Nematodes (Spirurida and Enoplida) Flashcards
Describe the life cycle of Dracunculus insignis.
- Parasite of the SQ tissues
- Female is very large (up to 120 cm)
- Male is smaller (40 mm)
- When the female is fertilized the anus and vulva atrophy and a shallow ulcer is formed in the host skin at the location anterior to the worm
- When the ulcer becomes wet she prolapses her uterus and expels larvae into water
- PPP= 1 year
What are the IH, DH, and paratenic hosts of Drancunculus insignia?
DH: Raccoon* and other carnivores
IH: Cyclops (copepod)
PH: Frogs
Nodular stomach worms that have donut-shaped anterior end that is covered in spines
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Gnathostoma spinigerium (Asia)
Describe the life cycle of Gnathostoma spp, including DH IH, and Paratenic host
- Adults are found in cystic nodules in the stomach
- Eggs are passed in 1 or 2 stage cells and develop to L2 in the water
- DH: Dogs and cats
- IH: Copepod (Cyclops) L3
- Paratenic: Amphibians, snakes, fish
- Migration of larvae causes a lot of damage
Describe the life cycle of Physaloptera spp.
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- Parasites of the stomach of carnivores
- Mouth is flanked by pseudolabia and surrounded by a cuticular collar
- Adults are white or pink in color
- Live with the anterior end embedded in the mucosa
- Cause vomiting
- Life cycle:
- Female worms lay small, thick-walled eggs. Larvae in the eggs will develop to the infective stage in various dung beetles crickets and other insects
- Various cold-blooded animals are paratenic
What are the treatment options of Physalptera in dogs and cats?
50 mg/kg fenbendazole x 3 days (dogs)
0.2 mg/kg ivermectin (cats)
5 mg/kg pyrantel pamoate X2 doses 3 weeks apart
This parasite is found in the esophagus and rumen of cattle, other ungulates, and occasionally bears and pigs
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Gonglyonema pulchrum- esophagus
Gonglyonema verrucosum- rumen
Usually harmless creatures
Describe the life cycle of Spirocera lupi, including hosts.
DH: Canids
IH: Dung beetles
Paratenic: Lizards, chickens, mice
When a dog ingests L3 they migrate to the adventitia of the visceral arteries and aorta to the walls of the esophagus & stomach
Ectopic nodules communicate with the lumen in the wall of the esophagus and/or stomach
What is the treatment of Spirocera lupi in dogs?
Milbemycin oxime (day 0, 7, and 28 days)
- Nodule disappeared between 95-186 days
- After no eggs seen after day 31 of the first treatment
What drug combination is used for the prevention of Spirocera lupi?
Milbemycin oxime + praziquantel monthly prevent 90% (Interceptor Plus)
What are the 3 most common stomach worms of horses in the USA?
Draschia megastoma, Habronema muscae, Habronema microstoma
Describe the life cycle of Habronema and Drashia spp.
- Larvae hatch from tiny eggs soon after they are laid; larvae or eggs present in feces
- Larvae are ingested by maggots and develop to L3 in 1 weeks
- IH: Musca domestica
- Habronema muscae
- Draschia megastoma
- IH: Stomoxys calcitrans
- Habronema microstoma
- Infective larvae accumulate in the labium
- When a fly lands on a warm moist surface, the larvae dispel
- Muzzle, ocular conjunctiva, cutaneous wounds
- Larvae are ingested and develop to adults in the stomach
- Those that enter through cutaneous lesions and form local granulomas
What is the treatment for Habronema and Draschia?
Ivermectin and Moxidectin
Where are the adult located in Pneumospirura sp. (canids)?
Parasites of the lungs
Superfamily Thelaziodea
Where do the adult nematodes reside in Metathelazia in canids?
Lungs
Superfamily Thelaziodea
What is the DH of Thelazia lachrymalis?
Horse
What are the DH of Thelazia skrjabini?
Horses and cattle
What is the DH of Thelazia gulsosa?
Cattle
What is the DH of Thelazia californiensis?
Dogs, sheep, and wild mammals
What is the IH for Thelazia sp. found in North America?
Outside North America in Japanese cattle?
