Small Ani. Medicine- Tick bourne Dzs 2

drraythe's version from 2016-04-29 14:14

Lyme borreliosis

Question Answer
causative agent of lyme?borrelia burgdorferi (Spirochete bact)
how can you visulalize the spirochetes?visable with dark-field or phase microscopy
vector for lyme?ixodes ticks
which breed of dog is predisposed to the chronic form of lyme?Golden Retrievers
can cats get lyme?has not been described in cats
do all infected animals develop clinical signs?NO
6 main clinical signs of lyme?Acute polyarthritis*, Lameness, Fever, Anorexia, Regional lymphadenopathy, Glomerulonephritis if chronic
can you use synovial fluid to dx lyme? what would you see?commonly when in ACUTE phase, yes. You will see Non-degenerate neutrophils in multiple joints
what is the problem with using IFA and ELISA to dz lyme?Vaccinated dogs remain seropositive for years
how can you distinguish an infected animal from a vaccinated animal?Western immunoblot (Not widely available)
what is the snap test looking for?C6 Peptide Assay
what are the 3 abx you could use to tx lyme? what would the regimen for each be?(1) Doxycycline PO q12 for 30 days (2) Amoxicillin/clavulanic acid q8-12h (didn't say for how long....should I assuem 30d?) (3) Azithromycin PO q24 for 30 days
With treatment, In acute cases clinical improvement should be seen within...24-48 hours
If you begin to treat a chronic lyme problem, what might initially start happening?Worsening polyarthritis, glomerulonephritis, and cardiac abnormalities
how does the lyme vx affect the dz?doesnt prevent dz at all- might just lessen some of the acute dz symptoms
will every animal that gets acute lyme get chronic form?no


Question Answer
what causes Cytauxzoonosis?Cytauxzoon felis
what is the vector for cytaux?tick vector Dermacentor variabilisand possibly Amblyomma americanum.
natural intermediate host for cytaux?bobcat
when (seasonally) do most cytaux dx happen?More than 90% of the cases are diagnosed between April and September
which type of cat is most likely to get cytaux? (life style)indoor/outdoor cats
if I say cytaux, you say...dead cat
cell tropism of cytaux?RBC
3 ways to dx cytaux?blood smear, histopath, PCR
what does cytaux look like on a bleed smear?
why do you see areas of ischemia/thrombosis with cytaux?Obstruction of small vessels with schizont-laden macrophages, results in ischemia and thrombosis
clinical signs of cytaux related to the blood?Pancytopenia, regenerative anemia. Obstruction of small vessels with schizont-laden macrophages, results in ischemia and thrombosis
how do cats appear when in end stages of the dz?Cats often are dyspnic, moribund, hypothermic and neurologic in the end stages of disease
how long until death after beginning of clinical signs? (prog?)Commonly die within 5-7 day after clinical signs begin –poor/grave prognosis
3 drug treatment regimens to use to tx cytaux?(1) Heparin SQ q8 hours (2) Imidocarb dipropionate IM once every two weeks…………..OR……….. (3) Atovaquone (PO q24) and azithromycin (PO q8) combination therapy for 10 days with aggressive supportive care

rocky mountain spotted fever

Question Answer
causative agent of RMSF? what kind of agent is it?Rickettsia rickettsii, a gram-negative obligate intracellular parasite
when (time of year) is RMSF prevalent, and why?Seasonal (April to September) correlating with the tick Dermacentor and Rhipicephalus species life cycle (same as cytaux!)
where do the rickettsia go when they infect the animal, and what do they do? what does this result in?Replicates in endothelial cells of capillaries after 2-14 day incubation--> Causes extravasation of fluid & blood into extravascular space
which tick(s) is the vector for RMSF in the EASTERN usa?American dog tick (Dermacentor variabilis) is involved with transmission of RMSF in the eastern United States.
which tick(s) is the vector for RMSF in the WESTERN usa?The wood tick (Dermacentor andersoni) and Rhipicephalus are involved with transmission of RMSF in the western United States.
what are the two presentations of RMSF (chronic/acute/etc...)subclinical(then I wrote "subacute" above it, not sure if slide is wrong) or ACUTE-- she said THIS IS AN ACUTE DZ!!!! like a million times (so if dog had it for 7mo...prolly not RMSF)
clinical signs of RMSF that have to do with blood/vasculature/lymph etc? OTHER CS?Petechia and ecchymosis, Scleral injection (red sclera), Retinal hemorrhage, Lymphadenopathy, DIC, anemia (remember, replicates in endothelial cells--> vessel probs), also Anterior uveitis, Mucopurulent oculonasal discharge, Neurologic signs, and Polyarthritis
what might the CBC of a dog infected with RMSF look like?Leukopenia followed by leukocytosis, Thrombocytopenia (lots of bleeding=losing platelets fast) anemia (bleeding), CAN lead to DIC
explain how to interpret a paired serum sample for RMSF (which Ig's when etc)A high IgG titer (>1024) is suggestive of exposure within the last tick season.. A positive IgM~ titer (>8) indicates a more recent exposure to the organism
which might indicate a RECENT exposure to RMSF- IgG or IgM?IgM
which drug (and how) do you tx RMSF? is there any reason you might make the regimen diff?Doxycycline- q12h for 21 days. IF LESS THAN 6mo OLD: Enrofloxacin, Tetracycline, Chloramphenicol can be used
is RMSF fatal?can be fatal if untreated, Prognosis good with treatment (<5% die)
can Abs help with RMSF?yes, Protective Antibodies likely


