Dewormings come in pairs.
Deworming medication can kill only adult worms, so if your pet is diagnosed with hookworms, whipworms or roundworms, common intestinal parasites, treatment must follow the proper schedule in order to be effective.
If the “first deworming” is given today, the “second deworming” will usually be administered in 2-4 weeks. In that time period the worms that are immature today will become adults, making them susceptible to followup medication. In the case of puppies, second dewormings are usually scheduled to coincide with booster vaccinations.
An adult pet, however, may not need to return to the doctor for months, therefore second dewormings may be dispensed for home administration. Again, the schedule will be determined by your pet’s doctor, but usually will be in the 2-4 weeks range.
The next step is almost as important as the dewormings. Your veterinarian or his staff must perform a fecal flotation to determine whether treatment was successful. Usually a followup test is performed about four weeks after the second treatment. If the followup test is positive, another pair of dewormings will be necessary. A negative test usually means that your pet is “off the hook” until his next regularly-scheduled visit. Exceptions might include a pet predisposed to repeated intestinal parasitism or one with chronic gastrointestinal disease suspected to be parasite-related.
Treatment failure is not necessarily the cause of a positive test after two treatments. An adult pet may become re-infested from contamination of his own yard or trips to public areas such as dog parks and roadside rest areas. Puppies may clear the intestinal stage of a worm, but reinfect themselves from larval stages which reside in the fat tissues and muscle tissues of the body.
The after-test does not require that your pet make a trip to the veterinarian’s office. Obtain a stool sample not more than 24 hours old, then deliver about a tablespoon of it in a clean container.
Many heartworm preventives include ingredients that help to prevent intestinal parasitism. Interceptor, Sentinel, Heartgard Plus and Revolution are among those that help with intestinal worms. Revolution is labeled for intestinal parasite prevention only in cats.
Tapeworm treatment may follow a different schedule. While there are several species of tapeworms which commonly infect cats and dogs, a single treatment is usually effective in ridding the body of them.
“Worms” can infect other parts of the body in addition to the intestine. Heartworms, of course, are in the heart and lungs; lungworms (there are several species that infect cats and dogs) are mostly in the respiratory tract. Treatment for intestinal worms does not affect heartworms, and kills only certain lungworms. Certain tapeworms can also infect the liver.
As always, follow your veterinarian’s advice.
See you tomorrow, Dr. Randolph.