North America: Musca autumnalis (Face fly)
Outside North America: Oriental face fly (Musca hervi)
What are the DH and I for Thelazia callipaeda in China and Italy?
DH: Human and Canines
IH: Fruit flies (Phortica and Amiota)
What are the IH for Thelazia californiensis?
Latrine flies; Fannia canicularis and Fannia benjamini
What are the treatments of Thelazia in cattle?
Doramectin 0.2 mg/kg SQ or IM
Tetramisole SQ 12.5-15 mg/kg
Levamisole 5mg/kg SQ or 1% aqueous solution
What are the treatments for Thelazia in dogs?
0.2 mg/kg Ivermectin SQ
1-2 drops moxidectin 1% OU
Topical moxidectin with imidacloprid (Advantage Multi)
Describe the life cycle of Dirofilaria immitus including with the IH
- Live in the pulmonary arteries
- Adults live up to 5 years
- 1/2 species in North America can transmit
- Larval development (L3) occurs in the Malpighian tubule before migrating to the salivary glands
- Molt to L4 (1.5 mm) 3 days after the bite and remain in the SQ and muscles of the abdomen or thorax for serval months
- Molt to L5 2-3 months after infection
- L5 migrate to pulmonary arteries by venous circulation (12-15 mm long)
- After reaching the right side of the heart the L5 (20-400 mm)mature and produce L1 6-9 months after infection
- 85-120 days after infection the are 3.2-11 cm
- Fertilized females occur 120 days post-infection, contain fully developed larvae 6 months after infection
- PPP=6-9 mths
- Microfilaria can live for up to 2.5 years
What parasite causes ocular and dermal dirofilariasis in Eurasia and Africa?
What are the DH and IH?
Dirofilaria repens
DH: Dogs
IH: Mosquitoes
What is the DH, IH of Oncocera cervicalis?
DH: Horses
IH: Culicoides
What is the difference in the location of adult versus microfilariae of Oncocerca cervicalis?
Adults: Deep connective tissue of nuchal ligament
Microfilariae: migrate throughout the SQ tissue of the dermis and connective tissue, including ocular conjunctiva
What is the treatment for Oncocera cervicalis?
Ivermectin IM- side effect is dying larvae can cause edema
Moxidectin
What is the DH and IH hosts of Oncocerca gutturosa?
DH: Cattle
IH: Simulium (Black flies) and Culicoides
What is the difference in the location of adult versus microfilariae of Oncocerca gutturosa?
Adults: Nuchal ligament
Microfilariae: dermis
What are the DH and IH are Onchocera lupi?
Where are the adults found?
DH: dogs
IH: Simulium tribulatum (black fly)
Adults are found in pea-sized subconjunctival granulomas or cysts in periocular tissue (SW USA)
What are the DH and IH for Onchocera lienalis?
DH: Cattle
IH: Simulium (Black fly) and Culicoides
What is the difference in location of the adults versus the microfilariae in Onchocera lienalis?
Adults: Connective tissue between spleen and rumen
Microfilariae: Dermis
What are the DH and IH of Acanthocheilonema reconditum?
DH: Dogs
IH: Flea; C. felis and amblyceran louse (Heterodoxus spiniger)
Where are the adults versus the microfilariae found with Acanthocheilonema reconditum?
Adults: SQ and fascia
Microfilariae: Circulating in blood
Often mistaken for D. immitus
What are the DH and IH of Acanthocheilonema dracunculoides?
What geographic regions are these nematodes found in?
DH: Canids
IH: Louse flies (Hippobosca longipennis, related to sheep keds) or Brown dog tick
Region: Africa, S. Europe, and Asia
Where are the adults versus microfilariae located for Acanthocheilonema dracunculoides?
Adults: Peritoneal cavity
Microfilariae: Circulating in the blood
What are the DH and IH for Cercopithifilaria grassii and C. bainae (Europe)?
DH : Dogs, but has a wide host range (baboon, bovids, opossum, porcupine, and rabbits
IH: R. sanguineus
Where are the adults and microfilariae found in Cercopithifilaria grassii and C. bainae?
Adults and microfilariae: skin
What are the DH and IH for Elaeophora spp?
Where are the adults and microfilaria found?
