Helminths of Small Animals I Flashcards
who do toxocara infect?
dogs
cats
who do ascaris infect?
pigs
people
where in the body do ascarididae reside?
small intestine
what animal(s) do Ascaris suum infect?
pigs
true/false: Ascaris suum have an indirect life cycle
false: direct
summarize the life cycle of Ascaris suum
infective eggs ingested
hatch in small intestine
L3 migrate intravascularly to liver, heart, lungs
burrow into bronchioles and migrate up
swallowed and mature and mate in small intestine
what animal(s) do Parascaris equorum infect?
horses
what animal(s) do Toxocara canis infect?
dogs
zoonotic
how does the life cycle/infection of Toxocara canis differ from that of Ascaris suum?
third stage larvae live in somatic tissues
transmammary and transplacental infection to pups
infection can occur by ingestion of paratenic hosts
what can migrating larvae impact?
viscera
eye
nervous system
what are the clinical signs of Toxocara canis?
not likely in older dogs
puppies: noisy breathing, cough, vomiting, diarrhea, stunted growth rate, distended abdomen
abdominal discomfort
death rarely due to obstruction/perforation
same in Toxocara cati
what is a way to identify Toxocara canis using a microscope?
cervical alae (clear cuticular flanges anterior end)
how can Toxocara canis and Toxocara cati be confirmed?
eggs in feces
how does transmission of Toxocara cati differ from Toxocare canis?
no transplacental transmission in cats
how can cats be infected with Toxocara cati?
ingest infective eggs
transmammary route
paratenic host
how can Toxocara cati be identified using a microscope?
cervical alae are broad and end abruptly
how can Toxocara canis be treated to keep newborn puppies from getting it?
dose bitch starting 3 weeks before and ending 3 weeks after birthing with fenbendazole
what animal(s) does Toxoscaris leonina infect?
dogs and cats
what other worm is Toxoscaris leonina similar to morphologically as an adult?
Toxocara canis: similar cervical alae
summarize the life cycle of Toxoscaris leonina
ingest eggs or L2 larvae (dogs) or paratenic host (cats)
larvae to mature adult in small intestine: no migratory phase
what are the clinical signs of Toxoscaris leonina?
not serious in light infections
heavier: diarrhea, dehydration, poor health, rarely death
how can Toxoscaris leonina be identified in feces?
eggs: thick, smooth outer shell, with empty space inside of egg
what animal(s) do Baylisascaris procyonis infect?
raccoons are host
zoonotic
summarize the life cycle of Baylisascaris procyonis
ingest eggs
larvae hatch and enter wall of small intestine
develop to adult worms in small bowel
what makes infection of Baylisascaris procyonis so pathogenic?
large and highly neurotropic
fatal nervous system disease
what are Baylisascaris procyonis’ diagnostic features?
prominent lateral alae
excretory columns
how does Nanophyetus salmincola make organisms sick?
bacteria called Neorickettsia helminotheca: gram-negative in Anaplasmataceae family
how is Nanophyetus salmincola transmitted?
eating undercooked/raw salmon, trout, pacific giant salamander
how is salmon poisoning disease treated and what are the clinical signs?
tetracyclines and praziquantel, albendazole, fenbendazole
high fever, weight loss, vomiting, diarrhea, lymphadenopathy, death 7-10 days
what parasites can cause visceral larva migrans?
Toxocara canis
Ascaris suum
Toxocara cati
what parasite causes fatal central nervous system disease?
Baylisascaris procyonis
what is the treatment for Baylisascaris procyonis in incidental hosts?
none, but anthelminthics may slow
what causes enlarged mesenteric lymph nodes, weight loss, vomiting, fever, and diarrhea?
Neorickettsia helminthoeca
disseminates in blood and lymph to lymphoid tissues
