Helminths (Superfamily Metastrongyloidea) Flashcards
Georgi's (58 cards)
What are Metastrongyloids?
Parasites of the respiratory, vascular, and nervous systems of mammals
Most species require a snail or slug intermediate host, but some can infect directly.
In which family is the genus Metastrongylus found?
Family Metastrongylidae
Contains large white parasites of the bronchi and bronchioles of swine.
What is the characteristic of the mouth in Metastrongylus?
Flanked by a pair of trilobed lips
The spicules are long and thin.
What type of eggs do oviparous females of Metastrongylus lay?
Eggs containing first-stage larvae
These eggs typically do not hatch without being ingested by an earthworm.
What is the economic and pathological importance of Metastrongylus spp.?
Of only modest importance
They were once thought to act as vectors for swine influenza virus, but proof is lacking.
Name three approved anthelmintics for swine lungworms.
- Fenbendazole
- Levamisole
- Ivermectin
Doramectin is also approved.
What is a key identification feature of Protostrongylids?
Well-developed bursa, spicule, and spicule guide
The vulva is also near the anus.
What type of eggs do oviparous protostrongylid females deposit?
Unsegmented eggs in surrounding lung, vascular, or neural tissues
These develop into first-stage larvae before appearing in feces.
Where does Protostrongylus rufescens live?
In the smaller bronchioles of sheep and goats
It may cause localized lesions.
What is the treatment for M. capillaris infection in sheep?
Moxidectin (1% injectable solution at 0.2 mg/kg)
In goats, topical eprinomectin (0.5 mg/kg) is used.
What is the typical host for Parelaphostrongylus tenuis?
White-tailed deer (O. virginianus)
It rarely causes disease in this species.
What type of signs indicate Parelaphostrongylus tenuis infection in abnormal hosts?
Neurologic signs
This can lead to serious or fatal disease.
What is the identification feature of Crenosomatidae?
Well-developed bursae with a large dorsal ray
The uterus is amphidelphic with a prominent ovijectoral sphincter.
What is the life history of Crenosoma vulpis?
Oviparous females deposit first-stage larvae or thin-shelled eggs containing them
These develop into infective third-stage larvae in snails and slugs.
What is a successful treatment for Crenosoma vulpis infection in dogs?
Fenbendazole (50 mg/kg daily for 3 to 7 days)
A single treatment with milbemycin oxime was also effective.
What characterizes the family Angiostrongylidae?
The bursa may be somewhat reduced, but rays are well defined
The vulva is near the anus, and the uterus is prodelphic.
What is a key feature of Aelurostrongylus abstrusus?
Oviparous female deposits unsegmented eggs in ‘nests’ in lung parenchyma
These appear as small, grayish white subpleural nodules.
How do cats typically become infected with Aelurostrongylus abstrusus?
Predation of paratenic hosts that consume snails
Mice and possibly birds may serve as paratenic hosts.
What percentage of cat fecals were found positive for Aelurostrongylus abstrusus in a survey?
6.2% of 1322 cat fecals
This was from shelters in upstate New York.
What percentage of cat fecals from shelters in upstate New York were found positive for A. abstrusus?
6.2%
Based on a study conducted by Lucio-Forster and Bowman in 2011.
What was the prevalence of A. abstrusus found in a national survey of feline fecal samples examined at IDEXX Laboratories from 2008-2017?
0.15%
This prevalence was primarily observed in the Northeast, Great Lakes area, and West Coast.
What geographic factor was noted in the antibody detection assay for A. abstrusus in Switzerland?
90.3% of positive cats were from elevations below 700 meters above sea level
98.9% were from areas with mean temperatures above –2°C in January.
What clinical signs may be associated with moderate A. abstrusus infection?
Coughing and anorexia
Severe infections can lead to cough, dyspnea, and polypnea.
What percentage of cats that died during a spay-neuter program in New York State were found infected with A. abstrusus?
9%
This was determined during necropsy examinations.