Question Answer
causative agent of bartonella?Bartonella vinsonii subsp berkhoffii and B.henselae (**both are zoonotic but human drs dont know this)
vector for bartonella?Fleas & ticks involved in transmittion (Probably Rhipicephalus)
tell tropism for bartonella?Invade erythrocytes and endothelial cells
bartonella causes what dz in ppl? how does it present?cat scratch dz. In immunocompetant people, you will see huge lymphnodes. In immunocompromised, you'll see bacillary angiomatosis
canine bartonellosis is most often caused by which type of bartonella?Bartonella vinsonii subsp berkhoffii (other sp possible, commonly coinfected)
7 main clinical signs of canine bartonellosis?Endocarditis, Granulomatous lymphadenitis, Granulomatous rhinitis, Heptatitis, Intermittent lameness, CNS signs, Fever
what is a rare type of hepatitis that HUMANS might get from bartonella?Hepatis peliosis
are there chronic infections? how do they affect the dog? is there recurrence?Chronic infections can be well tolerated for years, but can Manifest when stressed, at parturition or if co-infected
how helpful is blood/tissue culture for bartonella?very difficult
can you use PCR for bartonella dx?yes
when might you suspect bartonella on serology?greater than a 1:64 titer
which stain can you use to visualize bartonella? WHEN can you use stain?Visualization with Warthin-Starry silver stain (when acute)
which drugs (and how) to tx bartonella?use Azithromycin PO q24 for 4-6 weeks. If unresponsive, use Rifampin. Can also use Doxy/Fluorquinolone Combo Tx. and Aminoglycosides if not responsive (will need in house ICU w/ frequent renal monitoring)


Question Answer
vector for hepatozoon CANIS? name of dz the canis sp causes?Transmission by *******ingesting brown dog tick (Rhipicephalus sanguineus) --> causes Old World canine hepatozoonosis
vector for hepatozoon AMERICANUM? name of dz the americanum sp causes?Transmission by ********ingesting nymphal or adult Gulf Coast ticks (Amblyomma maculatum)--> causes American canine hepatozoonosis (ACH)
what do WBCs look like with a hepatozoon infxn?can make your WBC go REALLY high- like higher than leukemia
how might the eyes be affected by hepatozoon?OCULAR discharge
where in the US do you find hepatozoon?South East USA
where do the Gamonts of hepatozoon like to live?Gamonts are found in circulating leukocytes of dogs
how might dogs become reinfected with hepatozoon (a way that doesnt involve any ticks or such)Evidence suggests that dogs may become re-infected through the asexual reproduction of the merozoites, which may be associated with the waxing and waning signs.
6 clinical sings of hepatozoon?Fever, weight loss, MM ATROPHY (they can encyst in mm she said), Mucopurulent ocular discharge, Generalized stiff gait and hindlimb paresis (bc stuff in their mms), *Extensive periosteal bone proliferation (NAVLE ?)
what is going on here? *Extensive periosteal bone proliferation seen in hepatozoonosis
which stage in WBCs? which stage in MM?WBCs=gamonts. MM=meronts(merozoites?)
which type of hepatozoon is easier to see on a blood slide?Rarely able to visualize H.americanumgamonts on a stain, Better able to find H.canis
if the blood yields no results, what other tissue can you check for hepatozoon?Skeletal muscle biopsy (biopsy the mm that's hurting them!)
which two tests arent super helpful for hepatozoon?Serology (ELISA) not readily avaliable, there is PCR but its validation is questionable
what is the short (time wise) tx for hepatozoon?Triple therapy for 2 weeks: Trimethoprim-sulfadiazine PO q 12, Clindamycin PO q 8, Pyrimethamine PO q 24....if not improved by end of 2 weeks, do for another 2 weeks.
can you use doxy to tx hepatozoon?nope
remember Trimethoprim-sulfadiazine side effectsKCS, black and tan dogs at higher risk, skin and blood dycriasias
what is the long (time wise) tx for hepatozoon?Decoquinate PO q 12 mixed with food for 2 years (pig coccidiostat)
how common are hepatozoon relapses?common-- asexual repro of meros in mm