Whipworms

Capillaria Trichuris vulpis

WHIPWORM

• The name comes from the thin whip-like protrusions at the end of the adult body. The worms attach to the large intestine and cecum by threading their “whip” through the intestinal lining.

• Very rare in cats.

TYPES

• Trichuris vulpis

MODES OF TRANSMISSION

• Direct – ingestion of eggs

Whipworm Lifecycle

1. Eggs are eaten by host

2. Larvae hatch and begin development in the intestines

3. Larvae mature to adults in the cecum or large intestine

4. Eggs are passed in feces5. Eggs develop

infective larvae

Trichuris vulpis

CLINICAL SIGNS

Signs are usually mild, but include:-Diarrhea-Emaciation-Dehydration-Anemia-Blood in stool

Death may occur in severe cases

Protozoa

IsosporaGiardia trophGiardia cyst

PROTOZOA

• There are several different species of protozoa that are commonly known as coccidian. An infection of protozoa is called coccidiosis. Coccidia infest the walls of the intestines.

TYPES

• Isospera – dog & cat• Sarcocystis – dog & cat• Toxoplasma gondii – cat

MODES OF TRANSMISSION

• Direct – ingestion of eggs• Indirect – ingestion of infected animals

Protozoa Lifecycle

1. Eggs are ingested by direct or indirect routes

2. Parasite’s cell wall is digested and it enters epithelial cells of the intestines where it matures

3. During maturation, the eggs divide and develop into male and female

4. The fertilized female (oocyst) ruptures out of the epithelial cell and is passed in the feces

Giardia

CLINICAL SIGNS

• Diarrhea in puppies and kittens

ZOONOSIS

• Some species will cause disease in humans1. Toxoplasma gondii – causes abortion2. Giardia – ‘Beaver Fever’ is transmitted in contaminated food and water

HEARTWORM

• Can affect dogs, cats and even humans; although in humans the parasite is eliminated in the lungs. Adult heartworms live in the right side of the heart and in the pulmonary artery. The worms are free living, meaning they do not attach to the host’s body.

MODE OF TRANSMISSION

• The organism that causes heartworm is Dirofilaria immitis

• Mosquitoes are the vector• Heartworm is most prevalent in the

southern states with warmer climates (the larvae need warm temperatures to mature) and greater numbers of mosquitoes.

EFFECTS

1. Damage to pulmonary artery lining2. Compromised blood flow3. Fluid leaks from the lungs

LIFE SPAN

• Dog – adults live about 5 years• Cat – adults live only 1-3 years

Heartworm Lifecycle

1. Mosquito bites infected animal picking up D. immitis

2. Mosquito passes D. immitis to the next animal it bites

3. Microfilaria (larvae) migrate to right side of heart – 3 months

4. Microfilaria mature in the heart – 3 months

5. After 6 months, adult worms begin producing microfilaria that are released into bloodstream.

Dirofilaria immitis

CLINICAL SIGNS

• Deep cough• Exercise intolerance• Irregular heart beat

Note: dogs with a light infection may be asymptomatic (without symptoms)

DIAGNOSIS

• There are several methods for diagnosing heartworms. These methods will be successful unless the disease has progressed at least 6 months since no adults are present at that time

METHODS

1. Blood smear to look for microfilaria2. Antigen test - tests for antigens produced

by adult females; there are many commercial tests available

3. X-ray – look for enlarged heart and pulmonary artery

TREATMENT• Often dangerous. There is the possibility

that the dog won’t survive treatment, or that adult worms will form a clot in the arteries. Surgery can be done to remove adult worms. There are 2 non-surgical methods that are often used in combination. One is using an arsenic compound to kill adults. The problem with arsenic is that it could also kill the dog. The second method is to use ivermectin to kill microfilaria.