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The Big Three Parasites - Fleas, Ticks and Heartworm

Pet Tales
by Barry B. Burtis D.V.M.

On a visit to South Africa a few years ago I had the opportunity to go on safari in Kruger National Park. Kruger is the largest game reserve in South Africa. It is roughly the same size and shape as Wales. It extends 350 km. (217 mi) from its north to south boundary and 60 km. (37 mi) from east to west. Our guide told us, on arrival,  that there would be no problem seeing lots of animals, but, one goal on our travels would be to attempt to spot all five of  the big five animals of Africa. The big five species are elephant, buffalo, rhinoceros, lion and leopard. There are many visitors to Kruger every year but you must be rather lucky to sight all five of the big five on your visit.

At this time of year, pet owners have to be on the lookout for the big three of animal parasites, in this part of the world. In this case, you and your pet must be rather lucky to avoid spotting one of these big three insect species that can cause such problems. The big three are fleas, ticks and mosquitoes. My advice to all cat and dog owners would be to take some action now against these parasites. If you wait to spot them it may be too late to avoid trouble.

Over the cold winter months, pets and their owners usually get a bit of a break in worrying about the big three. As soon as the warm days of spring arrive, though, they're back.

Fleas, in the various stages of their life cycle, winter on or near stray cats and dogs, pets that fail to get proper parasite control and various wildlife species. These days many of these wildlife species live in close proximity to us and our pets. Raccoons, opossums, squirrels, foxes, coyotes and skunks would be the most common species in our area that assist fleas to get through the winter. These animals quite easily live in and pass through the parks, neighbourhoods and yards where our pets live and travel. In the spring, fleas living on the parasitized wild animal soon lay the eggs and begin the cycle that will allow thousands of their offspring to begin to find a new host for themselves. Very often this host will be someone's favourite pet. Flea eggs hatch to become larvae, larvae enter a resting pupa stage and then hatch as young adults searching for that new host, where they lay some eggs and keep the cycle going.

Ticks can also be trouble for our pets. There are several different species of ticks that can bother dogs and cats. They are usually found in smaller numbers on a pet who has been infected. However, I once removed 78 ticks from a tiny little kitten, just a few weeks old that had been rescued as a stray. There are some ticks that can complete their life cycle on one host. However, many require two or three hosts. In colder climates, it may take one or two years to complete the entire life cycle. Rabbits and squirrels happen to be a preferred species for certain life cycle stages of certain ticks found in our area. Although historically it has been thought ticks are more a danger for pets in rural areas or those who go to a cottage or camp with their owners, this may not be quite as true as once thought. Again, the large number of wild animals, living in urban areas, is probably responsible for this.       
 When you spot a mosquito, you must remember the real danger with them is that they are the insect that spreads the dangerous heartworm parasite to our pets. It is just most unlikely that anyone will not see a mosquito or two in the next few months. It is very important that when you do see one, you can be confident that if your pet saw it first, your pet was not infected with heartworm by it.

In Kruger, we were very fortunate to see all five of the big five African animals. In fact, we saw a leopard, usually the most difficult to spot, within four hours of arriving in the park. Rhino were the evasive ones, hiding from us until the very last morning of our visit, just hours before we were to leave. I hope that you and your pet are equally lucky and avoid the sight of any of the big three parasites this year. However, please talk to your veterinarian now about how to protect your pet from the big three that pose a danger to them.