Nematodes- General Flashcards
(22 cards)
Nematode general characteristics
- elongated body
- alimentary canal (organs)
- separate sexes (some spp males have bursa)
- direct or indirect life cycle
Identification
Necropsy for adults and larvae(L4, L5,
Key morphological characteristics: adults
- bursa, vulva
- buccal capsule, teeth
Key morphological characteristics: eggs
- round, oval, plugs, operculum
- thick or thin shell
- with or w/o L1 in fresh feces
Life cycle- Nematode
E-L1-L2-L3-L4-L5-Adult
-eggs come out in feces OR larvae come out in feces
Final host
the host in which the parasite becomes sexually mature
Intermediate host
parasite needs to grow a few stages in this host before infecting the FH to become sexually mature
Aberrant host
parasite is not meant to be in this host, cannot become sexually mature and usually causes some damage to the host
Accidental host
parasite not meant to be in this host but it can become sexually mature in the host
Paratenic host
parasites do not develop or grow in this host, they are just being transported (uber)
Direct life cycle
development of the parasite requires 1 host (no IH)
Indirect life cycle
development of the parasite requires at least 1 IH
Prepatent period (PPP)
the time it takes for the parasite to go from infection to sexually mature adult
Periparturient rise (PPR)
around the time of parturition, the nematode will greatly increase the # of eggs being put out into the environment to ensure survival rates of larvae development
-osis
parasite causing disease
-iasis
infected with parasite (could mean no clinical signs)
Predilection site
site of infection (where the parasite lives in the host)
Aberrant site of infection/infestation
site of infection in host that is not a normal place for the parasite to live
Egg ID: what to look for
- size
- shape
- shell
- larvae or morula inside
- bipolar plugs
- operculated
Hypobiosis (arrested development)
larvae go into a resting state inside the final host and stop developing, usually wait for a time the host’s immune system goes down to exit hypobiosis and continue development (ex. when a mom is pregnant, immune system goes down, pt exits hypobiosis)
Zoonotic parasites
Ancylostoma caninum, tubaeforme, braziliense Uncinaria stenocephala Toxocara canis, cati Baylisascaris procyonis Ascais suum Strongyloides stercoralis
Bottle jaw parasites
Bunostomum spp: anemia and d+ in YOUNG rums
Ostertagia: just d+ (cattle)
Teladorsagia: just d+ (shoats)
Haemonchus spp: just anemia
