Parasites are potentially a health concern for ferrets, particularly in those that go outside, live with other pets that have access to the outdoors, or arrive in a new home from a less than ideal environment. Thankfully, most ferret parasites can either be prevented or treated with relative ease.
Coccidia are the most common intestinal parasites in ferrets. Infections in adults often do not result in clinical disease, but when young kits are affected, the disease can be fatal. Other less commonly diagnosed intestinal parasites include roundworms, hookworms, tapeworms, cryptosporidium, and Giardia.
Diarrhea, which may contain blood, is the most frequently observed clinical sign in ferrets with intestinal parasites. A veterinarian can examine a stool sample under a microscope, run any other additional tests necessary, and prescribe appropriate treatment. Sulfadimethoxine (Albon) is often used to eliminate coccidia in ferrets.
Ear mites and fleas are the most common external parasites in ferrets. Individuals become infested through contact with other animals (ferrets, dogs, cats, etc.) that carry the parasites or contaminated environments.
Ear mites cause ferrets to produce large amounts of thick, dark ear wax, scratch their ears, and shake their heads. Ear mites can be diagnosed by looking at a sample of material from the ear under a microscope or with a magnifying glass. Live mites are small and light colored and can be seen moving around, particularly on a dark background. A ferret with fleas will scratch at its skin more than normal, which may result in patchy hair loss. Fleas or their feces, which look like coffee grounds, may be seen with the naked eye on the skin of affected ferrets.
Topically applied selamectin (Revolution) is a safe and effective way to eliminate both fleas and ear mites from ferrets. Depending on a ferret’s size, one-half to one tube of the selamectin formulated for puppies and kittens less than five pounds may be used, but always ask a veterinarian first.
Ferrets are also susceptible to heartworm disease. Heartworms are passed to ferrets through the bite of infected mosquitoes, so heartworm disease is a particular problem in parts of the country where mosquito populations thrive for most of the year. Due to the small size of a ferret’s heart, as few as one or two worms are sufficient to bring about signs of heart failure, including difficulty breathing, weakness, pale or blue-tinged mucous membranes, abnormal fluid accumulations, and death.
Heartworm disease is difficult to diagnose and nearly impossible to treat in ferrets. Therefore, prevention is essential in at-risk individuals. Monthly application of selamectin (Revolution) is an easy way to prevent heartworm disease in ferrets. Ask your veterinarian about whether selamectin in an appropriate choice for your ferret and what the proper dose should be.