Blood Protozoa II

How would we describe Apicomplexa and what is an example

• blood coccidia

• Hepatozoon: the dog eats the tick

How would we describe Hemoflagellates and what is an example

(kinetoplastids) Trypanosoma, Leishmania: flagellates with a kinetoplast

The parasite is Hepatozoon americanum where does it live, what are the diagnostic stages and how does the dog get it?

• lives in: Gamonts in white cells; cysts in skeletal muscle

• diagnostic stage: Muscle biopsy (cysts, meronts); gamonts sparse in blood

• how does the dog get: Eats a Gulf Coast tick, or prey

The parasite is Hepatozoon canis where does it live, what are the diagnostic stages and how does the dog get it?

• lives in: Gamonts in neutrophils; meronts in spleen, marrow

• diagnostic stage: Gamonts in neutrophils

• how does the dog get: Eats a brown dog tick

The parasite is Trypanosoma cruzi where does it live, what are the diagnostic stages and how does the dog get it?

• lives in: Blood; heart and other tissues

• diagnostic stage: Blood forms (acute); serology (chronic)

• how does the dog get: Kissing-bug feces; eats a bug; dam to pup

The parasite is Leishmania infantumwhere does it live, what are the diagnostic stages and how does the dog get it?

• lives in: Macrophages

• diagnostic stage: Amastigotes in macrophages

• how does the dog get: Sand fly bite; dam to pup (US foxhounds)

What are the Two species of Hepatozoon

• H. americanum in the southern US,

• H. canis worldwide.

What are Hepatozoon:

a blood coccidium (Apicomplexa: a hemogregarine) of dogs.

What does Hepatozoon cause what disease

hepatozoonosis: fever, pain, muscle wasting.

Who is at risk for Hepatozoon

At risk: hunting dogs and dogs that roam outdoors.

What is the vector H. americanum

Gulf Coast tick (Amblyomma maculatum)

What is the vector H. canis

Brown dog tick (Rhipicephalus sanguineus)

How do dogs get H. americanum

Eating the tick, or prey with cysts

How do dogs get H. canis

Eating the tick; dam to pup

Where do you normally see H. americanum what region

Southern US

Where do you normally see H. Canis what region

Worldwide

Where do H. americanum live in (microscopically)

Gamonts in white cells (sparse); cysts and meronts in muscle

Where do H. canis live in (microscopically)

Gamonts in neutrophils; meronts in spleen, marrow

What disease do H. americanum produce

Severe, painful, often fatal

What disease do H. Canis produce

Usually mild; can be severe

What are the diagnosis for H. americanum

Muscle biopsy (most reliable); blood PCR may be negative

What are the diagnosis for H. canis

Gamonts in neutrophils on a smear; PCR

What are the Treatment for H. canis

Imidocarb

What are the Treatment for H. americanum

TCP or ponazuril 14 days, then decoquinate 2 years; NSAIDs

What is the control of H. americanum

Tick control; stop hunting and scavenging

What is the control of H. canis

Tick control; remove ticks promptly

Two species, two drugs. No treatment eliminates what

H. americanum: it prolongs life and reduces relapses.

The definitive host for Hepatozoon

• tick (Gulf Coast tick, Brown dog tick)

What is the intermediate host for Hepatpzoon

• dogs and coyotes

What is the paratenic host for Hepatozoon

• rodents

• rabbits

What is the first stage of Hepatozoon life cycle

• dog or wild canid swallows an infected Gulf Coast tick or infected prey

What is the second stage of Hepatozoon life cycle

• sporozoites leave the gut and reach the muscle

What is the third stage of Hepatozoon life cycle

• cysts in skeletal muscle; meronts release merozoites

What is the fourth stage of Hepatozoon life cycle

• gamonts in white blood cells

What is the fifth stage of Hepatozoon life cycle

• tick ingest gamononts; oocystts form in its body cavity, not the salivary glands

What are the American canine hepatozoonosis — clinical disease

• Cysts in the muscles rupture: pyogranulomatous myositis.

• Fever that comes and goes, pain, a stiff gait, reluctance to move.

• Muscle wasting, weight loss, mucopurulent eye discharge.

• Untreated, the dog can waste and die within months.

If we use CBC to test for American canine hepatozoonosis what do we typical find

Neutrophilia: up to 200,000/μL

If we use Chemistry to test for American canine hepatozoonosis what do we typical find

High ALP; CK often normal

If we use Radiographs to test for American canine hepatozoonosis what do we typical find

Periosteal new bone

How do we describe Trypanosoma cruzi and what does it cause

a hemoflagellate (kinetoplastid), the cause of Chagas disease.

What disease does Trypanosoma cruzi cause

myocarditis and heart failure in dogs and people: a zoonosis.

Where do you normally see Trypanosoma cruzi

southern US, especially Texas; Latin America.

Who is at risk for Trypanosoma cruzi

hunting, working and kennel dogs living outdoors.

