Monday, January 25, 2010

The Ferret and Heartworms

Warning: Graphic Pictures Ahead

     Valentine’s Day is just around the corner and we think about the loved ones in our lives. This includes our fur children or in some cases feathered, or scaled.

     We want to think we are giving them all the love they need. This includes taking them to the vet for annual check ups or when they get sick or injured.

     We let ourselves think that only certain species get specific things, as only canines get heartworms. When the fact is that cats, ferrets, and in extremely rare cases humans can get this parasite.

     Just how does our beloved pet get this life-threatening infection? It starts with the bite of a mosquito. All this annoying little insect has to do is suck the blood of an infected animal taking several of the young heartworms known as microfilariae into its system where they become infective larvae usually within two weeks. It is these larvae that are passed into another animal by the mosquito taking another blood meal. This process takes approximately six months.

     The larvae travel through the host’s body for about three months some will mature into immature worms in the blood vessels of the lungs.

     Another three months will see this worms mature into their adult form where the will lodge themselves in the right side of the heart reducing its ability to pump blood effectively. This can lead to heart murmurs, fluid in the heart and lungs. 

     In five to seven months after the infection the adult worms mate and create new microfilariae that can cause the pet’s immune system to react which can cause damage to other organs and keeps the cycle continuing with another mosquito bite.

     Detecting heartworms in any pet can be done using a test called an IDEXX® snap test. This tests for several antigens (1) in the blood one of which is heartworms. It measures the protein on the skin of the adult female heartworm. If only male heartworms are present in the bloodstream, the test will show a false negative. Other tests that maybe included are x-rays, a complete blood count (CBC), and in some cases, an ultrasound of the heart.

     Dogs and cats may show signs of heartworms when they have 10 to 60 of them but it can take only one or two to kill a ferret. We, as pet owners, must be continuously learning about what can affect our small fur babies.

     Heartworms are under diagnosed in ferrets because not all vets are knowledgeable about ferrets or that they are susceptible to getting heartworms. The problem is not readily recognized because most ferrets that die are not necropsied (2) heartworm2_large


     Prevention is the key to keeping our pets free of these parasites. While the options are limited, there are two. One is ProHeart® an injectable heartworm preventable that is given every six month.

     ProHeart® is marketed and approved as a preventive for dogs but the Minor Species Act of 2004(3) allows for the use in exotics. The other recommended preventative is Advantage Multi® the makers Bayer™ have tested it in ferrets and found it to be a safe and effective treatment.

     Before starting any treatment, it is wise to have your fur children tested for any evidence that they may have been infective and discuss a course of treatment with your vet.


(1) Antigens: enzymes, toxins, or other substances, usually high in molecule weight, to which the body reacts by producing antibodies.

(2) Necropsied: Having the animal’s dead body examined.

(3) Minor Species Act of 2004

For more information you can go to the American Heartworm Society

I would like to thank,

Dr. Cottrell from West End Animal Hospital, FL for the use of the heartworm pictures and answering my questions.

Janet Tobiassen, DVM

Vet Loving Pets HB, DMV

1 comment:

Anonymous said...

so if a dog has a heartworm how do you get rid of them plzzz tell me i have two dogs with heartworms :(