Common blood parasites in dogs

High time for a quick revision among busy vet practitioners. Hope it is helpful to you.

1. COMMON BLOOD PARASITES
IN DOGS AND CATS
Dr. Abhishek Kalundia
B.V.Sc. & A.H., M.V.Sc., Ph.D. (pursuing)
The Alpha and Omega Pet Hospital
Hyderabad, TelanganaState –10
India

2. List of Blood parasite and their primary hosts
Veterinary Practice
1.Ehrlichiosis& Anaplasmosis(Dogs and Cats)
2.Babesiosis(Dogs)
3.Cytauxzoonosis(Cats)
4.Hemotropicmycoplasma(Dogs and Cats)
5.Hepazoonoses(Dogs)
6.Trypanosomiasis(Dogs)
7.Schistosomiasis(Cattle)
8.Theileriases(Cattle)

3. Anaplasmataceaefamily -
Ehrlichia,Anaplasma, andNeorickettsia
Anaplasma traditionally refers to a disease of ruminants.
Obligate intraerythrocyticbacteria of the order Rickettsiales.
A phagocytophilum-formerly known as bothE equi-
predominantly in granulocytes.
A platys -infectious cyclic thrombocytopenia of dogs -platelets.
Ehrlichiacanis-Canine monocyticehrlichiosis-human
infection occasionally reported -monocytes.
E chaffeensis-monocyticform of illness in dogs.
E ewingii-primarily infects the granulocytes.
E muris–like (EML) agent -possible pathogen of dogs or cats -
currently unknown.

4. Epidemiology
E chaffeensisandE
ewingiihave sylvan cycles
in the environment that
involve tick species
(Amblyomma
americanum/lone star tick),
dogs and wildlife reservoir
hosts.
EML -Ixodesscapularis
(black-legged tick)
A phagocytophilum-Ixodes
scapularis(black-legged
tick)
A platys-R sanguineus-
CoinfectionwithE canis
(same tick vector).
E chaffeensis,E ewingii, andA
phagocytophilumare considered
zoonoses.

5. Clinical Findings
Acute E canis Chronic E canis
Warmer months-greatest activity of the tick vector
Depending on the strain of organism and immune
status of the host.
Reticuloendothelialhyperplasia
Fever
Generalized Lymphadenopathy
Splenomegaly
Thrombocytopenia (PetechiaeMay Not Be
Evident)
NormochromicAnemia; Leukopenia; Or Mild
Leukocytosis.
Vasculitisandtendeciesof IMHA/IMTP.
Variable signs of anorexia, depression, loss of
stamina, stiffness and reluctance to walk, edema of
the limbs or scrotum, and coughing or dyspneamay
be seen.
Cases May Present At Any Time
Of Year.
Marked Splenomegaly
Glomerulonephritis-Renal
Failure
Interstitial Pneumonitis
Anterior Uveitis
Meningitis With Associated
CerebellarAtaxia, Depression,
Paresis, And Hyperesthesia.
Severe Weight Loss
PancytopeniaWith Bleeding
tendencies
Dogs infected withA platysgenerally show minimal to no signs of infection despite
the presence of the organism in platelets. The primary finding is cyclic
thrombocytopenia, recurring at 10-day intervals.

6. Diagnosis Treatment
Combination Of
1.Clinical Signs
2.Positive Serum Indirect
Fluorescent Antibody (IFA)
Titer
3.PCR
4.Response To Treatment
Doxycyclinein dogs is 5–
10 mg/kg/day, PO or IV, for
10–21 days
Two doses of Imidocarb
Dipropionate(5–7 mg/kg,
IM), 2 wk apart
Supportive therapy -
Platelet or Whole Blood
Transfusions -if
hemorrhage is extensive.

