(part 2)

By Kaye Wigginton, D.V.M.
published in the Northeast Times

 

Let’s face it, creepy, crawling, jumping, wiggly parasites freak us out! No one wants to see these in or on us or our four-legged family member. Well, not only are these parasites unwelcome, they also transmit diseases to our pet and us. Last month, we discussed fleas and ticks and their diseases. This month, we will discuss the most common intestinal parasites and their diseases. Another, very important and major parasite in dogs and cats, Heartworms, was discussed in a previous article. It is important to remember that all of these parasites can be prevented, treated and/or controlled with proper veterinary care.

 

The four most common worms that your dog or cat can have are Roundworms, Hookworms, Whipworms and Tapeworms. Roundworms and Tapeworms can be seen with the unaided eye, but Hookworms and Whipworms are so small that they are rarely seen in the stool. However, the EGGS can be seen under a microscope after the stool sample has been prepared through a flotation or centrifugation process. When your veterinarian wants to perform a fecal test on your pet’s stool sample, do it! Even if the test reveals no eggs that day, it does not rule out parasites in your pet. Many times it takes several samples from different days to actually see the eggs. This is because of the life cycle of the worm and the timing of when the eggs will be present in the stool, so your veterinarian may ask you to continue testing several times if she or he suspects parasites. Some common protozoan parasites are Coccidia, Giardia and Toxoplasma. These tiny, single celled organisms can only be diagnosed through proper testing. Diagnosis of intestinal parasites is made through physical examination of your pet, clinical signs, age and lifestyle of your pet and laboratory testing. Remember that some pets have no clinical signs of parasites and others are severely ill.

 

Nearly every puppy and kitten is born with Roundworms. This is because the larvae are transmitted from the mother to the puppy or kitten either via the milk or the bloodstream. Dogs and cats are also exposed through other pets’ feces. The female dog can harbor the Roundworms in her tissues and the female cat has the larvae in her mammary glands. A single female Roundworm can shed up to 100,000 eggs per day.   Common signs of Roundworms in puppies and kittens include pot-bellied appearance, abdominal discomfort, depressed appetite, vomiting, and diarrhea, or poor growth. 

 Roundworms can cause serious disease in people. Children are especially susceptible because they have poor hygiene skills and often play in areas where dogs, cats, and raccoons have defecated. As many as 10,000 human cases are reported each year. The disease in people is called Visceral Larval Migrans. The worm egg is ingested, larvae develop and migrate through the person’s intestinal wall and into the body tissues and internal organs. Larvae invading into the eye (Ocular Larval Migrans) or the brain (Cerebral Larval Migrans) are common complications of this disease. 

 

Hookworms are transmitted to puppies and kittens in a similar way as Roundworms (via the mother and through direct exposure from feces). Hookworms can penetrate through the skin or be ingested. Once inside the body, these worms actually attach to the intestines and suck blood. Blood loss can progress to severe anemia. Other signs of this disease include weakness, diarrhea (with or without blood), decreased appetite, and vomiting. The faster this parasite is diagnosed the better for your pet. Hookworms can also cause serious disease in people. These larvae can penetrate through intact skin causing a disease called Cutaneous Larval Migrans. This causes a potentially serious irritation and scarring inflammation of the skin.

 

Whipworms are found more commonly in dogs; however, infection in cats and people are possible. These worms live in the large intestines and cecum (similar to the human appendix). These worms also feed on blood. Your pet can become infected by ingesting the eggs through contaminated food, water or from the soil. The Whipworm eggs are very hardy in the environment; therefore, once they are present it is very difficult to ever eradicate them. They can live in moist soil for years, and are resistant to freezing, but are somewhat susceptible to drying. There is not an effective way to kill the Whipworm eggs in the soil. The only way to eradicate them is to replace the soil with new soil, concrete or gravel. If your dog is diagnosed with Whipworms; after treating for them, your veterinarian may recommend an oral medication to be given life long to control this parasite.

 

Tapeworms rarely cause serious disease in the dog and cat. (There is one type of Tapeworm (Echinococcus spp.) that your pet can get that is transmissible and serious to humans, but it is very rare in most areas of the U.S.) The most common Tapeworm for dogs and cats is Dipylidium caninum and your pet is infected by ingesting a flea or by hunting and eating wildlife or rodents infested with fleas. Humans (mostly children) can be infected also by ingesting a flea. These parasites can be seen in the feces, around the anal area, or dried up and stuck in the hair of your pet or in their bedding. These worms are segmented and flat. The segments, when dried, look like small golden colored grains of rice. These worms, in your pet, can cause debilitation and weight loss and vomiting so they should be treated by your veterinarian when diagnosed. Also, flea control will be recommended, as they are what transmit Tapeworms.

