Worms in your garden help aerate the soil and allow plants to flourish. Worms in your dog, on the other hand, serve no useful purpose and can severely compromise the health of, or even kill an animal if the infestation is heavy. The types of worms your dog's digestive tract may harbor depends on his age, your part of the country, and other factors, but the bottom line is that you want those disgusting invertebrates out.
Signs That Worms Are Leaving the Dog
Fortunately, there are many effective dewormers available for canine use. The type of dewormer used influences whether you'll see worms leave your dog's body. Some dewormers kill worms outright, while others paralyze them. It's the worms affected by the latter that you're most likely to see in stools or vomitus.
Sold under the brand names Strongid and Nemex, among others, pyrantel pamoate is a dewormer that works by paralyzing parasites, so you could end up seeing the results. It's one of the safest dewormers available, so it often is used for puppies. It is most effective at removing roundworms and hookworms, two of the most common worms in immature animals.
Signs of worms
You won't always see worms leaving the dog after a deworming. Viewing the nasty creatures as they emerge from your pet is the exception rather than the rule. You should, however, notice an improvement in your dog's general health and appearance, especially if the worm load was heavy. The Telegraph warns your dog may harbor worms if she has a scruffy, dull coat; a pot belly; loses weight for no apparent reason; butt scoots; frequently experiences diarrhea or vomiting; or has a ravenous appetite.
After a deworming, your dog's appearance and symptoms should improve. Don't use an over-the-counter dewormer for your pet, but take her to the vet so that the appropriate type of dewormer is administered. Your vet will likely recommend putting your dog on heartworm medication after testing to make sure she isn't already infected. Heartworm medication requires a prescription, but it eradicates most types of worms, not just those invading the heart. It's among the most effective ways to keep your dog worm-free.
Puppies and worms
No matter how well-cared for, puppies often are full of worms. If the mother wasn't dewormed regularly, she could pass them on to her puppies in utero or through her milk. As Canine Weekly notes, puppies in a litter will pass worms to each other, so if one puppy is wormy, it's a safe bet that so are all of his brothers and sisters. Regular deworming is part of basic puppy care.
After a deworming, puppies may vomit up worms if they are heavily infested. Your vet will put your puppy on a deworming schedule, with the second dose of dewormer generally given two-to-three weeks after the initial dose. Badly infested puppies may require a third deworming.
Worms in the feces
When a dog is dewormed, especially a puppy or relatively young animal, you may spot dead worms in the feces. With puppies, it's not uncommon to see live worms in the stools before they are treated for the infestation, and then dead or live worms excreted in the stool after treatment.
If you see what looks like little rice grains around your dog's anus, he is likely suffering from a tapeworm infestation. You may also see these telltale tapeworm segments in his droppings. Tapeworms live in the dog's small intestine, attaching themselves to the intestinal wall with their hook-like mouths. Dogs pick up tapeworms from fleas, which have eaten tapeworm larva, according to VCA Animal Hospital.
Drugs that eradicate tapeworms are given either by injection or by mouth. In either case, the tapeworms dissolve in the intestine, and you shouldn't see them coming out of the dog after treatment. Preventing the return of tapeworms means implementing a good flea-management program for your pet. Your vet will recommend the best flea preventive for your dog, which may include combination heartworm and flea and tick medication.