Blood parasites Flashcards
Babesia canis locations and host tick
North America; rhipicephalus sanguineous
Babesia gibsoni
North America, NO HOST TICK, transmission by infected blood from fighting
Basics of Babesia
in RBC, trophozoites in red cells, piroplasms are feeding stage (tear drop paired in canis and singly in gibsoni)
Life cycle of Babesia
Merozoites taken up by tick, undergo gametogony in tick to sporozoites, dog is infected when tick feeds (this is all like coccidia), erythrocytes are the ONLY host cell parasitized in the dog, piroplasms reproduce asexually. Transplacental transmission occurs
What is the infective stage versus the feeding stage of
Babesia?
Sporozoites versus trophozoites (also diagnostic stage)
How are Babesia organisms transferred in the tick?
Transovarian and transstadially
How do you diagnose Babesia?
Difficult, by blood smear to find piroplams, serology, or most accurate PCR
Treatment for Babesia?
Imidocarb diproprionate (will not clear), and combo therapy of azithromycin and atovaquone (only possibility of clearing B. gibsoni); use tick control for B. canis
Cytauxzoonosis
Protozoan found in Mid-Atlantic and Mid-west states; bobcats are natural reservoir hosts. Sporozoites invade endothelial-associated mononuclear phagocytes which undergo schizogony and adhere to wall. Diagnose with piroplasms
What is the tick associated with Cytauxzoonosis?
Amblyomma americanum
What is the pathology asso. with Cyt?
primarily from the tissue phage, histiocytic macrophages attach to vessel wall and cause obstruction
What is the major clinical sign asso. with Cyt?
body temperature is very high and then drops below normal after 3-6 days
Treatment for Cyt?
Unrewarding, supportive therapy, atavoquone and azithromycin combo–too much tissue damage has already occurred by the time it is initiated
Hepatozoon americanum
Fatal tickborne disease in southern US. Amblyomma maculatum is the tick. Dogs become infected by EATING the tick! Coyotes important reservoir
Classic pathology of H. americanum
Schizogony in phagocytic cells between myocytes (classic onion skin appearance). Also called granulomatous myositis with extensive atrophy–>pain
Diagnosis of H. americanum
Neutrophilic leukocytosis, lifelong infection in dogs
Trypanosomes
lives in blood stream, lymph, and tissue spaces. Transmitted by blood sucking arthropods
Trypanosoma cruzi
Dogs in southern US, transmitted by kissing bugs. Metacyclic trypomastigotes shed in insect feces. Amastigotes in tissues replicate in cardiac and smooth muscle.
Pathology of T. cruzi
Myocardial disease proportional to amastigotes in cardiac muscle. Heart disease is ultimate cause of death
Diagnosis and treatment of T. cruzi
usually based on serology. MUST contact CDC if find disease in order to get drug
Is T. cruzi zoonotic?
Yes, Chagas’ disease is most common cause of CHF in world
What are the five neglected parasitic infections?
Chagas disease, cysticercosis, toxocariasis, toxoplasmosis, trichomoniasis
Dipetalonema reconditum
SQ tissue of dogs, southern US, will be less than 270um. **do not confuse with heartworm. decreased in prevalence due to flea control
Dracunculus insignis
SQ tissues, raccoon is normal host, females associated with skin ulcers. Females deposit L1 into water, gets taken up by copepod and develops into L3, host ingests PH and the larvae migrate through intestine to get to SQ. Treatment is surgical removal, disruption of worm leads to anaphylaxis!
