Presentation on theme: "Sarcoptic Mange Sarcoptes scabiei mite ~1/64 of an inch long"— Presentation transcript:
1 Sarcoptic Mange Sarcoptes scabiei mite ~1/64 of an inch long Pearly white and oval-shapedSpines on bodiesYear-round; winterHumans ("scabies"), canids, felids, bears, mustelidsCommon in red fox, wolves, and coyotes in N. Americaimpacts on younger animalsHighly contagious, direct transfer of mites at any stage of their developmentIndirect transfer of mites (mechanical transfer) – importance?
2 Sarcoptic Mange Highly specific to host type, Life cycle completed in burrows within epidermis of hostAdult mites mate in small pockets near the surface of skinHatched larvae pass through a nymphal stage and continue migration through epidermis, becoming adults within 2 weeks
3 Sarcoptic MangeFemale mites burrow into skin of host; use jaws and front legs to cut skinFemale lays 2-3 eggs each day, up to 2 monthsLarvae hatch, 3-4 daysCrawl onto surface of skin, use hair as shelterBoth 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 hostHair loss in characteristic patterns (alopecia)Poor body condition, listlessness, abnormal behavior, increased scavengingMay ultimately die from complications with mange infection or exposure; winter
6 Sarcoptic Mange – WI Wolves 1st identified in a Great Lakes wolf, 1991Since 1991, signs of mange detected in 27% of wolvesHigh of 58% in1993 = 11% decline in wolf populationSome literature suggesting population impact most severe in 2nd or 3rd year of epidemicImpacts on annual pup survival?
11 TicksMoose begin grooming in Jan (nymph stage) – mechanical and/or immunological irritationExtensive grooming through Mar-Apr = destroy winter coatSevere hair loss = gray coloration (undercoat) = "ghost moose".
12 Nasal LeechesLeech (Genus Theromyzon) feeds directly on blood from nasal passages, trachea and mucous membranes of eyesSpring/summer - leeches actively seeking potential hosts and reproducingDabbling ducks (e.g., mallard, teal, wigeon, northern shoveler, etc.) and swans
13 Nasal Leeches Protruding from nares or attached externally Resemble small sacks of bloodBirds vigorously shaking heads, scratching bills or sneezingNasal and respiratory tract infestations = labored breathing and gaping (similar to aspergillosis infection)
14 Nematodes = roundworms Complete digestive systemsMost species dioecious2 main categorieseggs are infectivelarva are infective
15 Gizzard Worm Parasitic nematode Genus Amidostomum or Epomidiostomum 10-35 mm, coiled, thread-like roundwormBeneath surface lining and grinding pads of gizzardwaterfowl
17 Gizzard Worm 1st exposure on breeding grounds Large worm burdens; reduce vigor, couple with migration, etc…No field signsPoor growth/weight gain in young birds?Emaciation, general weaknessPoor digestion
36 An emerging zoonotic especially of young children Contact with raccoon fecesPica/geophagiaYoung age (less than 4)MaleDevelopmental delayAt 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 encephalitisMigrate extensively in brain before being walled off by hostPost-inflammatory atrophy, necrosis, and impairmentVery distinctive prominent alaeexcretory columnsmultinucleate
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 RoundwormSingle adult female worm = 115,000 to 877,000 eggs per dayraccoon infected with multiple worms = shed up to 45,000,000 eggs daily
40 Raccoon Roundwormmidwestern U.S. documented in 68–82% of raccoons; >90% juveniles
41 Raccoon RoundwormPrevalence, intensity of infection, avg # of larvae significantly higher in the highly fragmented landscapeProbability 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 RoundwormA 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 RoundwormPercentage of California properties 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