Presentation on theme: "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,"— Presentation transcript:
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?
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
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
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
Sarcoptic Mange Trichodectes canis Dog biting louse 2 nd ary infection
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 2 nd or 3 rd year of epidemic Impacts on annual pup survival?
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".
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
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)
Nematodes = roundworms Complete digestive systems Most species dioecious 2 main categories eggs are infective larva are infective
Gizzard Worm Parasitic nematode Genus Amidostomum or Epomidiostomum 10-35 mm, coiled, thread-like roundworm Beneath surface lining and grinding pads of gizzard waterfowl
1 st 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
Raccoon roundworm - Baylisascaris procyonis
Definitive host Life cycle is direct or indirect depending on age of raccoon
Raccoon roundworm - Baylisascaris procyonis Dead intermediate is scavenged by adult raccoon – Indirect
Raccoons are ubiquitous in U.S. and urban adapted http://www.maniacworld.com/raccoon-encounter-with-dog-and-cat.html Raccoon roundworm - Baylisascaris procyonis
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
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
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.
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
Raccoon Roundworm midwestern U.S. documented in 68–82% of raccoons; >90% juveniles
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)
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.
Raccoon Roundworm Percentage of California properties that contained at least one raccoon latrine positive for Baylisascaris procyonis eggs (number of properties = 164).
Raccoon Roundworm -Eggs ~ 65 microns in size -Household disinfectants (bleach) will not kill (remove coating) -Fire/heat, boiling water, required to kill eggs
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).
Raccoon Roundworm: Trophic-level Effects Range of raccoon roundworm in Allegheny woodrat states