What geographic regions of the USA are these nematodes found?
DH: cervids and sheep
IH: Tabanids
Adults: arteries
Microfilariae: Dermis
exudative dermatitis with crust formation on the polls and faces of sheep sent to summer in altitudes >6000 feet in NM, AZ, and CO
What are the DH and IH of Setaria labiatopapillosa?
Where are the adults versus microfilariae found?
DH: Cattle
IH: Mosquitoes
Adults: Peritoneum
Microfilariae: Blood
What are the DH and IH of Setaria equina?
Where are the adults versus microfilariae found?
DH: Horse
IH: Mosquitoes
Adults: Peritoneal cavity
Microfilariae: Blood
What are the DH and IH of Parafilaria multipapillosa?
Where are adults and microfilariae found?
DH: Horses
IH: Haematotobia atripalpais
Adults: SQ and IM connective tissues in pea-sized nodules
Microfilariae: Eggs and microfilariae found in bleeding diathesis but never in circulation
What are the DH and IH of Parafilaria bovicola?
Where are adults and microfilariae found?
DH: Cattle
IH: Musca lusoria, Musca fasciata, and a third as yet undescribed Musca spp.
Adults in the SQ and IM tissue
Microfilariae and eggs in bleeding diathesis
What are the DH and IH of Stephanofilaria stilesi?
Where are the adults and larvae found?
DH: Cattle
IH: horn fly, Haematobia irritans
Adult and L1 are small and found in dermatitis lesions on the ventral abdomen of cattle
What nematode causes humpsores in cattle of India?
Stephanofilaria assamensis
Describe the life cycle, including hosts, of Dioctophyme renale
- DH: Dogs
- IH: earthworm
- PH: Fish and frogs
- Eggs are passed in the urine in one or two cell stages
- They develop in the water to L1 in a month or longer
- Larvated eggs (L1) are infective to oligochaete worms (earthworms)
- In the oligochaete worms that develop to L3 is the tissues
- Paratenic hosts: fish, frogs (do not undergo larval development in these hosts, L3 encyst)
- If a dog ingests an oligochaete worm, it will undergo the entire life cycle
- Right kidney or pelvis
What is the DH of Trichinella spiralis?
Pigs
What are the DH of Trichinella navita?
Artic species, bears
Can withstand freezing
Where is Trichinella nelsoni found?
sub-Saharan Africa
Where is Trichinella britovi found?
Euasia and N. Africa
Where is Trichinella murrelli found?
Neartic south of T. navita- North America to Mexico
Where is Trichinella patagoniesis found?
South America
Which species of Trichinella remain encapsulated in muscles fibers (nurse cell)?
Trichinella spiralis (pigs)
Trichinella navita (artic species (bears), can withstand freezing)
Trichinella nelsoni (sub-Saharan Africa)
Trichinella britovi (Euasia and N. Africa)
Trichinella murrelli (Neartic south of T. navita- North America to Mexico)
Trichinella patagoniensis (South America)
What are the hosts for Trichinella psuedospiralis?
Birds and mammals (unencapsulated)
What are the hosts for Trichinella zimbabwensis?
Repltiles and mammals (unencapsulated)
What are the hosts for Trichinella papulae?
Reptiles and mammals (unencapulated)
Describe the life cycle of Trichinella spiralis
- Larvae (L1) are found encysted in the tissue (striated muscle) and adults inhabit the GI tract
- L1 are liberated from tissue cysts by stomach juices, invade intestinal mucosa
- Both sexes reach sexual maturity in 2 days after infective meat is eaten 5 day post-infection, viviparous females give birth to prelarvae which enter the lymphatics and later the bloodstream to be transported to the muscle (image below of Knotts tets with prelarvae)
- When they first enter the striated muscle, they lie parallel to the long axes of the fiber and are easily overlooked
- After 2-3 weeks, they have completely develop to L1s and curl up in nurse cell
- Over time these cells will calcify
What is the treatment for Trichinella spiralis?
Albendazole
What are the 3 species of Trichuris that infect cats?
Trichuris felis
Trichuris campanula
Trichuris serrata
What species of Trichuris infects young cattle?
Trichuris discolor
What species of Trichuris infects young swine?
