The immune system is just as vital in our pets as in ourselves, to fight off illness and infection, and maintain our well-being. If your pet has recurrent infections, such as skin infections, ear or eye infections, or recurrent parasite infestations, these could be signs of a compromised immune system.

It Starts With Diet

What you feed your pet has a big impact on their general health, especially the immune system. This article from the Naturally Healthy Dog has some great information on diet, to ensure your dog is getting all the vital nutrients to maintain well-being.

http://www.thenaturallyhealthydog.com/?p=285

Exercise Helps

Especially for cats who live an indoor life - which is more common these days to protect wildlife from the cat's natural predator instincts - providing a stimulating environment that encourages the cat to exercise is very important to overall health and a strong immune system. 

This great article from The Daily Cat outlines four simple ways to support your cat's immune system through lifestyle.

http://www.thedailycat.com/health/illness/how_to_strenghten_cats_immunity/index.html