Feline Heartworm Disease

Feline Heartworm Disease

Canine and Feline Heartworm Disease share only one similarity…both are transmitted by the mosquito. Florida ranks first in the country for heartworm disease in both the dog and cat.
Past teaching in veterinary colleges was that when cats got this disease, it would cause only a transient illness and the patient would fully recover. However, over the past few years, research has shown about 30% of all cats either have been exposed or possess the disease. Indoor cats are more susceptible than outdoor cats to heartworms.
Symptoms include vomiting, asthma like symptoms, lethargy and poor appetite. In some patients however, there are no symptoms and death is sudden. In canine disease, as many as 50 to 100 worms may reside in the right heart ventricle and pulmonary arteries whereas cats may only have 1 to 2 worms in the lungs. Hence, a common symptom is an asthma like syndrome.
Currently, supportive care is the only treatment.Some patients will respond and recover and others will not. Unlike canine heartworm disease, testing is unreliable. Two tests currently available are the Antigen (detects heartworm material in the patient’s body) and the Antibody (examines the patient’s immune system for heartworm exposure). A positive or negative response to either or both tests does not rule in or out heartworm disease. In most positive tests cases, the patient has only been exposed to the disease and infection never occurred. Usually, further testing such as radiographs and bloodwork are required to fully assess the disease status.
Although there is no cure for this potentially deadly disease, there are two preventatives available: Heartguard (ivermectin) which is a chewable product given every 30 days that most cats dislike and Revolution (selamectin) which is a topical product also used every 30 days. Revolution not only prevents heartworm disease, but also treats fleas, ticks, ear mites, intestinal parasites and skin scabies. It is very easy to apply and should be used every 30 days. Unlike canine heartworm disease, Revolution may be used regardless of heartworm status. That is, the dog must have a negative heartworm test result prior to using prevention, whereas in the cat, it is not necessary.
If you have any questions to this puzzling disease, please don’t hesitate to call the clinic.

Canine Heartworm Disease

Canine Heartworm Disease

The Southern states rank first in the nation for heartworm infection (Dirofilaria Immitis). Florida is first among the southern states and therefore first in the nation for this deadly disease.
The mosquito transmits heartworm disease. This occurs by a mosquito obtaining a blood meal from an infected dog and then injecting the larvae in a non infected animal. Over a 6 month period, the larvae develop into adult heartworms and reside in the right side of the heart and vessels leading to the lungs. Adult heartworms begin to produce microfilaria (baby heartworms) which will also develop into adults in about 4 to 6 months. If the infection is allowed to continue, the dog will die from right sided heart failure or a complication thereof.
Diagnosis is quick and easy. The American Heartworm Association recommends an antigen (occult) heartworm test be performed once to twice yearly depending on location and incidence of heartworm disease. The antigen (occult) tests for adult heartworm protein in the patient’s blood. It takes 10 minutes and is virtually 100% specific. Ninety-nine percent of dogs with mature heartworm infection are antigen positive (have an infection). It is imperative your pet be tested at least yearly for heartworms even if you are diligent about giving prevention once monthly. Giving an infected pet heartworm prevention can be lethal and I have seen it occur throughout my career.
There are several heartworm preventatives on the market. Two products we carry are Heartgaurd Plus (Ivermectin/Pyrantel) and Revolution (Selamectin). Heartgaurd is a once a month chewable preventative for heartworms and also intestinal parasites. It does not provide flea or tick prevention. Revolution is the newest product on the market and is applied once a month topically to the skin. It provides heartworm, intestinal parasite, flea, tick, ear mite and skin scabies protection. As with all preventatives however, nothing is 100% effective and is why testing is necessary at least yearly.
We treat 5 to 6 cases a year for heartworm disease costing the owners $400 to $600 per case. Not only is it much less expensive to use a preventative, but also obviously better for your pet. If you have any questions regarding heartworm disease or prevention, feel free to contact the office.