Nanophyetus salmincola

Adults of the trematode Nanophyetus salmincola live in the small intestine of domestic dogs and free-ranging fish-eating mammals in northwestern North America and eastern Russia.

Neospora caninum

Neospora caninum is a protozoan parasite, closely related and in several respects similar to Toxoplasma gondii, that is a major cause of abortion in cattle around the world and an occasional cause of neurological disease in young calves, dogs and other mammalian hosts.

Notoedres cati

Mites of the burrowing mite genus Notoedres infest domestic cats and free-ranging felids, and rarely domestic dogs and free-ranging canids, around the world.

Oestrus ovis

Oestrus ovis, the sheep nasal bot, can be found in sheep farming areas worldwide, including in Canada.

Ollulanus tricuspis

The trichostrongyle nematode Ollulanus tricuspis infects predominantly cats and wild felids, and occasionally pigs, foxes and dogs, in Europe, North and South America, Australia and the Middle East.

Onchocerca cervicalis

The nematode Onchocerca cervicalis occurs in horses in many regions of the world where suitable midge intermediate hosts (Culicoides species) are also present.

Oslerus (Filaroides) osleri

Adults of the nematode Oslerus (Filaroides) osleri live in nodules beneath the tracheal mucosa of dogs in many parts of the world, including Canada, and in coyotes in North America.

Otobius megnini

The Argasid (soft) tick Otobius megnini, the spinose ear tick, infects cattle, sheep, dogs, horses and occasionally people in and North America, including Canada, as well as South America, India, and South Africa.

Otodectes cynotis

The ear mite Otodectes cynotis infects dogs and cats and several free-ranging carnivores around the world.

Oxyuris equi

The pinworm nematode Oxyuris equi occurs in horses around the world, including Canada.

Parascaris equorum

The ascarid nematode Parascaris equorum occurs in horses around the world, including Canada.

Physaloptera species

Physaloptera spp. are spiruroid stomach nematodes that occur primarily in cats, wild felids and occasionally dogs in North America, including Canada, as well as in South America, China, and Africa.

Rhipicephalus sanguineus: brown dog tick

Rhipicephalus sanguineus, the brown dog tick, is a medium sized (unfed adult females are 4-5 mm long) yellowish-brown to reddish-brown tick with a dark inornate brown scutum.

Sarcocystis neurona

Sarcocystis neurona is an intracellular, apicomplexan protozoan that occurs in horses and other hosts in the Americas.

Sarcocystis species-pigs

Species of the intracellular, apicomplexan protozoan Sarcocystis occur in mammals, reptiles and birds around the world, including in Canada.

Sarcoptes species of animal origin on people

Sarcoptes mites from animals can infest people (especially from dogs, and much less commonly pigs), although such infestations are usually short-lived, resolving spontaneously in a couple of weeks following loss of access to the infested dog.

Setaria species

Nematodes of the genus Setaria infect cattle, sheep, sometimes other domestic animal hosts, and many free-ranging ungulates around the world, including in Canada.

Setaria species — pigs

Nematodes of the genus Setaria infect cattle, sheep, sometimes other domestic animal hosts, and many free-ranging ungulates around the world, including in Canada.

Stephanofilaria stilesi

Nematodes of the genus Stephanofilaria infect cattle in many parts of the world, including Canada.

Stomoxys calcitrans — stable fly

The stable fly Stomoxys calcitrans occurs around the world. The life cycle involves egg laying in faeces or decaying and damp organic material, for example straw bedding.

Strongyloides stercoralis

The nematode Strongyloides stercoralis is primarily a parasite of people, but also occurs in dogs and sometimes cats.

Strongyloides stercoralis in people

Strongyloides stercoralis is zoonotic, and can be transmitted from dogs to people and vice versa. In the human host, the filariform larvae can cause cutaneous larva migrans as they penetrate the skin, very large burdens of migrating larvae can cause significant lung pathology, and the adult female S. stercoralis can be associated with GI symptoms.

Strongyloides westeri

The nematode Strongyloides westeri occurs in horses around the world, including Canada.

Strongylus edentatus

The nematode Strongylus edentatus occurs in horses around the world, including Canada.

Strongylus equinus

The nematode Strongylus equinus occurs in horses around the world, including Canada.

Strongylus vulgaris

The nematode Strongylus vulgaris occurs in horses around the world, including Canada.

Taenia ovis and Cysticercus ovis

Cysticercus ovis, the infective larval stage of Taenia ovis, a cestode parasite of dogs (and perhaps free-ranging carnivores), occurs around the world, including in Canada.

Taenia solium and Cysticercus cellulosae

Taenia solium is a cyclophyllid cestode with adults found in the small intestine of people and the larval stages (Cysticercus cellulosae) found in muscle tissue of pigs.

Taenia species

The cestode genus Taenia includes several species that as adults live in the small intestine of dogs and/or cats and free-ranging carnivores around the world.

Thelazia species

The nematode Thelazia (eye worm) occurs in cattle and rarely sheep and goats around the world, including in Canada.

Tick-borne pathogens

Relative to the United States and many other countries, the burden of tick-borne pathogens that can infect pets and people is thought to be relatively low in Canada.

Toxascaris leonina

Toxascaris leonina is an ascarid nematode of the small intestine of domestic dogs and cats and free-ranging canids and felids.

Toxocara canis

Toxacara canis is an ascarid nematodes of the small intestine of dogs and free-ranging canids. It occurs around the world, including Canada, although in the northern regions of this country it is to some extent replaced by Toxascaris leonina.

Toxocara cati

Toxacara cati is an ascarid nematodes of the small intestine of cats and free-ranging felids. It occurs around the world, including Canada.

Toxocara vitulorum

The small-intestinal nematode Toxocara vitulorum infects cattle, buffalo, zebu and rarely sheep and goats, mostly in tropical and subtropical climates like those in Africa, India and Asia.

Toxoplasma gondii

Toxoplasma gondii is a zoonotic intracellular apicomplexan protozoan parasite of mammals and birds that occurs around the world, including in Canada.

Toxoplasma gondii

Toxoplasma gondii is a zoonotic intracellular apicomplexan protozoan parasite of mammals and birds that occurs around the world, including in Canada.

Toxoplasma gondii — pigs

Toxoplasma gondii is a zoonotic intracellular apicomplexan protozoan parasite of mammals and birds that occurs around the world, including in Canada.

Trichinella species

Historically in Canada, infection of pigs with the zoonotic nematode Trichinella, specifically T. spiralis, was a significant public health concern, but currently the national pig herd is considered free of the parasite except for a possible small focus around Halifax, Nova Scotia.

Trichinella species in people and animals

Trichinella is a genus of zoonotic nematode that occurs in carnivores and omnivores (mammals, including people, reptiles and birds) around the world, including in Canada.

Trichuris vulpis

Adults of the nematode Trichuris vulpis live in the large intestine of dogs and rarely cats. The life cycle is direct and the infective stage is a larvated egg.

Trictrichomonas foetus

Recognition of the Trictrichomonas foetus as an important enteric parasite of cats first occurred in the mid-1990s. Since then reports from several regions of the world have established that the parasite is an important pathogen in these hosts.

Trictrichomonas foetus

Recognition of the Trictrichomonas foetus as an important enteric parasite of cats first occurred in the mid-1990s. Since then reports from several regions of the world have established that the parasite is an important pathogen in these hosts.

Trypanosoma cruzi

Trypanosoma cruzi is a hemoflagellate protozoan parasite primarily found in the southern USA and central and south America.