Jill Bowen

Jill Bowen has practiced veterinary medicine in England and Texas and has taught at Texas A&M. She lives with her veterinarian husband and two cats in Blacksburg. If you have a question, please write to her in care of The Roanoke Times, P.O. Box 540, Christiansburg, VA 24068, or send an e-mail to mjbowen@radford.edu

Recent columns

• Invisible fences aren’t best option for every dog
• Wrap pets in protection this holiday season
• Take treats so horse associates you with something good
• Illness or change in environment may cause cat to stop using litter box
• Column archive

Now that the weather has turned warm at last, I suppose that flea season is just around the corner. I normally buy my flea control products from my veterinarian, but many of my friends use over-the-counter products and I wondered what you thought of them?

Over-the-counter flea and tick manufacturers have produced a crowd of new spot-on remedies, particularly for cat owners, who have been somewhat neglected in the past. Two of these new products contain etofenprox, a relatively new adulticide that, when combined with an insect growth regulator, repels and kills fleas, ticks and mosquitoes.

These products are cheaper than those dispensed by veterinarians and are a viable alternative. However there is no substitute for your veterinarian's guidance on which product is the most suitable for your pet and how to use it correctly.

This is particularly important for very young animals and also the old or debilitated. Never use products that are formulated for dogs on cats, because they are too strong and could cause an adverse reaction in the cat.

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Why do cats not get heartworms? We dose our dogs monthly but ignore the cats. Should we dose the cats? Or maybe they don't get them.

Cats are resistant to heartworms, although they can become infected in some instances. The incidence in cats is rare in many areas but not in heartworm endemic areas such as the Gulf Coast of Texas and other states along the Gulf of Mexico, as well as South Carolina and Tennessee.

Ten percent to 20 percent of cats may be infected in warm, humid areas where mosquitoes and heartworm disease flourish. Many veterinarians in these areas recommend that cats should be on preventative medication. Products containing ivermectin or selamectin are marketed for use in cats.

For a cat to get heartworms there must be a reservoir of infected animals, usually dogs, as well as plenty of mosquitoes. More than 50 species of mosquitoes can transmit heartworm, but not all of them readily feed on both cats and dogs.

If a cat does become infected it takes seven to eight months for the larvae to become adults in the heart. However, signs of disease can occur much earlier. To reach the heart, the infected larvae pass through the cat's blood stream via the lungs and can cause intense inflammation. This causes the cat to show signs such as coughing, gagging, vomiting, asthmatic breathing and appearing ill, or there may be no symptoms at all, yet the cat dies.

A definitive diagnosis of heartworm in cats requires quite a barrage of tests. Fortunately, heartworm in cats is rare in this area. Be wary if the cat once lived in areas where the disease is more prevalent or if the cat lives with dogs that are not on a regular heartworm regimen, as dogs are much more susceptible to heartworm infections.

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A note of warning: Now that coyotes are being seen with a greater frequency in our area, please be careful if you notice any that are behaving out-of-character. Normally coyotes, like other wild animals, will run away at the approach of people; those that don't run or appear aggressive could be rabid. Last fall a coyote tested positive for rabies in Pennsylvania. This coyote had attacked two dogs and attempted to get into the house before being shot by the homeowner. There have also been several cats that have tested positive for rabies in our area in the past year or so.