Cross Species - Top 10 Tickborne Diseases Part 2

Question 1

what is the signalment of animals commonly affected by epizootic bovine abortion?

Answer 1

seen in cows, mostly heifers, in the foothills around sacromento/san joaquin valley & eastern sierra nevadas in the western USA

Question 2

what is another name for epizootic bovine abortion?

Answer 2

foothill abortion

Question 3

what is the classic case presentation of foothill abortion?

Answer 3

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

Question 4

what is the etiology of foothill abortion?

Answer 4

agent - pajaroellobacter abortibovis

tick vector - ornithodorus coriaceus (pajarello tick, soft argasid tick)

Question 5

how is foothill abortion diagnosed based off of findings of the aborted fetus?

Answer 5

no signs of autolysis

lymphadenopathy

petechiae

hepatosplenomegaly

multiple organs have granulomatous inflammation

increase in fetal IgG

Question 6

how is foothill abortion prevention?

Answer 6

expose heifers & open cows to the endemic region prior to breeding them

rarely cows will abort more than once

Question 7

what is the only way in which a naive cow will be affected by foothill abortion?

Answer 7

they must be exposed to the bacteria during the first 6 months of pregnancy for abortion to occur

Question 8

why was p. abortibovis difficult to isolate?

Answer 8

the bacteria likely only divides once per day & is from a family of bacteria that don’t usually cause mammalian disease

Question 9

what is the common signalment of animal affected by hepatozoonosis?

Answer 9

outdoor dogs in areas where coyotes roam around

Question 10

what is the classic history, season, and case presentation of canine hepatozoonosis?

Answer 10

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

Question 11

what is the etiology of canine hepatozoonosis?

Answer 11

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

Question 12

what is seen on labwork in dogs with hepatozoonosis?

Answer 12

cbc - marked leukocytosis with mature neutrophilia, mild non-regenerative anemia, & may see gametocytes in buffy coat cells

chemistry - hypoalbuminemia, hyperglobulinemia, elevated ALP, & decreased BUN

Question 13

how is hepatozoonosis diagnosed?

Answer 13

radiographs - periosteal proliferation due to muscle inflammation

PCR

pathognomonic onion skin protozoal cysts are often found in muscle biopsies!

Question 14

how is canine hepatozoonosis treated?

Answer 14

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

Question 15

how is hepatozoonosis prevented?

Answer 15

tick control & prevent the dog from eating dead animals with ticks (deer, rabbits, cotton rats)

Question 16

what is the prognosis for hepatozoonosis for the following: untreated, acute treatment alone, & combination therapy followed by decoquinate?

Answer 16

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

Question 17

where is h. americanum endemic?

Answer 17

around the gulf coast but seen as far north as oklahoma

Question 18

what signalment of dogs is predisposed to rocky mountain spotted fever?

Answer 18

dogs under 2 years at a higher risk

pure bred dogs - especially german shepherds

Question 19

what is the classic case presentation of rocky mountain spotted fever?

Answer 19

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

Question 20

what is the etiology of rocky mountain spotted fever?

Answer 20

agent - rickettsia rickettsii

tick vectors - mainly dermacentor variabilis (american dog tick) & d. andersoni (rocky mountain wood tick)

Question 21

what is seen on labwork (cbc, chem, UA, arthrocentesis, & CSF tap) in a dog with rocky mountain spotted fever?

Answer 21

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

Question 22

how is rocky mountain spotted fever diagnosed?

Answer 22

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

Question 23

how is rocky mountain spotted fever treated?

Answer 23

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

Question 24

what are poor prognostic factors of rocky mountain spotted fever?

Answer 24

guarded prognosis - renal disease, neurologic signs, vasculitis, or coagulopathy

Question 25

what is the prognosis of rocky mountain spotted fever?

Answer 25

excellent with early recognition & prompt treatment - may develop lifelong immunity

Question 26

what is the classic signalment of animals affected by tick paralysis?

Answer 26

dogs, sheep, & cattle mostly in the summer usually 5-10 days after tick attachment

Question 27

what is the classic case presentation of tick paralysis?

Answer 27

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

Question 28

what is the etiology of tick paralysis?

Answer 28

salivary neurotoxin secreted by engorged female dermacentor species ticks

Question 29

how is tick paralysis treated?

Answer 29

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

Question 30

what causes tick paralysis in australia?

Answer 30

caused by ixodes holocyclus - much more severe with cranial neuropathies, autonomic dysfunction (hypertension, dilated pupils), & respiratory paralysis

Question 31

what is the prognosis of tick paralysis?

Answer 31

generally excellent with tick removal

can be fatal if undiagnosed & untreated

Question 32

what is the classic signalment of animal affected by tularemia?

Answer 32

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

Question 33

what is the classic case presentation of sheep with tularemia?

Answer 33

ewes - late term abortion

lambs - fever, listlessness, lymphadenopathy, & diarrhea

Question 34

what is the classic case presentation of cats with tularemia?

Answer 34

acute & severe - lethargy, anorexia, weight loss, fever, lymphadenopathy (especially submandibular lymph nodes), mouth/tongue ulcerations, hepatosplenomegaly, icterus, & +/- pneumonia

Question 35

what is the classic case presentation of dogs with tularemia?

Answer 35

usually mild disease

anorexia, lethargy, weakness, fever, mucoid oculonasal discharge, & lymphadenopathy

Question 36

what is the etiology of tularemia?

Answer 36

agent - franciscella tularensis (gram negative coccobacillus)

reservoir hosts & true vectors - dermacentor spp. ticks & amblyomma ticks

common mechanical vectors - deer flies (chrysops discalis)

Question 37

what is seen on labwork in an animal with tularemia?

Answer 37

cbc - panleukopenia or leukocytosis, toxic neutrophils, & thrombocytopenia

chemistry - +/- elevated liver enzymes

Question 38

how is tularemia diagnosed?

Answer 38

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

Question 39

what is seen on necropsy of an animal with tularemia?

Answer 39

miliary white necrotic foci in liver +/- spleen

Question 40

how is tularemia treated?

Answer 40

aminoglycoside - gentamycin or streptomycin

Question 41

how is tularemia prevented?

Answer 41

tick control

avoid wild animal contact

protect animal feed from wild animals

prevent dogs & cats from hunting wild animals

Question 42

what is the prognosis of tularemia in lambs, cats, & dogs with tularemia?

Answer 42

lambs - up to 15% mortality in untreated lambs

cats - rapidly fatal if left untreated

dogs - usually mild & self-limiting

Question 43

why is tularemia a zoonotic concern?

Answer 43

zoonotic & highly infectious via bites, scratches, fomites, ingestion of contaminated meat/water, & aerosolized bacteria!!!

Question 44

what category pathogen is tularemia?

Answer 44

CDC category A pathogen

Question 45

T/F: the infectious dose of tularemia is extremely low

Answer 45

true

Question 46

T/F: tularemia is a reportable disease in some states

Answer 46

true