What is the vector for Trypanosoma cruzi

Kissing bugs

Who are the host for Trypanosoma cruzi

Dogs, people

Who are the reserviors for Trypanosoma cruzi

opossums, raccoons, armadillos, skunks, wood rats

What is the route of infection on Trypanosoma cruzi (how do they get in)

Feces, not the bite (stercorarian)

What is the first stage of the LC of Trypanosoma cruzi

• kissing bug feces contain metacyclic trypomastigotes

What is the second stage of the LC of Trypanosoma cruzi

• feces contaminate a wound or mucosa (or the dog eats the bug)

What is the third stage of the LC of Trypanosoma cruzi

• amastigotes multiply in cells including the heart

What is the fourth stage of the LC of Trypanosoma cruzi

• blood stream trypomastigotes (do not multiply in the blood)

What is the fifth stage of the LC of Trypanosoma cruzi

• another bug ingest bloodstreams trypomastigotes

What is the sixth stage of the LC of Trypanosoma cruzi

• epimastigotes multiply in the midgut, metacyclic forms pass in the feces

What is occurring in the Acute (first month) phase in Chagas disease

parasites in blood, myocarditis, sudden death; worst in puppies

What is occurring in the Indeterminate phase in Chagas disease

no signs for months to years

What is occurring in the Chronic (in some dogs) phase in Chagas disease

arrhythmias, dilated heart, heart failure, sudden death

Amastigotes destroys what

heart muscle cells: myocarditis, then fibrosis.

What are the acute signs for Chagas disease

lethargy, big lymph nodes, pale gums.

What are the chronic signs for Chagas disease

exercise intolerance, fainting, ascites, arrhythmias.

Myocarditis or arrhythmias can cause what for Chagas disease in dogs

sudden death in any phase.

In the acute phase the parasite is Trypomastigotes in blood how do we test it

PCR or smear; serology may still be negative

In the Chronic phase the parasite is In tissues; few in blood how do we test it

Serology; confirm with a second test

In the phase of the heart the parasite is Myocarditis, fibrosis do we see and how do we test them

ECG, echo, troponin: damage, not the parasite

What is the treatment for Chagas disease

• treat the heart

• Benznidazole is an option (availability, toxicity); amiodarone with itraconazole has little evidence.

• No reliably curative protocol.

What is the control for Chagas disease

Insecticides and screens at kennels; screen donors and breeding females.

How do we characterize Leishmania infantum:

a hemoflagellate that lives inside macrophages.

What is the disease that Leishmania infantum causes

canine leishmaniosis; visceral leishmaniasis in people: a serious zoonosis.

Where do you find Leishmania infantum in the world ?

Mediterranean, Middle East, Latin America.

How does Leishmania infantum enter the US

foxhounds and imported dogs; a natural US sand fly cycle is unconfirmed

• Many infected dogs show no signs for years.

What is the first stage of Leishmania infantum

• sand fly deposist metacyclic promastigotes in the skin

What is the second stage of Leishmania infantum

• macrophages engulf parasites

• Dam to pup: important in US foxheads

What is the third stage of Leishmania infantum

• amastigotes multiply in a macrophages of skin and organs

What is the fourth stage of Leishmania infantum

• sand fly ingests amastigotes while feeding

What is the fifth stage of Leishmania infantum

• promastigote multiply in the fly gut and becomes infective metacyclic forms

What is the vector for Leishmania infantum

Female sand fly (Phlebotomus, Lutzomyia): tiny, hairy, wings held up in a V

What is the reservior for Leishmania infantum

dog

What is the route for Leishmania infantum

Injected by the bite

IN Canine leishmaniosis if we see Big lymph nodes and spleen; weight loss what do we see in the blood work and urine

Anemia; low platelets

IN Canine leishmaniosis if we see Non-itchy hair loss, around the eyes; ulcers, what do we see in the blood work and urine

High globulins, low albumin

IN Canine leishmaniosis if we see Long nails; nosebleeds; eye disease, what do we see in the blood work and urine

Protein in the urine

Immune complexes damage what ?

kidneys, joints and eyes.

What is the main cause od death in Canine leishmaniosis

Kidney disease is the main cause of death. Check urinalysis, UPC and renal function.

What are the diagnosis for Leishmaniosis

• cytology

• serology

• pcr

What is the treatment for Leishmaniosis

allopurinol with meglumine antimoniate or miltefosine; stage the kidneys. Dogs improve but are not cured.

The disease is Nagana what is the parasite

• parasite: T. congolense, T. vivax, T. b. brucei

How does Nagana spread by

Tsetse: biological (develops in the fly); T. vivax also by biting flies

The disease is Surra what is the parasite

T. evansi

How does Surra spread by

Biting flies: mechanical (no development)

The disease is Dourine what is the parasite

• T. equiperdum

How does Dourine spread by

Mating: venereal; no vector

What illnesses is produced by Nagana, surra:

in the blood: fever, anemia, wasting

What does dourine produce disease wise

(horses): mainly in tissues; swollen genitals, skin plaques, then paralysis.