Sarcoptic Mange

1. Sarcoptic Mange • Sarcoptes scabiei mite • ~1/64 of an inch long • Pearly white and oval-shaped • Spines on bodies • Year-round; winter • Humans ("scabies"), canids, felids, bears, mustelids • Common in red fox, wolves, and coyotes in N. America • impacts on younger animals • Highly contagious, direct transfer of mites at any stage of their development • Indirect transfer of mites (mechanical transfer) – importance?

2. Sarcoptic Mange • Highly specific to host type, • Life cycle completed in burrows within epidermis of host • Adult mites mate in small pockets near the surface of skin • Hatched larvae pass through a nymphal stage and continue migration through epidermis, becoming adults within 2 weeks

3. Sarcoptic Mange • Female mites burrow into skin of host; use jaws and front legs to cut skin • Female lays 2-3 eggs each day, up to 2 months • Larvae hatch, 3-4 days • Crawl onto surface of skin, use hair as shelter • Both larvae and adults eat skin cells from hosts

4. Sarcoptic Mange • Oily skin, crusting, hair loss, scab formation • Lesions - physical damage to skin, irritation caused by parasite excretions, and allergic response of host • Hair loss in characteristic patterns (alopecia) • Poor body condition, listlessness, abnormal behavior, increased scavenging • May ultimately die from complications with mange infection or exposure; winter

5. Sarcoptic Mange • Trichodectes canis • Dog biting louse • 2ndary infection

6. Sarcoptic Mange – WI Wolves • 1st identified in a Great Lakes wolf, 1991 • Since 1991, signs of mange detected in 27% of wolves • High of 58% in 1992-1993 • 1993 = 11% decline in wolf population • Some literature suggesting population impact most severe in 2nd or 3rd year of epidemic • Impacts on annual pup survival?

7. Ticks • Ixodes (e.g., deer tick; Lyme disease (Borrelia burgdorferi) • Dermacentor (Am. Dog tick & Rocky Mtn wood tick); Rocky Mountain spotted fever (Rickettsia rickettsii ) • Amblyomma (e.g., lone star tick; Ehrlichiosis (Ehrlichia)

8. Ticks Winter tick (Dermacentor albipictus)

9. Ticks

10. Ticks Winter tick (Dermacentor albipictus)

11. Ticks • Moose begin grooming in Jan (nymph stage) – mechanical and/or immunological irritation • Extensive grooming through Mar-Apr = destroy winter coat • Severe hair loss = gray coloration (undercoat) = "ghost moose".

12. Nasal Leeches • Leech (Genus Theromyzon) feeds directly on blood from nasal passages, trachea and mucous membranes of eyes • Spring/summer - leeches actively seeking potential hosts and reproducing • Dabbling ducks (e.g., mallard, teal, wigeon, northern shoveler, etc.) and swans

13. Nasal Leeches • Protruding from nares or attached externally • Resemble small sacks of blood • Birds vigorously shaking heads, scratching bills or sneezing • Nasal and respiratory tract infestations = labored breathing and gaping (similar to aspergillosis infection)

14. Nematodes = roundworms Complete digestive systems Most species dioecious 2 main categories eggs are infective larva are infective

15. Gizzard Worm • Parasitic nematode • Genus Amidostomum or Epomidiostomum • 10-35 mm, coiled, thread-like roundworm • Beneath surface lining and grinding pads of gizzard • waterfowl

16. Gizzard Worm

17. Gizzard Worm • 1st exposure on breeding grounds • Large worm burdens; reduce vigor, couple with migration, etc… • No field signs • Poor growth/weight gain in young birds? • Emaciation, general weakness • Poor digestion

18. Raccoon roundworm - Baylisascaris procyonis

19. Raccoon roundworm - Baylisascaris procyonis Life cycle is direct or indirect depending on age of raccoon Definitive host

