Meningeal Worm• Moose, elk, caribou, reindeer,

mule deer, black-tailed deer, mule deer/white-tailed deer hybrids, fallow deer, red deer, red deer/elk hybrids, domestic sheep and goats, llamas, guinea pigs, and several bovid and cervid species in zoos

• Appears reindeer, caribou, llamas, and domestic goats are very susceptible

• Speculated that caribou and reindeer may be more likely to acquire infected gastropods because of their feeding habits

• Causes incoordination, circling, recumbency, paralysis

 

Meningeal Worm

• thousands of eggs per gram of deer feces • larvae are highly resistant to environmental forces • weather dependent (wet and cool) – support high gastropod

abundance  

Meningeal Worm

• Distribution of meningeal worm in eastern and western South Dakota. Note separation of eastern from western South Dakota by the Missouri River.

(Christopher and Jenks 2004. Journal of Wildlife Diseases, 40:133-136)

Raccoon Roundworm

midwestern U.S. documented in 68–82% of raccoons

Raccoon Roundworm

- Prevalence, intensity of infection, avg # of larvae significantly higher in the highly fragmented landscape. Within the agricultural landscape- Probability of infection, intensity of infection, and avg # of larvae per mouse per patch as functions of forest patch area and isolation

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

• Former range of the Allegheny woodrat (inside bold line), and regions where woodrats have disappeared in recent decades (stippled areas).

Raccoon Roundworm

• Range of raccoon roundworm in Allegheny woodrat states

Sarcoptic Mange• Sarcoptes scabiei mite• Throughout year, but most

commonly observed during winter months when hair loss can be life threatening

• Infections found in humans (called "scabies"), wild and domestic dogs and cats, bears and mustelids

• Common in red fox, wolves, and coyotes in North America

• Predominantly impacts younger animals.

• Highly contagious, direct transfer of mites at any stage of their development

• Indirect transfer of mites (mechanical transfer) – importance?

Sarcoptic Mange

• ~1/64 of an inch long

• Pearly white and oval-shaped

• Spines on bodies

Sarcoptic Mange• Populations of S. scabiei

usually highly specific to host type, e.g., canid-adapted types specific and spread rapidly among canids

• Life cycle of mite completed in burrows within epidermis of host

• Adult mites mate in small pockets near the surface of the skin

• Hatched larvae pass through a nymphal stage and continue migration through the epidermis, becoming adults within 2 weeks

Sarcoptic Mange• Mites use small suckers on their

legs to hold onto their hosts• Female mites burrow into the skin

of the host using jaws and front legs to cut the skin

• Inside the burrow, the female will lay eggs. She lays 2 or 3 eggs each day, for up to 2 months.

• Mite larvae hatch from the eggs in 3 or 4 days

• Immediately crawl out of the burrow onto the surface of the skin, remain there using host hair as shelter.

• Both larvae and adult mites eat skin cells from their hosts

Sarcoptic Mange• Oily skin, crusting, hair loss, and scab

formation • Typically begin on elbows and towards

the tips of the ears and can eventually involve large areas of the body

• Lesions result from physical damage to the skin, irritation caused by parasite excretions, and the allergic response of the host

• Hair is often lost in characteristic patterns (alopecia)

• Poor body condition and listlessness may be observed in severely infected animals, exhibit abnormal behavior

• Severely affected carnivores may scavenge with increased frequency

• Severely affected carnivores may ultimately die from complications with mange infection or exposure to the elements that results from hair loss in winter

Sarcoptic Mange

• Trichodectes canis• Dog biting louse • 2ndary infection

Sarcoptic Mange – WI Wolves• Sarcoptic mange 1st identified in a

Great Lakes wolf in 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

• Also other disease testing, e.g., Lyme Disease tested positive in 48% of 69 wolf serum samples

• Impacts on annual pup survival?

Lyme Disease

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)

Ticks

Winter tick (Dermacentor albipictus)

Ticks

Winter tick (Dermacentor albipictus)

Ticks

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".

Ticks

Mean number of grooming episodes per hour performed by female moose during the four stages in the life cycle of the winter tick.

Gizzard Worm

• Parasitic nematode• Genus Amidostomum

or Epomidiostomum• 10-35 mm, can be

coiled, thread-like roundworm

• Beneath surface lining and grinding pads of gizzard

• waterfowl

Gizzard Worm

Gizzard Worm

• Ingest larvae• 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

Gizzard Worm

Nasal Leeches• Common on birds north of the

30th parallel and in western North America

• Leech (Genus Theromyzon) feeds directly on blood from the nasal passages, trachea and mucous membranes of eyes

• Peak infestations during spring and summer when leeches actively seeking potential hosts and reproducing

• Winter slows the metabolic rate and activity of leeches

• Many aquatic birds are affected; commonly dabbling ducks (e.g., mallard, teal, wigeon, northern shoveler, etc.) and swans

Nasal Leeches• 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)

Nasal Leeches