Equine Top 15 Neurologic Diseases - Part 3 Flashcards
what is the classic case presentation of rabies in a horse?
sudden behavior changes, agitation, aggression, progressive paralysis, rapid breathing, +/- rolling
what is the etiology of rabies?
lyssavirus in family rhabdoviridae
how is rabies diagnosed?
fresh brain tissue from medulla oblongata or cerebellum is sent to a designated lab - immunofluorescent microscopy diagnoses 98-100% of cases
how is rabies treated? how is rabies prevented?
no treatment, always fatal - vaccination to prevent
what are common vectors of rabies?
cats, dogs, skunks, raccoons, foxes, & bats
what is the classic case of neuroborreliosis in a horse?
ataxia, uveitis, cranial nerve deficits, lethargy, poor tongue tone, muzzle tremors, spinal pain, inappetance/weight loss, spooking, muscle atrophy, & occasionally, lameness, peripheral neuropathy, seizures, & arrhythmias
what is the etiology of neuroborreliosis?
borrelia burgdorferi sensu stricto
how is neuroborreliosis diagnosed?
CSF to serum ratio using lyme multiplex (detects 3 different antibodies), serology with C6 ELISA test most often used - serology alone isn’t diagnostic because it can indicate infection or exposure
what is the major reservoir host of b. burgdorferi?
white footed mouse (p. leucopus)
what is the prognosis of neuroborreliosis?
poor even with aggressive therapy
what is the life cycle of b. burgdorferi?
vector of ixodes ticks, white tail deer are the tick host, & reservoir hosts are small mammals (white footed mouse), birds, & reptiles
T/F: many horses in the mid-atlantic region have been exposed to b. burgdorferi & most don’t show clinical signs
TRUE
how is neuroborreliosis treated?
doxycycline or minocycline
what are the diseases included in the alphavirus encephalomyelitidies?
EEE/WEE/VEE
what is the classic case presentation of EEE & WEE?
fever, depression, altered mentation, head droop, dysphagia, paresis/paralysis, lateral recumbency with paddling, +/- pruritus
what is the incubation period of EEE/WEE?
5-14 days
what is the classic case presentation of VEE?
may be asymptomatic/mild, similar neuro signs to EEE/WEE, tachycardia, diarrhea, colic, & sudden death
what is the etiology of alphavirus encephalomyelitidies?
arboviruses - arthropod borne viruses in the togaviridae family
what are the reservoir hosts of EEE? what kind of hosts are horses? what is the vector?
passerines (perching songbirds) +/- rodents, horses are dead end hosts, & culiseta melanura mosquito is the vector
what are the reservoir hosts of WEE? what kind of hosts are horses? what is the vector?
passerines (perching songbirds), +/- black tail jack rabbits, horses are dead end hosts, & culex tarsalis mosquito is the primary vector
what are the reservoir hosts of VEE? what kind of hosts are horses? what are the main vectors?
wild rodents, horses are important amplifiers for epidemic VEE, & many species of mosquitos, black flies, mites, & ticks are vectors
how are EEE/WEE/VEE diagnosed?
serology for IgM antibody capture for EEE/WEE (4 fold elevation in plaque reduction neutralization or high titer in unvaccinated horse), virus isolation only in early febrile stage for antemortem diagnosis, brain tissue for EEE, pancreatic tissue for VEE, IHC or PCR for EEE, lymphopenia often seen with EEE, & azotemia from decreased water consumption is common
what is seen on CSF fluid of a horse with EEE?
neutrophilic or mononuclear pleocytosis