VTNE Review: Small Animal Intestinal Parasites

how are nematodes diagnosed?

via fecal floatation with zinc centrifugation

nematode

• roundworm

• most common in dogs and cats is Toxocara canis

• causes the zoonotic disease ocular larva migrans

• treated with piperazine, pyrantel, or fenbendazole

• fecal-oral, transplacental infection most common

• live in the small intestine

nematode

• hookworm

• most common species are Ancylostoma caninum and Uncinaria stenocephala

• causes the zoonotic disease cutaneous larva migrans, which occurs via skin penetration

• in percutaneous infection, the larvae migrate through the skin to the lung, where they molt and are swallowed and passed into the small intestine

• treated with fenbendazole, pyrantel

• can cause HGE and severe anemia

• fecal-oral, transmammary (common in puppies), percutaneous infections

nematode

• whipworms

• Trichuris vulgaris

• fecal-oral transmission

• severe infection may lead to hyperkalemia and hyponatremia (pseudo-Addison’s)

• large intestinal parasite

• eggs have bipolar plugs on the ends

• treated with fenbendazole, may be prevented with milbemycin (Interceptor)

cestode

• tapeworm

• Dipylidium caninum is most common in dogs and cats and requires a flea as the intermediate host; flea is usually inadvertently swallowed due to grooming

• Echinococcus granulosus and Taenia spp. are transmitted by ingestion of infective hydatid cysts during perdation of rabbits, rodents, birds, etc

• flat and segmented; the eggs contained within the segments; segments are referred to as proglottids

• proglottid pieces are released from the end of the worm and shed in the feces; resemble a grain of rice

• praziquantel is the treatment of choice

trematode

• fluke

• fasciola hepatica is the most well known and is known as the common liver fluke

• adults can be found in the hepatic bile ducts

• seen most commonly in cattle or sheep that have been grazing in endemic areas

• requires a snail as an intermediate host and the parasite is most common in areas of high rainfall or moist environments

• treated most commonly with albendazole

trematode

• giardia

• life cycle of flagellated protozoan (trophozoites) and infective resistant cysts

• fecal-oral transmission, often through contaminated water sources

• often causes a watery diarrhea

• potentially zoonotic

• treated most often with fenbendazole (Panacur) or metronidazole (Flagyl)

• cysts may be seen on a fecal floatation but Giardia ELISA is the most sensitive test

• the trophozoites may be seen on a direct smear of a fresh fecal sample

• coccidia

• single celled intestinal microscopic parasites

• Isospora is most common in dogs and cats

• Eimeria is most commonly seen in poultry/birds, rabbits

• species specific

• treated with sulfadimethoxine (Albon)

• Eimeria stiedai causes hepatic coccidiosis in lagomorphs (rabbits)

• seen on a fecal float or sometimes a direct smear