Parasites of Dogs and Cats

1. Parasites of Dogs and Cats Part 2: Arthropods and Protozoa

2. Insects • Trichodectes canis (Biting louse) • Linognathus setosus (Sucking louse) • Ctenocephalides (Flea) • Cuterebra (Rodent Bot Fly)

3. Trichodectes canis (Biting louse) • Found as felicola sustratus in the cat • Cause roughened hair coat, itching and dermatitis • May act as intermediate host to Dipylidium caninum

5. Linognathus setosus (Sucking louse of dogs) • Causes skin irritation, itching, dermatitis, alopecia, anemia, roughened hair coat • Usually transmitted by direct contact, but all life stages may be transmitted by fomites • Are species specific

7. Ctenocephalides (Flea) • Infest dogs and cats • Vector for Dipylidium caninum, tularemia, plague, etc. • Die at temperatures below 20 F for 48 hours or at temperatures above 120 for several days • Over 200 species of fleas worldwide • Severe infestations can cause anemia

9. Cuterebra (Rodent Bot Fly) • Infests rodents, companion animals and occasionally humans • Larval stage that infests skin • Acts as an irritant • Migration may be fatal • Have a cutaneous lump with a breathing hole • Use care when extracting as crushing larva may result in anaphylaxis

13. Arachnids • Sarcoptes scabiei (Scabies) • Demodex canis (Demodectic mange) • Otodectes cynotis (Ear mites) • Cheyletiella (Walking dander mite) • Rhipicephalus sanguineus (Brown dog tick) • Dermacentor variabilis (American Dog tick) • Amblyomma americanum (Lone Star tick)

14. Sarcoptes Scabiei (Scabies) • Found as Notoedres cati in cats • Causes intense itching, dry and thickened skin. • Is contagious to humans and other pets • Mites burrow under the skin so may be difficult to diagnose • Diagnose through a skin scraping • Usually have “ventral blowout”

20. Demodex canis (Demodectic Mange) • Rare in cats • Causes areas of alopecia on head, neck, forelimbs. • Can be localized or generalized. • Diagnosed with skin scraping. • Is not contagious • Small numbers considered normal on skin flora • Genetic predisposition

24. Otodectes cynotis (Ear mites) • Intense pruritis of the ear canal. • Can be found on any area of the body • Feed on epidermal debris and are easily transmitted

28. Cheyletiella (Walking Dander mite) • Causes mild alopecia and pruritis • May cause dermatitis in humans • Ingest keratin debris and tissue fluids • Have enormous hook like accessory mouthparts • Are visible to the naked eye

33. Rhipicephalus sanuineus (Brown dog tick) • Vector for canine babesiosis and canine ehrlichiosis • May cause anemia or tick paralysis when found in large numbers

35. Dermacentor Variabilis (American Dog Tick) • Feeds on small mammals but can also feed on dogs and humans • Vector for Rocky Mountain Spotted Fever, tularemia, and can cause tick paralysis in animals and humans

37. Anblyomma americanum (Lone Star tick) • Gets name from white spot on apex of scutum • Feeds on animals and humans • May be vector for Rocky Mountain Spotted Fever and tularemia. • Vector of Ehrlichia

38. Protozoa • Neospora caninum (Neospora) • Isopora (Coccidia) • Giardia canis (Giardia) • Toxoplasma gondii (Toxo) • Sarcocystis (Sarcocystis)

39. Neospora caninum (Neospora) • Transmitted transplacentally or orally • May cause ascending paralysis • A type of coccidia

41. Isopora (Coccidia) • Diarrhea in kittens and puppies. • May be fatal • One of most commonly diagnosed protozan disorders in puppies and kittens. • Rarely a problem in mature animals • Very small in comparison to other parasites

43. Toxoplasma gondii (Toxo) • May cause transient diarrhea in cats • Highly pathogenic to humans, especially fetus in utero

46. Sarcocystis • Not very pathogenic in cats • Very pathogenic in sheep

48. Giardia canis (Giardia) • Causes diarrhea • Occur as cysts or trophozoites in fecal flotation. • May also be tested for through a snap test now available.