Q I treat my dog for heartworm, but not my cats as I was told that cats were immune to heartworm. Is this true? If not, how do they get these worms? Can they catch them from the dog?
A Many people think that heartworms are a problem only for dogs, but heartworms can cause a serious disease in cats, only in a different way.
In cats the parasites cause lung problems and the condition is often misdiagnosed as feline asthma or allergies. Even totally indoor cats can get the disease because it takes only one infected mosquito to bite a cat and pass on the larvae in its saliva.
The larvae develop in the cat and enter the blood vessels as immature worms; they are carried in the bloodstream to the lungs, where they cause an inflammatory reaction. Many worms die at this point, causing an even more severe reaction. The surviving worms may live in the lungs undetected for one or two years. When they die they may cause a severe anaphylactic reaction that can be fatal.
The problem caused by heartworms in cats is called HARD, which is the acronym for heartworm-associated respiratory disease. Many cats show only mild clinical signs associated with a lung problem, but this can progress to a number of serious signs, where the cat loses its appetite with associated weight loss and lethargy, difficulty in breathing and coughing, vomiting and diarrhea, fainting, blindness, collapse, convulsions and death.
Cats can get heartworms only from the bite of an infected mosquito, not from your dog. Your veterinarian can recommend the latest heartworm preventives for your cat after a simple blood test to check whether your cat is infected. In the late 1990s a survey in Texas found 26 percent of the cats examined had antibodies to heartworms and 10 percent had adult worms present.
Q My new partner is upset that I let my two cats sleep in the bed with me, especially the one who sleeps on my pillow. He claims I can get all sorts of parasites from the cats and that it is unhygienic. I thought parasites were species-specific and would not spread from cats to people.
A There are many parasites that can be shared between people and cats. Perhaps the most common are fleas that are happy to hop from your cat to you and vice versa. If your cats go outside they can bring in ticks that can attach themselves to people. These ticks may be carriers of Lyme disease, which is becoming more of a problem with the upsurge in deer numbers and the associated increase in deer ticks.
Common roundworms can cause problems, especially in pregnant women and children. It is estimated that 3 million to 6 million people become infected with roundworms each year. Most kittens will contract roundworms from their mother's milk, so it is important that they are dewormed as soon as they are old enough.
Infected cats pass the worm eggs in the feces. Good hygiene is important with regular hand-washing and daily scooping of the litter tray. Avoid feeding your cats raw meat and be aware that your cat can become infected by eating various prey.
Your veterinarian can advise you on the correct and best types of parasite-control measures.
There are a number of other parasites that can infect people but are much less common. These include hookworms, which are present in the soil and enter through the skin. This is another reason for not allowing children to run around barefoot in the dirt. People are not the primary hosts for heartworms, but they can occasionally become infected from a mosquito bite. Tapeworms are spread by the bites of carrier fleas. There have been some reports of ear mites spreading from a cat to its owner, especially when the cat is allowed to sleep on the pillow.