Dogs and worms can have an uncomfortably close relationship. Dogs can be great hosts. Unfortunately, they are not great hosts for picnics or parties. They are great hosts for a number of species of worms.

The worms that are most likely to infect your dog are: tapeworms, roundworms, hookworms, heartworms and whipworms.

There are several reasons why dogs are such great hosts to intestinal parasites. First, they are omnivores and will eat just about anything. Second, they are scavengers -- constantly sniffing around looking for something they can eat. And, finally, many dogs routinely clean themselves by licking.

Worms And A Dog's Diet

It is easy for dogs to become worm infested because of their eating habits. For example, dogs can become whipworm infected when they eat worm-infested feces or if they step in feces and then lick their paws. Dogs can also become hookworm infested when they lick themselves and swallow hookworm larvae.

Roundworms can enter the dog when it consumes prey such as a rodent that is carrying developing worms, or when it consumes worm eggs from the soil -- as it feasts on some other dog delicacy.

Puppies are particularly susceptible to roundworms because they can be infected during embryonic development if the mother dog is infected. They can even become infected through their mother's milk

Another intestinal parasite is the tapeworm. These worms, unlike roundworms, whipworms or hookworms, infect the dog when it consumes a flea. Dogs, of course, are walking flea hosts.

Finally, a dog becomes heartworm infected when bitten by a mosquito has fed on another dog that is heartworm infected.

Dogs And Worm Infections

A dog's intestinal tract becomes a great host for parasites once the eggs or larvae enter the dog.

For example, in the case of roundworms, the dog picks up what is called a “second stage larva” from the dirt or some other animal. The egg hatches in the dog's intestinal track and the young worms burrow their way out to encycst in the dog’s other body tissues.

These second stage larvae can remain encysted for years. They will mostly encycst in the dog's liver. Eventually they will migrate to the dog’s lungs where they develop into third stage larvae. Next, they burrow into the small airways and travel to the dog's throat. The dog will then cough up the worms and swallow them, allowing the roundworms to enter the intestinal tract for the second time in their development.

Contaminated Soil And Hookworms

On the other hand, the adult hookworm infects the dog several ways. It can penetrate the dog’s skin directly through the feet or belly or whatever part of the skin is touching the ground. As an alternative, it can enter the dog in soil that is licked and swallowed as the dog cleans itself.

The adult hookworm lives in the dog’s small intestine where it hangs onto the intestinal wall using its six sharp teeth. Many of the worms simply stay and mature into adult hookworms. Other hookworms will break out of the intestine and migrate to the dog’s lung tissue. Here, they develop into 4th stage larvae and, when they are ready, break out of the lung, climb up the dog’s windpipe, get coughed into the throat and swallowed. Once back in the dog’s intestine, these worms complete their maturation to adulthood. Hookworms are dangerous to your dog because once they fasten on to your dog’s intestinal wall, they begin sucking its blood. They are especially dangerous to puppies as a hookworm infection can cause a puppy to bleed out and die.

The adult worm lives and mates within the intestine and, ultimately, the female worm produces eggs. These eggs are released into the dog’s intestinal contents and passed on into the world mixed in its stool.

Contaminated Water And Whipworms

Dogs generally become infected with whipworms by ingesting food or water that has been contaminated with whipworm eggs. These eggs hatch, and, in less than three months, mature into adults in the dog’s intestine where they burrow their mouths into the intestinal wall and feed on blood. The adult worms lay eggs that are passed in the feces. These eggs must remain in the soil for about a month to mature and become capable of causing infection in another dog.

Fleas And Tapeworms

If your dog licks itself and, in doing so, consumes a tapeworm-infected flea, it will eventually have a tapeworm. This is because when the flea is digested, a tiny tapeworm is released into the dog’s system. The worm begins as a head, a throat and a segment. However, it soon begins to grow more segments, each of which has both a digestive and reproductive system.

A tapeworm can eventually grow become six to nine inches long. However, a more typical length is three to four inches.

At some point, the worm will begin shedding segments. When these segments dry out, they look like tiny grains of rice or sesame seeds that you may see in the dog’s stool.

You can usually tell your dog is tapeworm-infected by seeing the worms in the dog’s stool or around its rear end.

Mosquitoes And Heartworms

Heartworms are probably the most dangerous parasite that can infect your dog.

This is because from the time your dog is bitten by a heartworm-carrying mosquito until the time it shows symptoms can be as long as nine months. And by the time it does become symptomatic, the heartworms will already be in your dog’s heart and lungs.

Dogs get heartworms when bitten by a mosquito that has fed on another heartworm-infected dog. When these mosquitoes bite the dog, they leave infected worm larvae on the dog’s skin. As these larvae grow bigger, they leave the tissue and enter the dog’s blood stream through the wall of a small vein. They then travel through the dog’s blood stream and eventually lodge in the chambers on the right side of the dog’s heart where they develop into mature heartworms. It is these mature worms that can clog your dog’s lungs and heart and, if left unchecked, cause your dog’s death.

Dogs And Worms

As you can see, dogs and worms go together like a horse and carriage. In fact, dogs are perfect hosts for intestinal parasites. Their habit of cleaning themselves plus the fact they will eat almost anything and are prone to both fleas and mosquitoes, makes them perfect targets for a variety of intestinal pests.

Next >> What Causes Dog Worms?