Trichuris suis
What is the treatment for Trichuris discolor in cattle?
Ivermectin, eprinomectin, doramectin
What is the treatment for Trichuris in sheep?
Ivermectin
What is the treatment for Trichuris suis?
Dichlorvos and Fenbendazole
What is the treatment for Trichuris vulpis?
Fenbendazole repeated monthly for 3 months
Milbemycin oxime
Febantel (within Drontal Plus)
Moxidectin
What is the treatment for Trichuris in cats?
No approved drugs, but possibly fenbental and fenbendazole
Where are E. boehmi adults located?
What is the DH?
What does the egg look like?
Location: Nasal capillariasis
DH: Foxes, dogs (canids)
The surface of E. bohemi egg is dented like a thimble and E. aerophilus is a network of anastomosing ridges; asymmetric bi-polar plugs
Where are Eucoleus aerophilus adults located?
What is the DH and facultative IH?
What does the egg look like?
Adults live in the bronci
DH: Dogs, cats, foxes
Asymmetric bi-polar plugs, the surface of E. bohemi egg is dented like a thimble and E. aerophilus is a network if anastomosing ridges
What is the treatment for Eucoleus aerophilus in cats?
Topical moxidectin & imidacloprid (Advantage Multi)
What is the treatment for Eucoleus boehmi?
Single-dose of ivermectin
Imidacloprid with moxidectin
What is the DH of Calodium hepaticum?
Where do the adults live?
Liver of rats, muskrats, woodchucks, wide range of other hosts including humans
Eggs deposited by females become lodged in hepatic tissue
Where are the adults for Aonchotheca putorii found?
What are the DH for this nematode?
Small intestine of bears, hedgehogs, raccoons, swine, bobcats, various mustelids, and sometimes domestic cats
Cause no harm, but eggs resemble other capillarids in cats that are pathogenic
Where do the adults of Pearsonema plica reside?
What are the definitive and intermediate hosts?
Bladder
DH: Canids (dogs, fox, wolf)
IH: Earthworm
What is the treatment for Pearsonema plica?
Ivermectin
What is the DH for Pearsonema felsicati?
Where does this nematode reside?
Urinary bladder of cats
What is the treatment for Pearsonema felsicati?
Fenbendazole
Where do the adult nematodes reside with Trichosomoides crassicauda?
What is the DH?
Treatment?
Urinary bladder of rats
Fun fact: Male lives inside the uterus of it mate
Ivermectin
Where do you find the adults of Anatrchosoma spp found in;
African monkey?
Virginia opossum?
Monkeys: Stratified squamous epithelium
Opposum: buccal mucosa
Where do the adults of Anatrichosoma cutaneum reside?
What is the DH?
SQ nodules and edema about the joints of the extremities and serpiginous blisters of the palms and soles of monkeys
Looks like CLM of Ancylostoma
Describe the life cycle of Acanthocephala?
When an egg is laid, it contains a fully developed acanthor
If the egg is ingested by a suitable arthropod IH, the acanthor develops through an acanthella stage into encysted larvae called a cystacanth
Cystacanths can re-encyst in a wide variety of vertebrate paratenic hosts
Frequently, cystacanth will re-encyst in its normal definitive host
What are the DH and IH of Macracanthorhynchus hirudinaceus?
Where do the adults live?
What is the treatment?
DH: Swine
IH (cystacanth): May beetle, dung beetles, water beetles
Treatment: No treatment is approved- Benzimidazole, Ivermectin, Doramectin
What are the DH and IH of Macracanthorhynchus ingens?
Treatment?
DH: Raccoons and black bears
IH: Millipedes
Treatment: Ivermectin
What are the DH and IH of Prosthenorchis?
Clinical signs?
Treatment?
- DH: Primates
- IH: Cockroaches and other beetles
- Clinical signs
- Chronic
- watery diarrhea of several months duration with weakness and progressive emaciation
- Appetite remains normal until the day before death
- Acute
- Secondary to bacterial peritonitis from penetration of proboscis
- Treatment:
- Fenbendazole
- Case report of failed treatment in a white footed tamarin with ivermectin
What are the DH and IH for Moniliformis?
DH: Wild rodents
IH: Cockroaches