Top Topics Exotics - Top 6 Cervid Diseases Flashcards
what animals are affected by chronic wasting disease?
white tailed deer, mule deer, elk, & moose - due to the long incubation period, affected animals are over 16 months of age
what is the classic case presentation of chronic wasting disease in cervids?
weight loss, behavior changes, neurologic signs, pu/pd, & aspiration pneumonia is common
what is the etiology of CWD?
misfolded prion protein
how is CWD diagnosed? what test is used for screening?
immunohistochemistry is preferred, ELISA used for screening, or western blot at USDA certified labs (retropharyngeal lymph node especially in white tail deer & mule deer & obex)
what is done for surveillance of CWD?
surveillance: heads provided by hunters & biopsies are done on tonsils, retropharyngeal lymph nodes, & recto-anal mucosa-associated lymphoid tissue
how is CWD controlled?
no treatment - control includes voluntary national CWD herd certification program either by state or herd owner with fencing requirements, individual animal identification, & testing on all animals that die after 12 months of age & surface disinfection with 50% bleach for 30-60 minutes or 1 M sodium hydroxide for 60 minutes
how is carcass disposal done for animals with CWD?
incineration or alkaline digestion
what was the first case of CWD seen in?
mule deer from northern colorado in 1967
how does CWD go through horizontal transmission?
ingestion of urine or feces on forage
T/F: CWD is a reportable disease
TRUE
what is the meningeal worm that affects cervids?
paralestrongylus tenuis
what animals are usually asymptomatic when affected with meningeal worms?
white tail deer
what are aberrant cervid hosts that show clinical signs from meningeal worms?
moose, mule deer, elk, or caribou
what clinical signs are seen with meningeal worm infections in cervids?
lumbar weakness, ataxia, circling, abnormal head positions, paralysis, slow movement, & less wary of humans, - may also have cortical blindness or may see a temporary remission
how are meningeal worms in cervids diagnosed?
CSF analysis, a pleocytosis that may be eosinophilic, elevated protein, & maybe xanthochromia
what is seen on necropsy from a cervid with meningeal worms?
threadlike adult worm in subdural space in white tailed deer but are in the CNS parenchyma of aberrant hosts
how are meningeal worms treated in cervids?
fenbendazole or ivermectin
what is the life cycle of the meningeal worm?
adults lay eggs in white tail deer dura mater which hatch into L1 and are carried to lungs, larvae migrate up bronchial tree and swallowed, larvae exit the deer in mucus coating of feces, snails/slugs feed on the mucus fecal coating & become intermediate hosts where L2 & L3 develop, & white tail deer or aberrant host ingests intermediate hosts or their slime secretions as they graze
what are the main hemorrhagic diseases of cervids? what is important to remember about them? what cervid is most severely affected?
bluetongue & epizootic hemorrhagic disease - clinically indistinguishable from each other
what are the main clinical signs associated with bluetongue & epizootic hemorrhagic disease in cervids?
white tail deer most severely affected - loss of fear of humans, hypersalivation, anorexia, marked head/neck edema, bloody diarrhea, fever, tachycardia, erosions/ulcerations of oral cavity, & death within 36 hours or may follow a chronic course
why are deer dead from epizootic hemorrhage often found in water?
they make an attempt to lower their body temp
what are signs of chronic hemorrhagic disease in cervids?
emaciation, crawling on knees/chest due to sloughing of hoof wall
what is the etiology of hemorrhagic diseases in cervids?
bluetongue: bluetongue virus & epizootic hemorrhagic disease: closely related to orbivirus EHDV
how are hemorrhagic diseases of cervids diagnosed?
viral identification on blood, spleen, lymph nodes, lungs (immunofluorescence, sandwich ELISAS, RT-PCR) & serology: paired serum samples 10-14 days apart (ELISAS, AGID but can’t distinguish EHDV from bluetongue)
how are hemorrhagic diseases of cervids prevented?
avoid swampy areas where biting midges are common, insecticides/repellant, stabling from dusk to dawn, & custom vaccines are now available for deer for bluetongue & EHDV but little info on efficacy
what is the common insect vector of hemorrhagic diseases of cervids?
biting midge - culicoides spp
T/F: there is no evidence of zoonotic potential of hemorrhagic diseases of cervids
TRUE
what is the classic case presentation of tuberculosis in cervids?
abscessed lymph nodes (medial retropharyngeal lymph node), lymphadenopathy, emaciation, & respiratory distress
what is the etiology of tuberculosis in cervids?
usually mycobacterium bovis
how is tuberculosis in cervids diagnosed?
cervidTB stat-pak & cervid dual path platform are serologic tests that together have higehr specificity than the skin test & require only a single handling event
where are lesions from tuberculosis often seen in cervids?
lung abscesses mostly in the dorsocaudal half of the caudal lung lobes
T/F: tuberculosis of cervids is zoonotic
TRUE
T/F: deer typically get abscesses with tuberculosis instead of granulomas like most other species
TRUE
how is tuberculosis in cervids controlled?
test & slaughter or test & segregate
what is the classic case presentation of brucellosis in moose?
usually asymptomatic, abortion in 2nd half of gestation, & retained placenta
what is the classic case presentation of brucellosis in elk?
usually asymptomatic, 2nd half of gestation abortion, retained placenta, hygromas, or bursitis
what is the classic case presentation of brucellosis in caribou/reindeer?
chronic bone/joint infections especially in the carpus
what is the etiology of brucellosis in cervids?
b. suis, b. abortus, & b. melitensis
how is brucellosis of cervids diagnosed?
plate agglutination test
how is brucellosis of cervids treated?
abx may be used but not practical
how is brucellosis of cervids prevented?
test & slaughter - vaccination with strain RB51 plus strain 82 & negative brucella test within 30 days before interstate transport
T/F: wildlife are more likely to contract brucellosis from domesticated animals rather than vice versa
TRUE
T/F: in the USA, brucellosis is more common in elk/moose than deer
TRUE
how do horses usually present with brucellosis?
fistulous withers
T/F: brucellosis is zoonotic
TRUE
what cervids are most often affected by malignant catarrhal fever?
white tailed deer, mule deer, & elk
T/F: there is almost 100% mortality associated with malignant catarrhal fever of cervids with death usually occurring within 48 hours of the start of clinical signs
TRUE
what are the common clinical signs seen with malignant catarrhal fever of cervids?
depression, weakness, hemorhhagic diarrhea, hematuria, sloughing og hoof walls, visual impairment from corneal opacity, alopecia with crusting/hyperkeratosis/ulceration, neurologic signs, & sudden death
what is the etiology of malignant catarrhal fever of cervids?
ovine herpes virus 2 & gammaherpes virus of unknown origin closely related to both the alcelaphine herpes virus-1 of wildbeasts & OHV-2 of sheep
how is malignant catarrhal fever of cervids diagnosed?
ELISA or immunoblotting (may not pick up antibodies in the acute phase)
how is malignant catarrhal fever of cervids treated? how is it prevented?
no treatment - do not farm deer or elk near sheep, sheep pastures, or lamb feedlots & be cautious of fomite transmission
T/F: OHV-2 is endemic in most sheep
TRUE
T/F: AHV-1 & OHV-2 are non-pathogenic to wildebeasts & sheep respectively
TRUE
