Parasites

Question 1

Features of aphasmid nematodes are:

Answer 1

• Hypodermal bacillary bands
• Unapparent musculature
• Esophagus (small) with stichosome (large purple cell in the center seen in some cross sections).
• Single uterus (most nematodes have two)

Question 2

Examples of aphasmid nematodes are:

Answer 2

Capillaria contorta/annulata in birds (crop/esophagus). Capillaria xenopodis in frogs. Capillaria aerophilus (now it is Eucoleus aerophilus) in canids and cats. Capillaria hepatica in RODENTS AND SOUTHERN SEA OTTERS. Trichosomoides crassicauda (Bladder threadworm) IN RATS. Trichinella spiralis in pigs and bears.

Features are: phasmid nematode profiles with a prominent stichosome and hypodermal bands

Question 3

Rhabditiform nematodes have these histologic features:

Answer 3

Larvae have esophagus with corpus, isthmus, and bulb (“rhabditiform”), double lateral alae, and a notched tail. Adult females have smooth cuticle, meromyarian-platymyarian musculature, low cuboidal uninucleate intestinal cells, anterior cylindrical esophagus, retroflexed ovaries, and paired amphidelphic (folded on themselves) uteri.

Question 4

Examples of rhabditiform nematodes are:

Answer 4

Halicephalobus gingivalis in equids. Strongyloides sp in multiple species.

Question 5

Filarid nematodes have these histologic features:

Answer 5

Coelomyarian musculature, very small intestine (important diagnostic feature of filarids); small lateral chords and may have small internal cuticular ridge at the lateral chords. Microfilariae (all filarid species): Cuticle, appear to lack musculature, and are filled with myriad 1x2um basophilic nuclei (“bag of nuclei”)

Question 6

Examples of important filarid nematodes are:

Answer 6

Edesonfilaria malayensis and Dirofilaria spp. in old world monkeys. Dipetalonema and Mansonella (Tetrapetalonema) sp. in new world monkeys. D. immitis in canids/felids. Onchocerca cervicalis in horses. O. gibsoni in cattle. O.. lupi in dogs.

Question 7

Trichostrongylid nematodes have these features:

Answer 7

platymyarian musculature, longitudinal cuticular ridges, large intestinal tracts lined by few multinucleate cells.

Question 8

Examples of important trichostrongylids are:

Answer 8

Ollulanus tricuspis in cat (including non-domestic felids). Ostertagia ostertagi in cattle. Ostertagia circumcincta in sheep and goats. Nochtia nochti in NHP’s. Trichostrongylus axei in horses.

Question 9

Skrjabingylus nasicola is found in the nasal sinuses of what types of animals? What is the lesion it causes?

Answer 9

mustelids and skunks; it’s a nematode. Causes sinusitis with necrotizing osteomyslitis leading to perforation of the sinus bones of the skull

Question 10

Organisms that produce spherules:

Answer 10

Rhinosporidium seeberi, Coccidioides immitis, Chrysosporium parva/crescens, Blastomyces dermatitidis, Prototheca, Chlorella

Question 11

Schistosomes are digenetic _________.

Answer 11

trematodes

Question 12

Examples of schistosomes in animals are:

Answer 12

Heterobilharzia americana. Schistosoma mansoni in NHP’s. Schistosoma japonicum: NHP’s, dogs, cats, rabbits, rats, and domestic farm animals (cattle and sheep) Schistosoma bovis: Ruminants (portal/mesenteric veins) and occasionally horse, camel, pig.

Question 13

Clin path findings in animals with schistosomiasis:

Answer 13

Anemia, hypoalbuminemia, hypercalcemia (~50% of cases), +/- diarrhea

Question 14

Parasites associated with neoplasia:

Answer 14

(mnemonic SOCS-T)

Spirocerca lupi: Esophageal sarcomas in dogs

Opisthorchis , Clonorchis (Opisthorchis) sinensis (liver flukes): Cholangiocarcinoma in cats, NHPs, humans

Cysticercus fasciolaris (Taenia taeniaeformis): Hepatic sarcoma in rats

Schistosoma haematobium: Urinary bladder transitional cell carcinoma in humans

Trichosomoides crassicauda: Papillomas of the urothelium in rats

Question 15

What is the lung mite of macaques?

Answer 15

Pneumonyssus simicola

Question 16

2 tapeworms found commonly in catts?

Answer 16

Taenia taeniaformis and Dipylidium caninum