Cross Species - Top 10 Tickborne Diseases Part 2 Flashcards
what is the signalment of animals commonly affected by epizootic bovine abortion?
seen in cows, mostly heifers, in the foothills around sacromento/san joaquin valley & eastern sierra nevadas in the western USA
what is another name for epizootic bovine abortion?
foothill abortion
what is the classic case presentation of foothill abortion?
abortion storms, up to 60%, occurring in the last trimester
cows may give birth to weakened or dead calves
usually occurs in cows shortly after they are moved to the area - cows DO NOT show signs of illness
what is the etiology of foothill abortion?
agent - pajaroellobacter abortibovis
tick vector - ornithodorus coriaceus (pajarello tick, soft argasid tick)
how is foothill abortion diagnosed based off of findings of the aborted fetus?
no signs of autolysis
lymphadenopathy
petechiae
hepatosplenomegaly
multiple organs have granulomatous inflammation
increase in fetal IgG
how is foothill abortion prevention?
expose heifers & open cows to the endemic region prior to breeding them
rarely cows will abort more than once
what is the only way in which a naive cow will be affected by foothill abortion?
they must be exposed to the bacteria during the first 6 months of pregnancy for abortion to occur
why was p. abortibovis difficult to isolate?
the bacteria likely only divides once per day & is from a family of bacteria that don’t usually cause mammalian disease
what is the common signalment of animal affected by hepatozoonosis?
outdoor dogs in areas where coyotes roam around
what is the classic history, season, and case presentation of canine hepatozoonosis?
history - tick exposure or ingestion of wild animal within the past month
season - usually in summer or fall
clinical case - waxing & waning signs including: fever, depression, reluctance to rise/stiff gait, hyperesthesia, muscle wasting, mucopurulent ocular discharge, +/- bloody diarrhea
what is the etiology of canine hepatozoonosis?
etiology - hepatozoon americanum
host - amblyomma maculatum (gulf coast tick)
dog is infected after ingesting ingesting a tick or diseased mammal
cysts most likely in skeletal muscle
what is seen on labwork in dogs with hepatozoonosis?
cbc - marked leukocytosis with mature neutrophilia, mild non-regenerative anemia, & may see gametocytes in buffy coat cells
chemistry - hypoalbuminemia, hyperglobulinemia, elevated ALP, & decreased BUN
how is hepatozoonosis diagnosed?
radiographs - periosteal proliferation due to muscle inflammation
PCR
pathognomonic onion skin protozoal cysts are often found in muscle biopsies!
how is canine hepatozoonosis treated?
acute treatment, for 2 weeks combine:
TMS, clindamycin, & pyrimethamine
followed by chronic treatment, decoquinate for 2 years or until PCR negative
NSAIDS & treat other tick borne diseases if present
how is hepatozoonosis prevented?
tick control & prevent the dog from eating dead animals with ticks (deer, rabbits, cotton rats)
what is the prognosis for hepatozoonosis for the following: untreated, acute treatment alone, & combination therapy followed by decoquinate?
untreated - fatal within months
acute treatment only - fatal within a year even with repeated combination therapy for relapses
combination therapy followed by decoquinate - long-term cure
where is h. americanum endemic?
around the gulf coast but seen as far north as oklahoma
what signalment of dogs is predisposed to rocky mountain spotted fever?
dogs under 2 years at a higher risk
pure bred dogs - especially german shepherds
what is the classic case presentation of rocky mountain spotted fever?
fever, lethargy, stiffness/generalized pain, hemorrhages (mucus membrane petechiae/ecchymoses, epistaxis, hematochezia, hematemesis)
vomiting, diarrhea, cough/dyspnea, head tilt or other neuro signs, peripheral edema, uveitis, chorioretinitis, lymphadenopathy, & splenomegaly
what is the etiology of rocky mountain spotted fever?
agent - rickettsia rickettsii
tick vectors - mainly dermacentor variabilis (american dog tick) & d. andersoni (rocky mountain wood tick)
what is seen on labwork (cbc, chem, UA, arthrocentesis, & CSF tap) in a dog with rocky mountain spotted fever?
