pet seems to be responding negatively to that treatment.
- Topical products: Your veterinarian may recommend a topical product if your pet has mild or localized itching, or as supportive therapy for more generalized conditions. Examples may include moisturizers, ointments and lotions. These products may need to be applied frequently (sometimes several times daily) to help ease itching. Be sure to follow all label directions and consult your veterinarian with any questions.
- Shampoos: Medicated shampoos can help some pets suffering with itchy skin. The effects of medicated shampoos may last for a few days; some shampoos can be used along with a leave-on conditioner to extend the effects. If you are unable to bathe your pet, another option should be discussed.
- Medications: For many pets, corticosteroids (steroids) provide more relief from itching than many other forms of treatment. Many products are available, and they can be given as pills, liquid or by injection. However, corticosteroids have some side effects and not every pet is a candidate for this treatment. Your veterinarian will evaluate your pet and determine if corticosteroids are the right option. Some pets with itching do well when given antihistamines, and if your pet has a bacterial or fungal skin infection, medications are commonly used to treat those infections. There is also a formulation of cyclosporine that can help dogs with some types of skin allergies.
- Supplements: Fatty acid supplements and other nutritional supplements can help some pets with skin itching. However, various formulations are available using fish oils, vegetable oils and other combinations, and effectiveness can vary. Ask your veterinarian if a nutritional supplement can help your pet.
In some cases, therapies work best for a particular animal when they are combined. One pet may do very well receiving a combination of antihistamines with a shampoo and a nutritional supplement, while another pet may not. If your pet is not responding to therapy, contact your veterinarian to see if modifications are appropriate.
This article originally appeared in PetsMatter November / December 2011, published by the American Animal Hospital Association. Copyright © 2011 AAHA. Find out more.