Diseases & Prevention

Provided within this website is some general information about the diseases associated with pet feces.

Dog feces is more than just a nuisance - it can pose a serious health hazard. Why? A number of common parasites, including round worm, are transmitted via dog feces. When infected dog droppings are left on the ground, the eggs of the roundworms and other parasites can linger in the soil for years. As a result, anyone who comes in contact with the soil also comes in contact with the infected eggs.

Children run the greatest risk of infection because they're prone to play in the dirt at the park or playground and then put their hands in their mouths or rub their eyes with their hands. But even a group of teens or adults playing Frisbee or touch football in an open area could be in danger. Parasitic infections can make humans extremely sick, and for pregnant women, can pose a serious harm to their unborn child.

What are roundworms?

Roundworms describes a whole bunch of different worm parasites. The most common dog roundworm is Toxocara canis. Humans have a different roundworm, as do cats, horses, pigs, and other animals. Dogs get roundworms either from eating worm eggs off the ground or because the mother dog was infected and passed the worms to her puppies during her pregnancy. Adult roundworms have a funny face, with three big lips surrounding their mouth. They feed on partially digested food in the dogs intestine.

Although the risk to humans is slight, roundworm is a major health concern. Roundworm lives in the small intestine of dogs. It is a microscopic and parasitic organism. Eggs are passed into the environment in the dog's waste. The eggs then take two weeks to a month to become infective.

There is no risk from fresh dog waste. But after becoming infective, eggs can remain in the soil for several years. Humans do not develop adult roundworms, although migration of larvae through tissues and organs can cause disease. Humans usually become infected through contact with eggs in the soil or by accidental ingestion.

Direct contact between infected dogs and humans is not considered to play a role in the transmission of roundworm. Young children are at the greatest risk. They often eat dirt and grass and fill their mouths with contaminated hands. Hand powered wheel chair users and field sports players also face greater risks.

Roundworm is not present in dogs that receive regular worm treatments. Picking up dog waste before roundworm eggs can become infective is equally important.

What causes heartworm disease?

Heartworm disease (dirofilariasis) is a serious and potentially fatal disease in dogs. It is caused by a worm called Dirofilaria immitis.

Heartworms are found in the heart and large adjacent vessels of infected dogs. The female worm is 6 to 14 inches (2.3 to 5.5 cm) long and 1/8 inch (5 mm) wide; the male is about half the size of the female. One dog may have as many as 300 worms.

How do heartworms get into the heart?

Adult heartworms live in the heart and pulmonary arteries of infected dogs. They have been found in other areas of the body, but this is unusual. They survive up to 5 years and, during this time, the female produces millions of young (microfilaria). These microfilaria live in the bloodstream, mainly in the small blood vessels. The immature heartworms cannot complete the entire life cycle in the dog; the mosquito is required for some stages of the heartworm life cycle. The microfilaria are therefore not infective (cannot grow to adulthood) in the dog, although they do cause problems.

As many as 30 species of mosquitoes can transmit heartworms. The female mosquito bites the infected dog and ingests the microfilariae during a blood meal. The microfilariae develop further for 10 to 30 days in the mosquito and then enter the mouth parts of the mosquito. The microfilariae are now called infective larvae because at this stage of development, they will grow to adulthood when they enter a dog. The mosquito bites the dog where the haircoat is thinnest. However, having long hair does not prevent a dog from getting heartworms.

When fully developed, the infective larvae enter the bloodstream and move to the heart and adjacent vessels, where they grow to maturity in 2 to 3 months and start reproducing, thereby completing the full life cycle.

Hookworm infection in Dogs and Cats.

Hookworms have a direct life cycle meaning that they do not necessarily need a host to be transmitted. In pets, hookworm ova(egg) are passed in the host's feces and develop to the first larval stage if the temperature and humidity are adequate. Ova can hatch in 10-12 hours at 30 degrees centigrade and in 9 hours at 37 degrees centigrade. Infection can occur via ingestion or skin penetration (commonly infested thru the feet) followed by a pulmonary migration, a developmental stage in the gastric glands, or an arrested state in the muscular tissue in older animals. Migration and maturation occur in 17 days. Transport hosts, especially rodents, may play a role in the transmission of this parasite.

Young dogs and cats are affected more severely, since they are less able to cope with depleted iron reserves.

Clinical signs may be one or more of the following:

  • Intestinal blood loss causing anemia
  • Bloody diarrhea
  • Weight loss
  • Poor hair coat

Hookworms are diagnosed by fecal flotation (Veterinarian). The ova are unembryonated and must be taken from a fresh specimen since they hatch rapidly in warm weather. Therefore, unless you are going to the veterinarian quickly it is best to refrigerate stool samples or better yet have the vet extract the stool sample at their office. Your pet may not like that idea but it will yield the more accurate result.

There are many de-wormers available over-the-counter but they contain medications that are designed to "flush out" the parasite. But as the name implies, Hookworms hook onto the intestinal wall and "do not come off without a fight". Many pets experience mild to severe distress because of these de-wormers. These de-wormers were used by veterinarians decades ago, but veterinary medicine has come a long way since then.

