There are six main intestinal parasites:
- Whipworms (dogs only)
We will cover different life cycles and stages of the parasites. Your pet can be at risk for intestinal parasites whether they are an outdoor cat or even if you take your dog for a walk or to the dog park. Our pets are exposed to the microscopic eggs when they lick, sniff, or ingest them on the grass or lick them off their paws, for example. Most often you will see the adult parasites in your pet’s stools, but this solely depends on the type of parasite they have and the parasite burden. Most of the parasites are white, but can vary in length (we typically think of the classic “spaghetti”, which very few have this characteristic). The tapeworms can be the same, but the segments look “rice-like”. It is important to also note that tapeworms come from the ingestion of an adult flea or rodent, so flea prevention will also be key.
Some intestinal parasites can be given to humans as well! Many roundworm eggs can accumulate where dogs or cats defecate. People, especially children, who ingest such eggs can develop serious health problems, such as blindness. You can easily become infected if you are cleaning up after your pet and you do not wash your hands properly. Hookworm larvae can penetrate human skin and cause lesions. They can be given to people simply by walking around barefoot in your backyard or garden where the hookworm eggs are. And people can acquire tapeworms through the ingestion of an infected flea. Parasites in humans and pets are transmitted through fecal/oral contact. Remember to wash your hands thoroughly and often if you pet is positive for intestinal parasites.
It is also important to check fecal samples a minimum of once per year, especially in your outdoor cats.
** Important note for cats: We recommend checking at least one fecal sample per year depending on risk of exposure to parasites. Deworming therapy will also depend on levels of exposure. Outdoor cats should ideally be dewormed at least three times per year. They are at high risk of infection and they will need to be treated more often to cover all life stages of each parasite.
Parasites can be very good at hiding. A parasite may try to hide, but they cannot hide from treatment. We recommend deworming therapy even in cases where we don’t see parasite eggs in appropriate cases. This means depending on the life stage they are in, we may not see any parasite eggs, which is what we are looking for under the microscope. You are not always going to see the “spaghetti” like structures (a small worm burden, may be difficult to detect), for example, which is the adult stage (even after deworming). Adult worms are rarely passed unless in heavy worm burdens. We also analyze a sample of a very large sample from your pet, parasites can hide from us too, we might not have hit the “parasite jackpot” today. In this case, prevention or prophylaxis is best.
Intestinal worms can be a serious problem in young puppies and kittens.
Puppies can become infected with roundworms through ingesting the eggs in their mother’s milk. Dogs and puppies can also become infected by sniffing or licking infected feces. Roundworms are most threatening to puppies. The most common consequence of roundworms is growth reduction. Since roundworms eat partially digested food in the intestinal tract, if there is a large burden of roundworms they will rob the growing puppy of vital nutrients. In puppies, clinical signs such as stunted growth, potbelly appearance, and recurrent diarrhea are a good indication of roundworm infection. Adult dogs can have vomiting, diarrhea, or weight loss associated with this parasite. A definitive diagnosis is made by microscopic examination of the dog’s feces. This parasite can be passed onto humans, therefore strict hygiene (handwashing) is important.
If a growing kitten is infected with a large number of roundworms, the worms can stunt the kitten’s growth, cause serious digestive problems, and result in excessive gas formation. Adult cats can have vomiting, diarrhea, or weight loss associated with this parasite. These kittens have a characteristic ‘pot-bellied’ appearance. Kittens can become infected with larvae passing through the milk of their mother. Kittens and adult cats can become infected by ingesting the eggs of other infected kittens or cats. This parasite can be passed onto humans, therefore strict hygiene (handwashing) is important.
Toxocara Canis: 2-4 weeks after infection, adult roundworms release eggs in the small intestine.
Toxocara Leonina: 8-10 weeks after infection, adult roundworms release eggs in the small intestine.
Dogs may become infected with hookworms by one or all of four routes: orally, through the skin, through the mother’s placenta before birth (in utero), and through the mother’s milk. The most significant clinical signs are vomiting, diarrhea, and anemia. Hookworms are diagnosed with a microscopic examination of a stool sample. This parasite can be passed onto humans.
The hookworm attaches to the lining of the small intestines, where it feeds on blood. Evidence of hookworm infection includes anemia, the presence of digested blood in the stool, a poor hair coat, and weight loss. Cats become infected by ingesting the larvae of the hookworm. This parasite can be passed onto humans.
Life Cycle: Eggs are released in feces approximately 10-21 days after infection.
In order to get tapeworms, an intermediate host is needed, in this case, an adult flea. In other words, your dog cannot get tapeworms directly from another cat or a dog. This results in digestive upsets and stunting of growth in puppies. For this parasite, you would need to address the parasite along with treating and preventing fleas to completely resolve the problem.
In order to get tapeworms, an intermediate host is needed, in this case, an adult flea. In other words, your cat cannot get tapeworms directly from another cat or a dog. This results in digestive upsets and stunting of growth in kittens. For this parasite, you would need to address the parasite along with the treating and preventing for fleas to completely resolve the problem.
Dogs and puppies can become infected by sniffing or licking infected feces. Whipworm infection results in watery, bloody diarrhea, weight loss, and general debilitation. The most frustrating aspect of whipworm infections is the high rate of re-infection because the eggs are extremely hardy in the environment. These parasites can last years in the environment!
Lifecycle: Eggs are released in feces 74-90 days after infection.
Coccidiosis is an intestinal tract infection caused by a one-celled protozoan called coccidia. A puppy is not born with coccidia. After birth, puppies are frequently exposed to the mother’s feces. If the mother is shedding the infective cysts in her feces, her puppies can ingest them during nursing. Coccidia generally causes severe diarrhea, vomiting, and dehydration.
Coccidiosis is an intestinal tract infection caused by a one-celled protozoan called coccidia. A kitten is not born with coccidia. After birth, kittens are frequently exposed to the mother’s feces. If the mother is shedding the infective cysts in her feces, her kittens can ingest them during nursing. Coccidia generally causes severe diarrhea, vomiting, and dehydration.
Giardia is an intestinal tract infection caused by a protozoan called Giardia intestinalis. A dog becomes infected with Giardia when it swallows the cyst stage of the parasite. Giardiasis can be transmitted by eating or sniffing the cysts from contaminated ground, or by drinking contaminated water. When Giardia cysts are found in the stool of a healthy adult dog without diarrhea, they are generally considered a transient, insignificant finding. However, in puppies and debilitated adult dogs, they may cause severe, watery diarrhea that requires treatment. Giardia can be passed along to humans.
Giardia is an intestinal tract infection caused by a protozoan called Giardia intestinalis. A cat becomes infected with Giardia when it swallows the cyst stage of the parasite. Giardiasis can be transmitted by eating or sniffing the cysts from contaminated ground, or by drinking contaminated water. The disease is relatively rare in healthy adult cats. The likelihood of developing disease increases when large numbers of cysts are present in the environment from fecal contamination. It is more common in kittens and debilitated adult cats and is a common occurrence in densely populated groups of cats, such as in a cattery, pet store, or animal shelter. Symptoms typically include diarrhea. This parasite can potentially be passed onto humans.
For more information about intestinal parasites please visit:
To see how prevalent each parasite is in your area visit: