Because our southern winters are mild, we need to have animals on preventative all year long. Cats and ferrets can also get heartworms. This disease is not treatable in cats and ferrets, so prevention is crucial. There is now a heartworm preventative approved by the FDA for use in cats. While there is no preventative approved for ferrets, there are some options available.
Many exotic pets are much better at masking illness than dogs, cats or humans are.
This is because in the wild, an animal that looks sick is often lunch for a predator. So these pets typically do not show us they are feeling poorly until it is an emergency. If you wait, your pet may be too sick for treatment. Here in East Tennessee we enjoy a fairly mild climate, avoiding the extremes of temperature more common in other parts of the country. While this makes a pleasant environment for us humans and our animal companions, it unfortunately also makes it pleasant for mosquitos and other pests.