Allergy Treatments

A wide variety of possible treatments for allergies exist. Most of these treatments differ widely in their effectiveness from patient to patient and often several of these treatment approaches must be combined to obtain sufficient relief for the patient. Usually a great deal of experimenting by the owner is necessary to find the combination of treatment that works best for a given pet. Therefore, caring for a pet with allergies often requires a great deal of patience, persistence and expense.

We should also note that often other ancillary treatment is needed such as drugs for secondary bacterial or yeast infections of the skin and particularly the ears. Testing for concurrent hypothyroidism or ther conditions may also be recommended. Usually a patient with severe allergy problems must be re-evaluated at least every six months.

Side effects of medications are a consideration as well. This is especially true for patients with year-round allergies (non-seasonal allergies).

A brief introduction to the different treatment options are:

1. Identification of the offending allergen(s) and preventing patient exposure

This is the best treatment since it involves no medication and usually minimal expense. However, it is often extremely difficult. One reason for this difficulty is that many patients with allergies are allergic to many different things. Deprivation trials are the only way to reliably diagnose specific agents of allergy. This means a trial where the patient is not medicated and the patient is prevented from exposure to the suspected agent (allergen) and the patient is observed for a minimum of 4-6 weeks to see if improvement results. A common deprivation trial we recommend involves feeding a diet that contains totally different ingredients than the one the pet has been eating to see if the problem is primarily food allergies. Click here for more information on diet trials.

2. Cortisone (Many different brand names and types)

This is the most effective and predictable agent to treat allergies. It is relatively inexpensive. However, the potential side effects of cortisone are major drawbacks to it's use, especially for long term treatment. It is safest when used for a seasonal (occasional) allergy. It is usually given as an oral tablet but severe, acute allergic cases may need an injection. The most common side effects are increased appetite (leading to obesity) and thirst. More serious and even life threatening side effects are possible. The lower the dose and the less frequent the dose, the less the potential for side effects; but, there is no such thing as a risk free dose of cortisone. Despite the risks, cortisone use is often still necessary to control symptoms in many patients and the other medications mentioned below are often used to try to reduce the dose or frequency of cortisone use.

3. Antihistamines

Histamine is not as an important a part of animal inflammation as it is in human inflammation so antihistamines are often less effective in animals. However, they occasionally can make a noticeable improvement in certain individuals especially when combined with fatty acid suplementation (see below). Only one antihistamine should be given at a time and if no improvement is noted after 7-10 days it should be discontinued. Antihistamines may cause either drowsiness or excitement in animals. They must not be used in animals that have seizures, are pregnant, have liver disease, or have glaucoma. The following are antihistamines available over-the-counter.

For dogs:

• Diphenhydramine (Benadryl): 0.5 to 1.0 mg per pound up to 3 times daily
• Clemastine (Tavist): 0.05 to 0.1 mg per pound up to twice daily
• Chlorpheniramine: 1 to 2 mg (total dose) for a small dog, up to 4 mg for a large dog, given up to twice daily

For cats:

• Chlorpheniramine: Give 2 mg per adult cat (total dose) up to twice daily
• Clemastine (Tavist): Give 0.68 mg (1/2 of a tablet) total dose up to twice a day. Note: you must not use Tavist D as it contains a decongestant that is toxic to cats!

4. Fatty Acids

Certain fatty acids have been shown to have a mild anti-inflammatory activity. These are nutritional supplements that are derived from fish oils and are not drugs. "Derm Caps" and "EFA Caps" are examples of fatty acid containing products marketed through veterinarians. We rarely find that they are sufficient in themselves to control allergies but combined with other treatments they often help. They must be given for at least 3 weeks to evaluate their effectiveness for a given patient. Less effective are the plant source fatty acids (1 to 2 teaspoons on the food daily).

5. Amitriptyline (a prescription antidepressant)

In some patients the reduction in itching can be substantial with this medication. It can cause some drowsiness (usually temporary) and must not be used if the patient has heart disease.

6. Topicals

This includes cold water baths, colloidal oatmeal, skin moisturizers like Avon Skin So Soft, hydrocortisone cream or lotion, benadryl cream, etc.). These can treat minor contact allegies effectively and often are helpful combined with other treatment modalities.

7. Allergy testing and hyposensitization injections

This service is usually used for inhalent or contact allergies. This involves referral to a dermatologist and takes several months to evaluate its effectiveness. This can be expensive, but is a great option if it works. Unfortunately, only about 50% of the patients get significant improvement. There is a very small chance of a life threatening "anaphylactic" reaction to the injections.