Roundworms are another common parasite most often found in puppies. The worms are usually heavy-bodied and grow to about 6" in length.

Infection usually occurs as larvae that have lain dormant in an adult female dog are reactivated when female dog becomes pregnant. The larvae begin to migrate through placenta to liver of fetus. They also will migrate to mammary glands of mother, so that puppies can also become infected while nursing.

The time from roundworm larvae infection to adult stage is about 27 days. Most roundworms live about 4 months in puppy and are usually expelled by natural immune system of puppy before 6 months of age.

So, if puppies naturally expel these parasites, how do adult dogs end up with them? The adult dog ingests them by eating some food supply that contain larvae.

Tapeworms

Another very common worm is tapeworm. This worm lives in intestines of both dogs and cats. The worm is transmitted by fleas. When a dog or cat has fleas, they will naturally ingest tapeworm while grooming. The tapeworm then makes its way to intestine.

There are usually no noticeable symptoms for most part, although sometimes your dog may show some stomach upsets, diarrhea or just seems somewhat lethargic. You can often tell if your pet has tapeworms by finding small, whitish worm segments that look like small grains of rice under tail of your pet or on its bedding. Also, you dog may begin "scooting" their rear end along floor because of irritation. It takes approximately three weeks from time your dog ingests flea until you begin to see tapeworm segments.

Although not generally harmful to an animals health, tapeworms are certainly something you'll want to rid your dog of. One of first treatments for tapeworms is to begin a program of flea control treatment program for your pet and immediate environment of your house and yard.