Lecture 4 1/26/24 Flashcards
What are the characteristics of nematodes?
-cylindrical and elongate
-pseudocoelomate/fluid filled body cavity w/ partial mesodermic lining
-usually dioecious
-complete digestive tract
-longitudinal muscles only
-covered by noncellular collagen cuticle
Which superfamilies fall within the order Strongylida?
-Ancylostomoidea/hookworms
-Strongyloidea/strongyles
-Trichostrongyloidea/trichostrongyles
-Metastrongyloidea/lungworms
What are the characteristics of the order Strongylida?
-males and females with buccal cavity
-males with caudal copulatory bursa
What are the characteristics of Ancylostomoidea/hookworms?
-“hook” anterior end curved dorsad
-large, heavily sclerotized buccal cavity with cutting plates/teeth/lancets
-feed by sucking blood
-thin-shelled eggs in morula stage
-live in small intestine
-often migrate within DH
What are the characteristics of Ancylostoma caninum?
-DH is dogs and wild canidae
-may use paratenic hosts
-males 11-13 mm
-females 14-21 mm
-eggs 55-65x35-40 um
-PPP of 2-3 weeks
What are the general characteristics of the Ancylostoma caninum lifecycle?
-eggs pass in feces and develop into infective L3 larvae in ~1 week
-penetrate skin and migrate to lungs
-larvae coughed up and swallowed
-remain within mucosa of small intestine before becoming adults
-transmammary infection from arrested larvae
What are the requirements for Ancylostoma caninum egg hatching?
-preferred temp of 72-86 degrees
-24 hours need
How long can Ancylostoma caninum survive in the environment?
a few months
What are the potential ways for dogs to become infected with Ancylostoma caninum?
-larvae in soil and infect through skin penetration or ingestion
-ingestion of mammalian paratenic hosts
-transmammary transmission
What are the clinical signs of Ancylostoma caninum?
-diarrhea/melena
-anemia
-hypoproteinemia
-emaciation
-dehydration
-respiratory signs
-death
What are the characteristics of peracute A. caninum disease?
-seen in transmammary infected pups
-anemia and pale mucosa
-deteriorate rapidly
-disease often sets in before eggs seen in feces
What are the characteristics of acute A. caninum disease?
-in older dogs
-often large numbers of eggs
-anemia and tarry stool
What are the characteristics of chronic A. caninum disease?
-asymptomatic with eggs in feces
-measurable reductions in RBC count
What is the treatment for Ancylostoma caninum?
-supportive care, including, fluids, warming, nutrition/vitamins, and blood transfusion
-parasiticide like pyrantel or fenbendazole
What are the characteristics of A. caninum larval leak?
-parasite migrates through lungs and enters somatic tissue or mucosa of small intestine
-arrested development/encystment of L3s
-arrested larvae activate after adult worm removal from small intestine or during pregnancy
How long do adult A. caninum worms live when untreated?
4-24 months
Which type of situation can be controlled with A. caninum, and which cannot?
-transmammary transmission can be controlled
-arrested larvae/larval leak cannot
How can pregnant dogs be treated in order to prevent transmammary transmission of A. caninum?
-treatment with fenbendazole or ivermectin
-daily doses leading up to whelping and while lactating
What are the characteristics of Ancylostoma tubaeforme?
-DH is cats and wild felidae
-males are 9-11 mm
-females are 12-15 mm
-eggs are 55-65x35-42 um
-PPP is 3 weeks
What are the clinical signs of Ancylostoma tubaeforme?
-diarrhea/melena
-anemia
-hypoproteinemia
-emaciation
-dehydration
-resp. signs
-death
What are the characteristics of A. braziliense?
-DH is cats, dogs, felidae, canidae
-males 5-8 mm
-females 6-9 mm
-PPP of 3 weeks
-eggs 60x40 um
-seen in tropics, Florida, Texas, Caribbean, and coastal US
What are the characteristics of Uncinaria spp.?
-DH is dogs, cats, foxes, wolves, fur seals, other carnivores
-males 5-9 mm
-females 7-13 mm
-significantly bigger eggs, 70-90x40-50 um
-PPP of 2-3 weeks
What are the characteristics of Uncinaria stenocephala?
-aka Northern carnivore hookworm
-less pathogenic than A. caninum
-ingestion transmission only
-cutting plates rather than teeth
-not zoonotic
-diagnosed through fecal flotation
What are the zoonotic manifestations of Ancylostoma spp.?
-cutaneous larva migrans: A. braziliensis
-eosinophilic colitis: A. caninum
What are the characteristics of Bunostomum spp.?
-DH is cattle, sheep, goats
-male is 10-17mm
-female is 16-26mm
-eggs 85x50 um
-PPP is 6-10 weeks
How can Bunostomum spp. be diagnosed?
eggs are larger and darker than most others seen in bovine feces