Today, many anthelmintics are effective against hookworms in both dogs and cats. An aggressive treatment and prevention program as defined by your veterinarian normally entails two initial treatments 2 weeks apart (killing the hatched eggs and before they can hatch again and reproduce administering a second dose), plus an aggressive preventive program. Since the medication can only kill what's in the system monthly checkups for 3-4 months are needed until a pattern of negative tests results are established. Because of the life-cycle of the hookworm, monthly combo preventative can help control but not usually eliminate the problem.

Also, it is extremely important to thoroughly clean and disinfect the affected areas. If this is not feasible walk your pet in a different area and if possible away from where other pets go. ALWAYS, pick up after your pet goes to the bathroom to minimize the chance of reinfection.

The most important aspect of hookworms is that they could pose a health hazard to humans. Especially if you have children, it is imperative to keep on top of the situation and have your pet regularly tested. In humans, hookworms causes cutaneous larval migrans. The parasite can penetrate human skin and cause a linear, tortous, erythematous, and pruritic dermatitis (kids are more susceptible). Therefore, if you own a pet good hygiene, prevention and management of stool area should be #1 on your list.

What are Tapeworms?

The most common tapeworm of dogs (and cats) is called Dipylidium caninum. This parasite attaches to the small intestinal wall by hook-like mouthparts. Adult tapeworms may reach 8 inches (20 cm) in length. The adult worm is actually made up of many small segments about 1/8 inch (3 mm) long. As the tail end of the worm matures, the terminal segments break off and pass into the stool. Occasionally, the mobile segments can be seen crawling near the anus or on the surface of a fresh bowel movement. These segments look like grains of rice and contain tapeworm eggs; the eggs are released into the environment when the segment dries. The dried segments are small (about 1/16", or 2 mm), hard and golden in color. These dried segments can sometimes be seen stuck to the hair around the dog's anus.

A less commonly found tapeworm, called Echinococcus, also occurs in dogs.

How do my dog get tapeworms?

In order for a dog to become infected with the common tapeworm, Dipylidium, the dog must swallow a flea that contains tapeworm eggs. This process begins whentapeworm eggs are swallowed by flea larvae (an immature stage of the flea). Contact between flea larvae and tapeworm eggs is thought to occur most frequently in contaminated bedding or carpet. Next, the dog chews or licks its skin as a flea bites; the flea is then swallowed. As the flea is digested within the dog's intestine, the tapeworm hatches and anchors itself to the intestinal lining.

A dog become infected with Echinococcus when it eats a small mammal, usually a rodent, that contains the worm. Foxes and coyotes (and the wild rodents upon which they prey) are important in the life cycle of this parasite. Dogs and cats may also become infected if they eat rodents carrying the parasite.

What are Whipworms?

Whipworms are intestinal parasites which are about 1/4 inch (6 mm) long. They live in the cecum and colon of dogs where they cause severe irritation to the lining of those organs. This results in watery, bloody diarrhea, weight loss, and general debilitation. They are one of the most pathogenic worms found in dogs.

How did my dog get whipworms?

Whipworms pass microscopic eggs in the stool. The eggs are very resistant to drying and heat, so they can remain viable in the dog's environment for years. They mature and are able to reinfect the dog in 10-60 days. The eggs are swallowed and return to the lower intestinal tract to complete the life cycle.

How is whipworm infection diagnosed?

Whipworms are diagnosed by finding eggs with a microscopic examination of the stool. However, multiple samples are often required because these parasites pass small numbers of eggs on an irregular basis. Any dog with chronic diarrhea can be reasonably suspected to have whipworms, regardless of several negative stool examinations. It is an accepted practice to treat for whipworms based on assumption of infection. Response to treatment is an indication that whipworms were present but could not be detected on fecal examination.

How are whipworms treated?

Where are several drugs that are very effective against whipworms. Two treatments are needed at a 3-4 week interval, but because reinfection is such a problem, it is advisable to treat again every 3-4 months or to put the dog on a heartworm prevention product that contains an ingredient that prevents infection with whipworms. Whipworms are not nearly as common now because of widespread use of the types of heartworm prevention products.

Can I get whipworms from my dog?

No. Whipworms are not infectious to people; they are parasites of the dog.

What is Giardia Disease

Giardia spp. are parasitic protozoans (single celled organisms) found in the intestines of many animals, including dogs. This microscopic parasite clings to the surface of the intestine or floats free in the mucous lining the intestine.

The prevalence of Giardia in dogs of Alberta is not known. However, rates of 5 to 10 per cent have been suggested. This level is consistent with those reported in surveys from the United States and many other countries.

What is the life cycle of Giardia?

Giardia occurs in two forms: a motile feeding stage that lives in the intestine a non-motile cyst stage that passes in the feces.

Encystment occurs as the parasite travels to the large intestine. The cysts are fairly resistant and can survive for several months as long as sufficient moisture is provided. Mature cysts are usually found in the feces of infected animals.

Animals become infected by ingesting cysts. These cysts break open in the intestine to release the motile feeding stage (trophozoite). Giardia increase their numbers by each organism dividing in half repeatedly by a process called binary fission.

What are the different kind of species of Giardia?

Species of Giardia are morphologically similar. It was customary to give each Giardia a different name when it was found in a new host. For example, the Giardia in dogs was called Giardia canis, in cattle, Giardia bovis, and so on. Today, scientists believe that few species occur, and each species can infect more than one host. However, more research is needed on identifying each species and determining the hosts they can infect.