20. Raccoon roundworm - Baylisascaris procyonis Adults in intestines lay eggs

21. Raccoon roundworm - Baylisascaris procyonis Eggs are shed with feces

22. Raccoon roundworm - Baylisascaris procyonis Eggs are shed with feces – loads of ‘em

23. Raccoon roundworm - Baylisascaris procyonis Sticky, proteinaceous outer coat

24. Raccoon roundworm - Baylisascaris procyonis Over 2-4 weeks the eggs develop larvae

25. Raccoon roundworm - Baylisascaris procyonis Can remain infectious for years

26. Raccoon roundworm - Baylisascaris procyonis Embryonated egg with larvae is ingested by young raccoon -- Direct

27. Raccoon roundworm - Baylisascaris procyonis Egg hatches in to larva

28. Raccoon roundworm - Baylisascaris procyonis Larvae in intestines develop into egg-laying adults Infection rates in raccoons are high – as high as 70% of adults and over 90% of juveniles

29. Raccoon roundworm - Baylisascaris procyonis Embryonated egg with larvae are ingested by intermediate hosts

30. Raccoon roundworm - Baylisascaris procyonis Eggs hatch and release larvae into intestines  gut wall  migrate thru the various tissue (larval migrans) causing considerable damage and then encyst

31. Raccoon roundworm - Baylisascaris procyonis In the eye  blindness

32. Raccoon roundworm - Baylisascaris procyonis 5-7% CNS disease

33. Raccoon roundworm - Baylisascaris procyonis Dead intermediate is scavenged by adult raccoon – Indirect

34. Raccoon roundworm - Baylisascaris procyonis Raccoons are ubiquitous in U.S. and urban adapted http://www.maniacworld.com/raccoon-encounter-with-dog-and-cat.html

35. Raccoon roundworm - Baylisascaris procyonis Definitive host??

36. An emerging zoonotic especially of young children • Contact with raccoon feces • Pica/geophagia • Young age (less than 4) • Male • Developmental delay • At any age – anyone exposed to raccoon feces – researchers, wildlife rehabilitators, etc – asymptomatic or subclinical, sometimes ocular migrans or encephalitis

37. Pathology • Aggressive migration of larvae • Molt and grow as migrate • Only 5-7% enter neural (or ocular) tissue – induce an inflammatory (eosinophilic) response  encephalitis • Migrate extensively in brain before being walled off by host • Post-inflammatory atrophy, necrosis, and impairment Very distinctive prominent alae excretory columns multinucleate

38. Encephalitis in an 11-month-old boy. • Abnormal high signal throughout most of the central white matter (arrows) compared with the dark signal expected at this age (broken arrows). • Extensive evidence of raccoon activity and fecal contamination, including 21 latrine sites, were identified on the patient’s property and the adjacent vacant lot. • 11 raccoon were necropsied, all were positive.

39. Raccoon Roundworm • Single adult female worm = 115,000 to 877,000 eggs per day • raccoon infected with multiple worms = shed up to 45,000,000 eggs daily

40. Raccoon Roundworm midwestern U.S. documented in 68–82% of raccoons; >90% juveniles

41. Raccoon Roundworm • Prevalence, intensity of infection, avg # of larvae significantly higher in the highly fragmented landscape • Probability of infection, intensity of infection, and avg # of larvae per mouse per patch varied as functions of forest patch area and isolation (DD)

42. Raccoon Roundworm • A study conducted in Northern California tried to determine if a pattern existed to the preferred location of latrines. While latrines on the ground and on roofs appeared to be the most favorable, preferences varied by location.

43. Raccoon Roundworm • Percentage of Californiaproperties that contained at least one raccoon latrine positive for Baylisascaris procyonis eggs (number of properties = 164).

44. Raccoon Roundworm • Eggs ~ 65 microns in size • Household disinfectants (bleach) will not kill (remove coating) • Fire/heat, boiling water, required to kill eggs

45. Raccoon Roundworm: Trophic-level Effects • Former range of the Allegheny woodrat (inside bold line), and regions where woodrats have disappeared in recent decades (stippled areas).

46. Raccoon Roundworm: Trophic-level Effects • Range of raccoon roundworm in Allegheny woodrat states