7. Babesiosis
Intraerythrocyticprotozoan parasites of the genusBabesia.
Clinical disease in dogs is variable and can be sublinical, chronic,
or life threatening.
Large and small—based on intraerythrocyticform
A. Large (3–7 µm long; Single or pair tear-drop forms)
a.B gibsoni: worldwide
b.B conradae: southern California only
c.B microti-like: Spain
B. Small (1–3 µm long; Signet-ring form)
a.B canisvogeli: worldwide
b.B caniscanis: Europe
c.B canisrossi: South Africa
d.B coco: United States

8. Pathology
Intra-and extravascular
destruction of RBCs or
direct parasitic injury or
subsequent oxidative
stress or IMHA =
Hemolytic anemia
IMTPor DIC =
Thrombocytopenia
Lethargy
Pale mucous
membranes with icterus
Splenomegaly
pyrexia

9. PERIPHERAL Blood Smear
Canine blood smear of Babesiacanisshowing
paired large merozoites(pair tear-drop forms)
Canine blood smear of Babesiagibsoni
showing single merozoites(signet-ring form).

10. Diagnosis Treatment
Thrombocytopenia is the most
common feature regardless of
the babesiaspp.
Macrocyticanemia
Hyperglobulinemia
Hyperbilirubinemia,
Increased liver enzyme
activities, azotemia
Multiplex PCR (to rule out
coinfection), and DNA
sequencing
Imidocarbdipropionate(6.6 mg/kg
IM once, repeat in 7–14 days) -
Treatment of choice for B canis
vogeli(but is ineffective for
clearance of B gibsoniand B
conradae)
Pretreatment with Atropine (0.02
mg/kg SC 30 minutes before
imidocarb) reduces cholinergic side
effects (ie, salivation, lacrimation,
vomiting, diarrhea, tachycardia,
dyspnea)
Clindamycin(25 mg/kg PO q12h),
+ Metronidazole(15 mg/kg PO
q12h), + Doxycycline(5 mg/kg PO
q12h) have been associated with
clearance of B gibsoniafter
administration for ~3 months -true
treatment efficacy is unknown.
Diminazeneaceturate(3.5–7
mg/kg SC or IM q1–2wk) is
effective against B canis.

11. Cytauxzoonosis
Emerging, life-threatening infectious disease
of domestic cats (and dogs) -tick-transmitted
protozoan parasiteCytauxzoonfelis.
Cytauxzoonsppare classified as part of the
family Theileriidae(includes Babesiaand
Theileriaorganisms)
Dermacentorticks

12. Blood film from a cat
A –10X
Theleukocytecountisdecreased,andneutrophils
exhibitDöhlebodiesandincreasedcytoplasmic
basophiliaandvacuolationconsistentwith
moderatetomarkedtoxicchange(brokenarrows).
B –40X
Erythrocytesshowseveralsmallsignet-
ringbasophilicintracellularorganisms
consistentwithCytauxzoonorganisms
(arrows).

13. Cytauxzoonosis
Diagnosis Treatment
Anorexia, Dehydration, Pallor,
and Icterusare common.
Temperatures >105°F
Ataxia
Peripheral blood smear stain
(Giemsa)
NonregenerativeAnemia,
Leukopenia, and
Thrombocytopenia due to DIC
Hepatosplenomegaly, Pulm
Congestion or Cardiomegaly
with effusion.
Controversial-infection is
fatal
Supportive-aggressive IV
fluid therapy + blood
transfusions + Enoxaparin
to prevent DIC.
Medications
Standard of treatment has
yet to be determined.

14. HemotropicMycoplasmas
Previously known asHaemobartonellaandEperythrozoonand
formerly classified as Rickettsialorganisms.
Clinically significant Hemolytic Anemia -FELINE
INFECTIOUS ANEMIA (FIA)
REGENERATIVE ANEMIA IN DOGS AND CATS

15. HemotropicMycoplasmas
Transmission Clinical signs
Blood transfusion
Verticletransmission
(transuterine)
Horizontal transmission
(saliva, on gingiva, and on
claw beds of infected cats)
Vector borne (lice, flies,
ticks, and mosquitoes)
Coinfectionwith multiple
hemoplasmaspecies +
Feline Leukemia Virus
(FLV) or Feline
Immunodeficiency
Virus(FIV).
Acute Extravascular
Hemolytic Anemia.
lethargy, anorexia, and
fever, with splenomegaly
and icterus.

