April - Parasites

April - Parasites

There are six major intestinal parasites in cats and dogs. Most of these parasites can be diagnosed by a fecal float, but a fecal smear may also be necessary to identify giardia and bacterial overgrowth. Please visit our Intestinal Parasite Resource Center for more helpful information on this subject.

HOOKWORMS (Ancylostoma spp): These worms are common in both dogs and cats. Animals can become infected with hookworms by eating infective eggs or larvae; penetration of footpads or skin by larvae; transmission through the milk while nursing; or, transmission from the mother into the fetus while still pregnant. It takes three weeks from the time of infection until eggs are passed into the stool.

Symptoms: weight loss, diarrhea, and bloody, tarry stools. Worms can sometimes be seen in the stool. Infected puppies are commonly pale, weak, and have long-standing deficiencies. They may or may not have diarrhea.

Treatment: Oral deworming medication and correction of any anemia. A follow up treatment is given 3 weeks later. Worms will usually be seen in the stool after oral deworming medication is administered. All fecal material needs to be picked up and disposed of for the next 5-7 days during treatment. Any other pets exposed to hookworms should also be treated. Several heartworm preventives contain added medication to help prevent re-infection with hookworms.

Concern in humans: The hookworm larvae can penetrate human skin and potentially cause a skin problem called cutaneous larval migrans' or creeping eruption.' No one should be barefoot for 5-7 days while the pet is being treated for hookworms. Humans can also become infected by eating improperly washed vegetables, which may harbor contaminated soil.

CDC's Hookworm Fact Sheet

ROUNDWORMS (Toxocara spp): These worms are also commonly seen in dogs and cats. Animals are infected by ingestion of other infected animals (rats), consuming infective worm eggs from soil in the environment (generally through normal grooming), nursing from an infected mother dog, during embryonic development when an infected mother dog is pregnant. Eggs are passed in the stool 3 weeks after infection. Worms can sometimes be vomited up or seen in the feces.

Symptoms: poor hair coat, diarrhea, ill-thrift, pot-bellied appearance, and sometimes secondary bacterial pneumonia

Treatment: Oral deworming medication with a follow up dosage in 3 weeks. All fecal material needs to be picked up and disposed of for the next 5-7 days. Again, the worms will be seen in the stool and they look like spaghetti. Most heartworm preventives contain medication to help prevent re-infection with the worms.

Concern in humans: Roundworm larvae can penetrate human skin. The migrating larvae can affect various organs in the body, causing mechanical damage and also granulomas to form. This disease is called Visceral larval migrans' occurring most commonly in children. They are most commonly infected by inadvertently consuming worm eggs in soil (typically by getting dirty fingers in their mouths). Although the worm is not present in its correct host it tries to complete its life cycle anyway. The worm gets lost in the human body (classically in the eye), dies, and generates an extreme inflammatory reaction. If the worm dies within the human eye, blindness usually results. No one should be barefoot for 5-7 days following treatment.

CDC's Roundworm Fact Sheet

WHIPWORMS (Trichuris sp): This worm is diagnosed in dogs 3 months of age or older. Diagnosis can sometimes be difficult because whipworms are not prolific egg-layers. Infection is via fecal-oral transmission. Eggs do not appear in the feces until 3 months post-infection. There are species of whipworms that can infect cats, but cats are clean animals and fastidious around feces, and they rarely get infected. When they do, worm numbers are so small that symptoms hardly ever occur.

Symptoms: weight loss and diarrhea (+/- blood). Symptoms may also mimic those of Addison's disease. Here, a waxing and waning weakness with inability to conserve salt ultimately creates a dehydration crisis. The syndrome mimics Addison's disease in every way except that testing for Addison's disease will be negative and deworming yields a complete recovery.

Treatment: Oral deworming medication with a follow up treatment in 3 months. One of the monthly heartworm preventives will also prevent re-infection with this parasite.

TAPEWORMS (Dipylidium and Taenia spp): Tapeworms are obtained by eating an infected flea. The tapeworm can also be transmitted by eating infected small mammals.

Symptoms: Tapeworms are normally diagnosed by the visualization of the small, rice-like' worms in the stool (most common method); or seeing the eggs on a fecal flotation exam. A negative fecal flotation exam does not completely rule out the possibility of tapeworm infection. Some clinical signs can be unthriftiness, shaggy coat, irritability, diarrhea, or lethargy.

Treatment: Oral deworming medication or an injection. Control can be achieved by preventing exposure to fleas.

Concern in humans: Problems are rare. People can become infected with tapeworms by the rare occurrence of ingestion of an infected flea.

GIARDIASIS: This is a common protozoan found in all animals. It lives in the small intestine. Infection is via the fecal-oral route. The incubation period is 1-2 weeks.

Symptoms: unapparent, continuous, or persistent with diarrhea and weight loss. Several examinations are sometimes needed to identify the organism.

Treatment: Oral medication to all exposed pets.

Concern in humans: People can become infected with this protozoa by fecal-oral transmission, which includes drinking untreated water (rivers and streams).

COCCIDIOSIS (Isospora and Eimeria spp): Different species of coccidia infect all animals. Transmission is fecal-oral and usually due to unsanitary conditions. It is commonly seen in the young and immune suppressed animals.

Symptoms: weight loss, lethargy, and a mucoid (+/- blood) diarrhea.

Treatment: Oral medication for 10 days. All exposed pets should be treated. Sanitary measures should be taken and raw meat should not be fed.

Concern in humans: While there are species of coccidia that can infect people (Toxoplasma and Cryptosporidium, for example), the Isospora species of dogs and cats are not infective to people.

TO PREVENT INTESTINAL PARASITES:

Have your pets stool tested every 6-12 months, or at any sign of intestinal parasite infestation.
Over-the-counter deworming medications may not always be effective. If you believe your pet has an infestation, call your veterinarian to obtain the proper deworming medication
Remove feces from your lawn, street, or kennel daily.
Exercise your pets in grassy areas not frequented by other animals.
Prevent your pet from eating rodents such as mice, rats, and rabbits.
Prevent your pet from eating earthworms (roundworm infection).
Control fleas!
Deworm female pets before breeding and again after whelping to prevent infection of newborn pets.