 

Coccidia, Giardia and Toxoplasma are one-celled organisms also known as protozoa.

 Coccidia tend to be opportunistic protozoans; meaning that they are most commonly found in young puppies and kittens less than six months old, in immunosuppressed  adult animals, or in animals who are stressed in other ways (change of environment or ownership, housed with lots of other animals, other disease present, etc.) Unlike some of the worms mentioned above, a puppy or kitten is not born with this parasite. But, once the puppy or kitten is born, if the mother is shedding the infective cysts in her feces, then the young animal will ingest them and coccidia will develop in their intestines. The effects of this parasite can be quite devastating to a young animal. It can lead to severe diarrhea, dehydration, vomiting and death. 

 

Giardia  are commonly found in the intestines of many animals, including humans. A few animals will carry Giardia organisms and not have any clinical signs of disease. Giardia is protected by an outer shell, so it can survive outside the body and in the environment for long periods of time. It is transmitted from animal to animal or human through the ingestion of cysts from contaminated food or water (drinking water or other water sources, such as recreational water like pools, rivers, hot tubs, lakes, etc.) The most common signs for pets and humans include diarrhea, blood or mucous in the feces, gas, nausea and vomiting. This parasite can cause significant disease in a young or stressed animal. 

 

Toxoplasma is also a protozoan parasite found throughout the world. More than 60 million people in the US alone, may be infected with this parasite. Very few of those infected people even have symptoms because a normal, healthy immune system usually keeps Toxoplasma from causing illness. However, pregnant women and immuno-compromised individuals are at risk of serious health problems.  Pregnant women who get infected just before or during early pregnancy (during the first trimester) can pass this parasite on to their unborn child through the placenta. The newborn usually will not have any symptoms of disease at birth, but they may develop very serious eye, brain, or other organ damage later. Cats can get the parasite from eating raw meat, and from eating small animals like rodents and birds or anything that is contaminated with feces from another cat that is shedding the parasite. Strictly indoor cats that are fed commercial and/or well-cooked diets are very unlikely to carry this parasite. Signs of illness in cats include no symptoms, anorexia, fever, difficulty breathing, pneumonia, lethargy, icterus (yellow skin and mucous membranes), anemia, ocular and neurologic disorders. The most common way that people ingest Toxoplasma is by eating raw or under cooked meat especially pork, lamb or venison; gardening without gloves and then putting their hands in their mouth; from unwashed fruits or vegetables that are contaminated or from drinking water contaminated with cat feces. Litter box exposure is the least common way for a human to be infected. Since it usually takes 1-5 days for the feces to be infective, litter boxes cleaned daily have little risk. In order to prevent exposure to this parasite, be sure to eat meat that is well done, wash fruits and vegetables thoroughly, use gloves for gardening, practice good hygiene when cleaning out litter boxes daily,  feed commercial canned and dry cat food to your cat, and keep your indoor cat indoors to prevent exposure. Toxoplasmosis is diagnosed by blood testing.

 

Remember, once your pet has any of these parasites (except Tapeworms), he or she is able to pass them on to others. All puppies and kittens should begin a de-worming program at 2 weeks of age. Even if no parasites are ever diagnosed, they will need to be de-wormed every 2 weeks until they are 12-14 weeks old because as you just read, most puppies and kittens are born with either Roundworms, or Hookworms, or both. Adult dogs and cats should have a fecal exam performed at least annually and anytime your pet is ill. The treatment schedule for parasites is always dependent on the specific parasite and the life cycle of that parasite. Most of these require multiple treatments to completely rid the pet of the parasite. Multiple fecal testing is also required to be sure the parasite is gone. It is not uncommon for puppies and kittens to have more than one type of parasite at the same time. So don’t be surprised if you go home from your first veterinary visit with different medications and different schedules for treatments. There is not just one medication that treats all of these worms and protozoan parasites.

 

 

Please refer to the Center for Disease Control website at www.cdc.gov for more information on these parasites and their diseases.