WORMS, FLEAS, DOGS AND HUMANS
Gretchen Irion has written some interesting documents for the Northern California Vizsla Club and for this Home Page.
My mother has always told me not to kiss my dogs for fear I would catch dog tapeworm. I have dutifully spent the last thirty years disregarding this advice, yet I have always wondered if it was true. I recently completed a Medical Parasitology course at U.C.S.F. as part of my pharmacy training and I would like to share my newfound knowledge.
The three main intestinal worms harbored by humans best friend are the dog round worm (Toxicara canis), the dog tapeworm (Dipylidium caninum) and the dog hookworm (Ancylostoma braziliense and caninum). Although unlikely, it is possible for humans to acquire some form of the three intestinal canine parasites. Generally children are the unlucky recipients due to an unrefined oral fixation.
The dog tapeworm is relatively non harmful to the dog. Occasionally, a child may acquire this intestinal parasite as well. This will not occur unless the flea that harbors the larvae of the tapeworm is ingested. Once ingested the larvae matures in the intestine and the adult will shed segments filled with eggs in the stool. These laden dog pies will eventually be eaten by fleas to complete the cycle. The infected individual whether it be human or canine is usually unaware he has ingested the tapeworm larvae unless white rice like proglottis are detected in the stool about a month later. This is not a dangerous predicament. (In fact, beef tapeworm were sold commercially as a diet aid in your grandparents day.) Eradication is straight- forward with a medication called praziquantil. This is not available at the pet store or Walgreens. You must visit your vet or doctor for the cure.
In flea season it sure is great to have a wash and wear dog with short hair. We usually see one or two fleas in May or June. An aggressive vacuum and a few cans of flea fogger a couple weeks apart usually do the job. If you experience lingering flea problems, it is nice to know some new products are on the market aside from the old standby of the pyrethrin or permethrin containing flea shampoo. Precor (methoprene) and Nylar (pyriproxifen) are insect growth regulators that affect the juvenile hormone release in the flea. These agents are in flea collars or topically applied to the infected dog. Insect development inhibitors such as Program (lufenuron) have recently been approved by FDA. Program interferes with the egg shell synthesis of the flea. It is conveniently given to your pet once a month. Advantage (imidacloprid) and Frontline (Fipronil) are newly released once a month topicals. Ask your vet if you have any questions.
If I may add a final trivial note on a different dog tapeworm (Echinococcus granulosus). The sheep dog tapeworm is not in fleas, but it can be dangerous to humans who become infected. Only dogs who are fed with raw sheep, moose or caribou lung, liver and brain harbor this parasite. The odds of your pet obtaining this tapeworm are virtually nil in modern day suburbia.
In the dog the roundworm is relatively benign and can be eliminated safely and easily by worming medication purchased at the pet store. Parentyl palmate is the active ingredient in Evict and some other brand names. This compound is in Heart Guard Plus (it is indeed the Plus) and can be given monthly safely in the adult dog or every two weeks when you first get your new puppy. (Always follow dosing directions given with the specific medi-cation). Ingestion of dog feces will not cause infection until a month has passed for the egg to mature. The problem occurs if you have infected dogs with children that eat dirt from the dog yard. (The biggest culprits are actually cats in the sand-box). The eggs of the round-worm are very sturdy and can live for years in the soil if they are not exposed to direct sunlight. The mud pie eater will not develop an intestinal infection. Instead, the lost larvae will wander around in the tissues and form a disease called VLM or visceral larvae migrans. Doctors have confused roundworm larvae in the eye for retionoblastoma which is usually treated by removing the eye. Removal of the eye is not necessary in VLM, but removal of the larvae is. A drug such as thiobendazole prescribed by your physician can eradicate the tissue parasite.
The hookworm is a nasty creature that can enter your body without being eaten. You need only walk barefoot on grass contaminated with feces to obtain this bugger. It can penetrate the skin. In the gut of the dog, the dog hookworm can cause blood loss almost like a bleeding intestinal ulcer. In a malnourished animal this can lead to anemia. However, the dog hookworm cannot mature in the human host. It does not find its way to the intestine. It wanders around lost like the dog roundworm in a human host but it doesn't get far. It is really lost. It remains just under the skin near the point of entry. CLM or coetaneous larvae migrans is the formal name, but you can call it the creeping cruds. Itching will occur as well as an elevation in a squiggly line pattern. The doctor can freeze this out just like a wart or you can scratch for two weeks and it will be gone. This parasite is prevalent primarily in warm moist climates.
Well, I've shared my limited knowledge with you. What do you think? Can you catch worms from kissing your dog? Not likely. It is a good idea to have your toddlers play in a separate yard from where your dogs usually do their thing. Check with your vet to be sure your dog is parasite free. It is also prudent to watch for signs of the rice-like tapeworm proglottis in your dogs stool. Use roundworm medications if you get a new puppy or if your bitch has recently had puppies. If your vet has put your dog on Heart Guard Plus you need only watch for tapeworm just after flea season because hookworm, roundworm and heartworm are already covered. Oh, and tell mom kissing is cool.