Ticks Flashcards
Ticks on dogs most likely in Ontario
American dog tick (Dermacentor variablilis)
Deer tick (ixodes Scapularis)
Distribution of dermacentor species in USA
D. variabilis mostly East, pockt on west coast
D. andersoni in continental west
> these look the same to the eye
Habitat of D. variabilis? Is it likely to establish indoors and why?
lives in grassy meadows, young forests, along trails
-unlikely to establish indoors as it has many wildlife hosts
season activity of D. variabilis adults
Spring (and summer)
Dermacentor variabilis common name and what it rransmits
american dog tick
-rickestsia rickettsi (RMSF)
-Francisella tularensis
- cytauxzoon felis (only SE USA)
>causes tick paralysis
rarely, if ever, transmits disease in canada
Dermacentor andersoni common name and diseases it transmits
Rocky mountain wood tick
Transmits (rarely in canada)
-rickettsia rickettsii
-francisella tularensis
>causes tick paralysis (rare)
Where in the USA is the highest risk for RMSF and cytauxzoon?
west continent has pocket of RMSF
East has large pocket for cytauxzoon and smaller of RMSF (inside cyto- zone)
ixodes transmits what diseases
-borrelia burdorferi (Lyme)
-Anaplasma phagocytophilum
>causes tick paralysis (rare)
habitat of ixodes scapularis
diciduous forests and adjascent brush or grass
seasonality of ixodes
adults: small peak Oct, large peak in May
nymphs: peak in summer
where are ixodes infected with lyme and how do they get it
Northeast, where they feed on rodents in larval and nymph stages
where are most cases of lyme geographically
NE USA
(in Ontario, along north coast of lake ontario, lake eerie)
Why is the distribution of ixodes scapularis changing?
-bird migration
-changes in deer population
- reforestation
-climate change
proportion of ixodes scapularis infected with borrelia burgdorferi in ontario, in regions
Overall passive surveillance ontario: 18.4%
Kingston: 31.2%
Murphy’s Point park: 79%
Long point, lake eerie: 60%
Possible next endemic tick for canada
amblyomma americanum; the lone star tick
-currently rare in canada
what does the lone star tick transmit
ehrichia ewingii (4Dx+)
cytauxzoon felis (primary vector)
where do we find rhipicephalus sanguineus?
prefers warm, humid climate (rare in canada)
-only tick that can establish in homes/kennels/vet hospitals
R. sanguineus transmits:
-Babesia canis
-Ehrlichia canis (4Dx+)
- Anaplasma platys (4Dx+)
topical tick control options for dogs
-selamectin (revolution)
- permethrin + imidacloprid + pyriproxyfen (K9 Advantix II)
- fluralaner (bravecto)
-fipronil (frontline; only in USA)
how often are tick control meds for dogs given?
-all monthly except bravecto which is 3 months
problem with revolution for dogs in ontario
-not on label dor dermacentor or ixodes (only rhipicephalus and fleas)
>does “aid in control” for d. variablilis
spectrum of canine advantix II
All:
- D. variabilis
- I. scapularis
- R. sanguineus
- A. americanum
- fleas
spectrum of canine bravecto
- D. variabilis
- I. scapularis
- R. sanguineus
- fleas
(no A. americanum)
spectrum of canine frontline
All:
- D. variabilis
- I. scapularis
- R. sanguineus
- A. americanum
- fleas
permethrin issue
bad for cats
topical tick medications for cats
- fluralaner (bravecto)
- fipronil (frontline)
- sarolaner + selamectin (revolution plus)
-esafoxolaner + eprinomectin + praziquantel (nexguard combo)
spectrum of feline bravecto
- D. variabilis
- I. scapularis
-fleas
spectrum of feline fipronil
All:
- D. variabilis
- I. scapularis
- R. sanguineus
- A. americanum
- fleas
> but USA only
spectrum of feline revolution plus
- D. variabilis
- I. scapularis
-fleas
spectrum of feline nexguard combo
-ixodes scapularis
-amblyomma americanum
-fleas
oral tick medications for dogs
-fluralaner (bravecto)
-afoxolaner (nexguard)
-sarolaner (simparica)
-lotilaner (credelio)
spectrum of oral tick control for dogs, all products:
- D. variabilis
- I. scapularis
- R. sanguineus
- A. americanum
- fleas
>for all products EXCEPT:
-no amblymma for bravecto
-no rhipicephalus for nexguard
oral tick control option for cats and spectrum
lotilaner (credelio cat)
-ixodes and fles
medication for tick control collars (USA only) and spectrum
flumethrin (tick drug - resembles permethrin but safe for cats) + imidacloprid (Seresto)
- D. variabilis
- I. scapularis
- R. sanguineus
- A. americanum
- fleas
how long do tick collars have activity for?
8 mo
how long does a tick need to be attached for to transmit lyme?
> =36h before transmission occurs
when does seroconversion occur following lyme infection?
3-5 weeks after infection
how common is clinical lyme disease in dogs that are infected? cats?