cbc - thrombocytopenia, anemia
chemistry - hypoalbuminemia, azotemia, elevated liver enzymes, hyponatremia, hypochloremia, hypokalemia, hypocalcemia
urinalysis - proteinuria
arthrocentesis - elevated neutrophils or monocytes with elevated protein
CSF - neutrophilic or monophilic pleocytosis with elevated protein
how is rocky mountain spotted fever diagnosed?
labwork findings
IFA - 4X increase or single titer > 1:1024 (acute titer often negative)
latex agglutination - 1:32 or higher
direct FA on tissue samples prior to antibiotics
PCR
how is rocky mountain spotted fever treated?
one of the following antibiotics - doxycycline, tetracycline, enrofloxacin, or chloramphenicol
prednisolone - will not exacerbate disease, but will reduce the immune-mediated response
fluids - careful if edema is present
what are poor prognostic factors of rocky mountain spotted fever?
guarded prognosis - renal disease, neurologic signs, vasculitis, or coagulopathy
what is the prognosis of rocky mountain spotted fever?
excellent with early recognition & prompt treatment - may develop lifelong immunity
what is the classic signalment of animals affected by tick paralysis?
dogs, sheep, & cattle mostly in the summer usually 5-10 days after tick attachment
what is the classic case presentation of tick paralysis?
progression over 1-3 days: stiff gait, weakness that is more pronounced in the pelvic limbs, & then flaccid paralysis with absent reflexes (mentation, cranial nerves, & elimination are generally normal)
dogs are usually able to wag their tail despite paralysis
what is the etiology of tick paralysis?
salivary neurotoxin secreted by engorged female dermacentor species ticks
how is tick paralysis treated?
careful removal of engorged female ticks - should result in improvement within 24 hours & recovery by 72 hours
may have to shave long-haired dogs - check ear canals & between toes
acaricide if you strongly suspect it
supportive care
what causes tick paralysis in australia?
caused by ixodes holocyclus - much more severe with cranial neuropathies, autonomic dysfunction (hypertension, dilated pupils), & respiratory paralysis
what is the prognosis of tick paralysis?
generally excellent with tick removal
can be fatal if undiagnosed & untreated
what is the classic signalment of animal affected by tularemia?
wide range of wild animal hosts: domestic sheep, cats, & dogs are the most commonly affected in veterinary medicine
most often in central & western america
animal usually has had recent contact with rabbits
what is the classic case presentation of sheep with tularemia?
ewes - late term abortion
lambs - fever, listlessness, lymphadenopathy, & diarrhea
what is the classic case presentation of cats with tularemia?
acute & severe - lethargy, anorexia, weight loss, fever, lymphadenopathy (especially submandibular lymph nodes), mouth/tongue ulcerations, hepatosplenomegaly, icterus, & +/- pneumonia
what is the classic case presentation of dogs with tularemia?
usually mild disease
anorexia, lethargy, weakness, fever, mucoid oculonasal discharge, & lymphadenopathy
what is the etiology of tularemia?
agent - franciscella tularensis (gram negative coccobacillus)
reservoir hosts & true vectors - dermacentor spp. ticks & amblyomma ticks
common mechanical vectors - deer flies (chrysops discalis)
what is seen on labwork in an animal with tularemia?
cbc - panleukopenia or leukocytosis, toxic neutrophils, & thrombocytopenia
chemistry - +/- elevated liver enzymes
how is tularemia diagnosed?
serology - 4X increase or acute markedly high titer
PCR/IFA/culture of tissue samples are definitive but must be very cautious as it is highly infectious
what is seen on necropsy of an animal with tularemia?
miliary white necrotic foci in liver +/- spleen
how is tularemia treated?
aminoglycoside - gentamycin or streptomycin
how is tularemia prevented?
tick control
avoid wild animal contact
protect animal feed from wild animals
prevent dogs & cats from hunting wild animals
what is the prognosis of tularemia in lambs, cats, & dogs with tularemia?
lambs - up to 15% mortality in untreated lambs
cats - rapidly fatal if left untreated
dogs - usually mild & self-limiting
why is tularemia a zoonotic concern?
zoonotic & highly infectious via bites, scratches, fomites, ingestion of contaminated meat/water, & aerosolized bacteria!!!
what category pathogen is tularemia?
CDC category A pathogen
T/F: the infectious dose of tularemia is extremely low
true
T/F: tularemia is a reportable disease in some states
true
