Tapeworms - Tapeworms are long, flat worms that attach themselves to your dog’s or cat's intestines. A tapeworm body consists of multiple parts, or segments, each with its own reproductive organs. Tapeworm infections are usually diagnosed by finding segments, which appear as small white worms that may look like grains of rice or seeds on the pet's rear end, in your pet's feces, or where your pet lives and sleeps.
There are several different kinds, or species, of tapeworms that can infect your dog, each with stage(s) in a different intermediate (in-between) host, which the dog eats to become infected. Dipylidium caninum is a tapeworm that uses fleas as its intermediate host, whereas Taenia and Echinococcus species use small rodents (mice, rats, squirrels), rabbits, or large animals (such as deer or sheep) as their intermediate hosts.
Roundworms - Roundworms are the most common of the parasitic worms found inside a dog. Almost all dogs become infected with them at some time in their lives, usually as puppies. Roundworms may be contracted in different ways, making them easy to spread and hard to control.
Your dog may be infected with roundworms from the time it is born because often the mother passes the worms to the puppy while it is still in her body. Roundworms can also develop in a puppy after it is born when the puppy eats larvated eggs from the environment or drinks worm larvae (young worms) in the mother's milk. Another way roundworms are passed is when roundworm larvae are present in the tissues of a mouse or another small mammal and the puppy eats the animal.
Hookworms - Similar to tapeworms and roundworms , hookworms are intestinal parasites that live in the digestive system of your dog or cat . The hookworm attaches to the lining of the intestinal wall and feeds on your pet’s blood. Its eggs are ejected into the digestive tract and passed into the environment through your dog’s feces.
Larvae (young hookworms) that hatch from hookworm eggs live in the soil and can infect your pet simply through contact with and penetration of the skin and through eating the hookworm larvae. It is common for hookworms to infect the host through a pet’s belly or feet as well as to be ingested during routine licking (cleaning).
Whipworms - The whipworm is one of the four most common intestinal parasites of dogs. Whipworms reside in the cecum, which is inside your dog’s body where the small intestine and large intestine meet. Dogs become infected with whipworms by swallowing infective whipworm eggs in soil or other substances that may contain dog feces.
Coccidia - Coccidia are tiny single-celled parasites that live in the wall of your dog or cat's intestine. They are found more often in puppies, but they can also infect older dogs & cats. Pets become infected by swallowing soil that contains coccidia or other substances in the environment that may contain dog feces.
Coccidiosis, the disease caused by coccidia, may not cause any signs in dogs but is usually more serious in puppies. The most common sign of coccidiosis is diarrhea. More severe infections can cause bloody diarrhea. Severe infections, especially in puppies, can kill them. Coccidial infections can be prevented by removing your dog’s feces regularly from your yard or other areas where the dog goes to the bathroom. Because coccidia are found most often in puppies, it is important to have puppies examined for the parasite as soon as possible. Your veterinarian can perform a fecal test to diagnose coccidiosis. If your dog is infected with coccidia, your veterinarian is able to give it effective medications.
Giardia - Giardia is a single-celled parasite that lives in your dog’s intestine. It infects older dogs but more frequently infects puppies. Dogs become infected when they swallow Giardia that may be present in water or other substances that have been soiled with feces. Many dogs infected with Giardia do not get any disease. Giardiasis, the disease caused by Giardia infection, usually results in diarrhea. Having giardiasis a long time can cause weight loss; generally poor condition; and even death, when the disease is serious.
The best way to prevent Giardia infection is to make sure that your dog has safe, clean drinking water. It is important not to allow dogs to drink water from areas where other animals have left their feces. To prevent spreading Giardia (and other parasites), pick up the feces left by your dog immediately and place it in the trash. Be sure to avoid contact with the feces by using gloves, a bag over your hand, or a scooping device.
Heartworm - Heartworms are common in dogs (although cats can get it too) throughout the United States. They are among the most damaging parasites in dogs, though they have been 100 percent preventable for decades. Heartworms are transmitted by mosquitoes and, once mature, take residence in the heart and large vessels of the lungs. The adult female heartworm can measure from 9 to 16 inches in length. The males are a little more than half as long and are easily identified by your veterinarian because of their corkscrew-like appearance.
Heartworm infection can affect many different organs of the dog - heart, lungs, kidneys, and liver, for example - so symptoms may be varied. A veterinarian may suspect that an animal has been infected if an active animal tires easily or shows shortness of breath or coughing; however, one or more tests conducted by your veterinarian may be necessary to determine whether or not your dog has heartworms. The heartworm larvae deposited by the feeding mosquito eventually migrate to the chambers of the heart or into the vessels of the lungs. Once in the heart, the worms can affect blood flow throughout the body.