-90-95% of dogs never become clinical
-cats essentially 0% clinical
incubation period of lyme in dogs, and signs
-incubation = 2-5 months
-fever, anorexia, polyarthritis
- shifting leg lameness, joint swelling
- lymphadenomegaly
nature of lyme arthritis signs in dogs, and treatment? other less common presentation?
signs of lyme arthritis are transient and respond quickly to oral antibiotics (doxycycline)
- lyme nephritis is less common than lyme arthritis (can kill)
does borrelia cause illness in cats?
-cats can be seropositive, but it is unknown if they can become ill
what does 4Dx look for?
-E. canis (and E. ewingii)
- A. phgocytophylum (and A. platys)
- D. immitis
- Lyme
ACVIM 2018 consensus update on Lyme berreliosis in dogs and cats, on routine screening
Routine screening
-recommended that a qualitative borrelia burgdorferi antibody assay be included with annual wellness exam for healthy dogs living in or near endemic areas in N.A.
-This allows:
>follow up proteinuria screening (2-3x/year) for all seropositive dogs and early intervention for possible Lyme nephritis
>evaluation of risk exposure for owners
-Lyme vaccination does not interfere with this response
ACVIM 2018 consensus update on Lyme berreliosis in dogs and cats, quantitative C6 testing
- the magnitude of quantitative C6 is not predictive of illness
-insufficient published evidence that higher titers predict illness or are associated with future illness to advocate routine use of this test in healthy dogs
-useful for monitoring response to treatment (determine titer on day of treatment and 6 mo later)
ACVIM 2018 consensus update on Lyme berreliosis in dogs and cats, treatment of healthy dogs
-4/6 panelists do not routinely recommend treatment for seropositive dogs that are not clinical and not proteinuric
ACVIM 2018 consensus update on Lyme berreliosis in dogs and cats: prevention - tick control
-all dogs in Borrelia burgdorferi endemic areas (whether vaccinated or not) should receive adequate tick control year-round
NOTE: justification for prevention during winter months in Canada is questionable
ACVIM 2018 consensus update on Lyme berreliosis in dogs and cats: prevention - vaccination
-consensus for vaccination was not reached
-3/6 panelists recommend vaccination, stating:
>healthy (non-clinical, non-proteinuric) Borrelia burgdorferi-
seronegative and –seropositive dogs in endemic regions of
North America may be vaccinated with any of the currently
available vaccines for Borrelia burgdorferi
- it is not reccomended to vaccinate sick or proteinuric dogs
If a healthy (non-clinical) dog tests
positive for Borrelia burgdorferi, how
should it be managed ?
- Monitor for clinical signs for 12 months:
– If clinical signs consistent with Lyme disease > treat with doxycycline - Monitor for proteinuria today and 2-3 times over 12 months:
- Test: urine protein (dipstick)
- If proteinuric > treat with doxycycline
- Test for antibody to B. burgdorferi every 12 months:
– If tests positive, test for proteinuria that day then 2-3 times over next
12 months
– If tests negative, do not test for proteinuria
Options if fully engorged
Ixodes scapularis
- Evaluate dog for clinical signs consistent with Lyme disease and proteinuria for next 6 months (option most consistent with
ACVIM consensus statement) - Carry out B. burgdorferi serology today and 6-8 weeks later
- evidence of seroconversion ?
- negative result more useful than a positive result - Submit tick for PCR evaluation of B. burgdorferi
- negative result more useful than a positive result
If a dog tests positive for other
tick-borne pathogens,
how should it be managed ?
- If clinical signs consistent with pathogen, TREAT -
Anaplasma phagocytophilum disease and symptoms:
(granulocytic anaplasmosis):
- disease incubation = 1-2 weeks:
- fever, anorexia, lethargy
- lameness, stiffness, joint swelling
- lymphadenomegaly, splenomegaly, hepatomegaly
(from ixodes scapularis)
Ehrlichia canis disease and symptoms
(monocytic ehrlichiosis):
- disease incubation = 8-20 days:
- fever, anorexia, weight loss
- polyarthritis
- lymphadenomegaly, splenomegaly
- CNS signs, dermal petechiae/ecchymoses
- cardiac arrythmias, anterior uveitis,
- scleral bleeding
- mucosal petechiae
(from rhipicephalus sanguineus)
Anaplasma platys disease and symptoms
(thrombocytic anaplasmosis):
- disease incubation = 8-15 days?
- mild fever, uveitis
- petechiae, ecchymoses
(from rhipicephalus ehrlichiosis)
Ehrlichia ewingii disease and symptoms:
(granulocytic ehrlichiosis):
from Amblyomma americanum
- disease incubation = 18-28 days:
- fever, anorexia
- stiffness, joint swelling
- CNS signs
if a healthy (non-clinical) dog tests positive for toher tick-borne pathogens, how should it be managed?
If clinical signs consistent with pathogen, or CBC abnormality, treat with:
doxycycline for 1 month