16. Diagnosis :
1. PCR
2. Blood Smear staining-
Romanowysky
Dog withMycoplasmahaemocanisinfection
Treatment
Doxycycline(10
mg/kg/day, PO, for a
minimum of 2 wk; with
water in cats)
Enrofloxacin(5 mg/kg/day,
PO) is a suitable alternative
to doxycycline.
Treatment of PCR-positive,
healthy cats is currently not
recommended
Immunosuppressive
dosages of glucocorticoids
to suppress immune-
mediated RBC injury.

17. Hepatozoonosis
Hepatozooncanis-transmittedbythebrowndog
tick,Rhipicephalussanguineus.
NorthAmerica-Hamericanum-transmittedby
theGulfCoasttick,Amblyommamaculatum-
AmericanCanineHepatozoonosis(ACH).
Eatingparatenic(transport;Ticks)hoststhatcontain
cystozoites-enterthevertebratehostviathegut.
Immunocompetentdogsappeartotolerateinfection
withHcanisverywell.

18. Clinical presentation
Depression
Muscleatrophy
Bloodydiarrhea
FluctuatingFever102.7°–106°F
Mucopurulentoculardischarge
Severehyperesthesiaorpainovertheparaspinal
regionisacommonfindingonphysical
examination
Dogs maintain a normal appetite if food is placed directly in front of them,
but they often will not move to eat, apparently owing to intense pain!

19. Diagnosis Treatment
Neutrophilicleukocytosis,
(WBC = 20,000–200,000
cells/μL).
A mild to moderate
normocytic, normochromic,
nonregenerativeanemia
Platelets -normal to high
Mildly increased ALP
Radiographs, periosteal
reactions -resemble those of
hypertrophic osteoarthropathy
PCR
No known therapeutic
regimen completely clears the
body of the organism.
TCP= Trimethoprim-
sulfadiazine(15 mg/kg, PO,
bid) + Clindamycin(10
mg/kg, PO, tid), +
Pyrimethamine(0.25
mg/kg/day, PO)
Decoquinatemay prevent
clinical relapses -10–20
mg/kg, PO, bid continuously
for 2 yr.
Imidocarbdipropionatetwice
monthly, @ 5–6 mg/kg, SC
Avoid corticosteroids

20. Trypanosomiasis
CHAGAS' DISEASE -Trypanosomacruzi
infection more common in dogs.
American trypanosomiasis–zoonotic–vector
borne disease -transmitted by Triatomine
(nocturnal and hematophagous) ‘kissing’ bugs
and caused byT cruzi.
>100 mammalian species (except in Avians!)
Dogs(insectivorous by nature) serving as a major
domestic reservoir.

21. Trypanosomiasis
Pathology
T cruzimaturation occurs in the bloodstreams and
anal odoriferous glands of dogs, and infective
trypomastigotescan be shed in feces or urine and
ingested.
1.Acute-lymphadenopathy, anorexia, pyrexia,
vomiting, diarrhea, and hepatomegalyor
splenomegalyand seizures.
2.Chronic phases
a)Latent -generalized weakness or sudden death.
b)Symptomatic –Right side-CHF –myocarditis+
arrhythmias + DCM –Death.

22. Trypanosomiasis
Diagnosis Treatment
Routine Peripheral Blood
Smear:
Giemsa stain,T cruziis an
extracellular, C-shaped
protozoan with a single
flagellum.
PCR
T. cruzi-Benznidazoleis the
drug of choice @ 5–10
mg/kg/day, PO, for 2 months.
Diminazeneaceturate@
dose of 3.5 mg/kg in T.
congolenseinfection; 7 mg/kg
in T. bruceibruceiandT. evansi
(Aquinos, 2007)
Quinpyraminesulphateand
Allopurinolhave also been
tried with a moderate success
rate –literature insufficient.

23. THANK YOU