My dog, Freda, has demodectic mange. Her doctor recommended dipping her to control the mange.

I would also like to use supplements to help boost her immune system since the doctor told us the reason she has mange is because of a bad immune system.

Is there anything you can recommend?

Using nutritional supplements to boost the immune system in times of illness is very important for any sick pet.

Antioxidants are among the most commonly used supplements to help pets with a variety of medical disorders.

Antioxidants are specific vitamins (such as vitamin C and vitamin E) and plant and animal compounds (bioflavonoids such as grape seed extract, quercetin, co-enzyme Q-10, ginkgo biloba) that are responsible for maintaining health.

Technically, they do not boost the immune system but rather clean up the products of cell damage.

Antioxidants also decrease various chemicals that cause cell damage.

Because antioxidants minimize damage to cells, they are useful whenever disease is present and immune support is needed.

Echinacea is the most commonly known immune stimulant that also functions as an antimicrobial herb.

In people, echinacea is the No. 1 cold and flu herbal remedy. There are a number of classes of pharmocologically active chemicals in echinacea.

Arabinogalactans are polysaccharides mainly derived from the larch tree; studies have shown that these compounds may enhance natural killer cells and cause a release of interferon gamma. Arabinogalactans have strong immunity-stimulating and anti-inflammatory properties.

Purine nucleotides are another class of supplements that can be helpful for pets needing immune system support.

These compounds are involved in virtually all cellular processes and play a major role in structural, metabolic, energetic and regulatory functions. As with arabinogalactans, they have been shown to stimulate the activity of natural killer cells.

— Dr. Shawn P. Messonnier, author of the “Natural Health Bible for Dogs & Cats,” is a veterinarian and pet care advocate.