Friday, March 30, 2012


Another of the common intestinal parasites are whipworms. These are slightly different from hookworms and roundworms in that they live in the large intestines (particularly the cecum) versus the small intestine. Like the other worms, pets pick up eggs in the environment which travel to the stomach, through the small intestine, and into the large intestine. It can take a long time from ingestion of the egg to maturation of the adult worm (75 days) when it can lay eggs of its own. After eggs are passed into the environment in the feces it takes 2-4 weeks for them to become infective, so early pick up of the feces can help prevent reinfection in affected animals.

The adult worms imbed deep into the intestine wall, so with heavy infestations you can see some major problems including chronic diarrhea, blood in the stool, weight loss, and on occasion a syndrome that mimics Addison's disease. That is why annual stool checks for parasites are important.

If whipworms are found, then your pet should be dewormed. Not all dewormers treat whipworms, so it is important to treat with the right kind of dewormer (typically Panacur). Because the whipworm take so long to mature and the dewormers typically only kill the adult worm and not larval stages, deworming multiple times at 3 weeks and 3 months is recommended. It is also recommended to continue on a heartworm prevention that also prevents whipworms (Interceptor) as the eggs persist in the environement for years and reinfection is always possible.

The one good point about whipworms is that they are not readily transmitted to humans, so you do not have to worry about picking up these parasites yourself. Coming up next are tapeworms.

Friday, March 23, 2012


Hookworms are another of the common intestinal parasites that we see in small animals. The life cycle of hookworms is similar to that of roundworms with a few differences. Like the roundworm, hookworms live in the small intestine. They have sharp teeth that attach to and penetrate the intestinal wall where they are able to live off of the blood of their host. While in the intestine the adult worm lays eggs which are then passed out into the environment in the feces. Once in the outside environment, the eggs hatch and larva emerge. It is the larva that is infective to the dog or cat. The larva can enter the host in a couple of different ways: 1.) by being ingested while the pet is sniffing around outside 2.) penetrating the paw pads or skin of the host.

Once inside the the intestines, the larva can grow into an adult worm and complete the life cycle. Other larva may take an additional step of migrating out of the intestines and making their way to the lungs. They are then coughed up and swallowed to complete the life cycle in the intestines.

Just like roundworms, hookworms can also be passed on to unborn puppies and kittens in the placenta. During stressful events like pregnancy, larva that are dormant in the body can awaken and then spread to the puppies in the placenta. They are also passed in the mother's milk, so if puppies are not infected in the placenta they can be infected soon thereafter while nursing.

If left untreated (especially in the young animals) and the infection is heavy enough, infections can lead to malnutrition, anemia, and possibly death. The good news is that the parasite is readily treatable with common anti-parasite medications like Strongid (pyrantel) or fenbendazole. We recommend that all puppies be dewormed at least 3 times spread out every 2 weeks starting around the time they are 4 weeks old.

Similar to roundworms, hookworms can also be transferred to humans (either through ingestion of contaminated soil or penetration of the feet by larva). This can lead to a condition called cutaneous larva migrans where the larva migrate under the skin in infected people. This is why it is important to not only deworm puppies, but to also check an annual poop sample of your pet to make sure they are clear of parasites.

The next parasite up is whipworms. Stay tuned for more information.

Monday, March 12, 2012


Roundworms are one of the most common parasites that we see in dogs and cats. As their name implies, the adult worms are long and round. They live in the intestines (and occasionally) the stomach of pets. It is not uncommon to see worms in the feces of puppies and, if the infection is large enough you, can see animals vomit up the worms.

Roundworms can be transmitted in a number of different ways. In adults, the worms can actually encyst in a few areas of the body and during stressful events (such as pregnancy) can be shed and spread. The worms can be passed to puppies in the uterus as well as in the mother's milk. In addition, animals can pick up eggs outside by coming in contact with infected soil or poop or by eating animals that are carrying a life cycle stage (like a mouse or other rodent).

After being ingested the eggs hatch in the stomach and then larvae migrate to the lungs. The larvae are then coughed up and swallowed where they make it back to the intestines. Here they grow into adult worms. The adults then lay eggs which are passed out in the feces. These eggs can stay viable in the environment for months to years, so infections can be more common than you think. In puppies we typically see some vomiting or diarrhea when they are infected with roundworms. Adults, however, are usually symptom free, which is why we ask that you bring a stool sample in yearly to evaluate for any parasite infections.

The good news is that the parasites are typically very easily treatable. A medication called Strongid (pyrantel) is the most common dewormer that is used to treat roundworm infections. Since puppies have a very high likelihood of exposure through their mother, we do recommend that all puppies be dewormed with Strongid. The first deworming is done around 2 weeks of age and then repeated every 2 weeks for 3-4 treatments. A poop sample is then checked to make sure that the puppy is parasite free.

Although as a veterinarian I am concerned about your pet, another part of my job is to make sure owners are aware of dangers posed to humans. It is uncommon, but roundworms can be transferred to people (typically through inadvertent ingestion of dirt or with curious toddlers eating dirt). Since the human is not the typical host for the worm, these worms tend to migrate throughout the body of a person and can end up in weird places like the eye and the brain. When here they can obviously cause some unwanted problems. Because of this we like to know your pet's parasite status and if positive treat them for the disease to not only keep them healthy, but also keep you at a lower risk of exposure.

In the next few days I will discuss another of the common parasites, Hookworms. Stay tuned.

Thursday, March 1, 2012

The Scoop on Poop!

In a normal social environment most people try to steer clear of talking about bowel movements. In the veterinary profession though, we talk about it on a daily basis. There is good reason for this; in particular, intestinal parasites.

Most of us do not go around eating dirt or sniffing around outside, but unfortunately many of our pets do. This leaves them at a particular risk for picking up a number of different organisms. The main worry that we have is your pet being exposed to an intestinal parasite. The parasites that we see most commonly are roundworms, hookworms, whipworms, and tapeworms. These are particularly common in puppies or kittens, where they are passed from mother to puppy or kitten.

I have heard a number of people ask why they need to bring in a sample of their pet's poop. They don't see any worms or their pet isn't having digestive issues, so don't think their pet has a problem. While in some instances you can see actual worms come out when your pet is going to the bathroom, in most cases a pet is not showing any problems but is still harboring organisms in their intestines. This is why we ask that you bring in a poop sample every year, as many times your pet can look healthy, but still have a hidden problem with parasites.

The reason why it is important that we know whether your pet has worms is that over the long term these parasites can cause nutritional deficiencies and sickness, can be passed on to other pets, and more importantly can be spread to humans in the environment. When you bring a poop sample in, we perform a fecal floatation test. This test uses a liquid with a particular specific gravity that separates any parasite eggs from the poop. We then look at the sample microscopically to identify a particular parasite.

After we identify if there is a parasite problem, we can then determine the best treatment for the condition.

Over the course of the month, I will blog about specific intestinal parasites and what clinical signs you may notice in your pet and how we can go about preventing these problems or treating the problem if it is present.