7/8: Parasites Flashcards
(31 cards)
What is a parasite?
An organism that depends on a host to survive and spread
What is an endoparasite?
A parasite living inside host’s body
What is an ectoparasite?
A parasite living outside host’s body
What phylum and class are tapeworms in horses part of?
phylum: platyhelminths
class: cestoda
name three examples of tapeworms in horses
anoplocephala (a.) perfoliata
anoplocephala (a.) magna
paranoplocephala (p.) mamillana
how does one diagnose tapeworms in horses and why is it difficult?
through faecal egg detection, difficult as absence of eggs in faeces does not mean absence tapeworms are absent.
describe the body plan of tapeworms in horses
scolex (head) has four suckers
strobila (tail) is flattened and segmented with various body systems
most posterior segment contains eggs
what are potential means of removing tapeworms in horses and how effective are these?
- no drugs completely remove tapeworms, only up to 70% removal
- vets recommend double dose of drugs 1-2 times per year
-> may however harm pregnant/breeding animals
what is taenia solium?
pink/pork tapeworm
how long does the pink tapeworm get?
up to 7m long; half the length of bovine counterpart
how is the pink tapeworms scolex built?
double row of hooks
what are clinicals signs of pink tapeworms?
large cysts in brain + other organs, can be life threatening
what causes worm infections?
uncooked/contaminated meat, untreated sewage
how can worm infections be detected?
worm segments/eggs in faeces
what is psoroptes ovis?
sheep scab
what are clinical signs of sheep scab?
- mites feed on skin
- sheep develop raw patches
- skin hardens
- sheep scratch
what are lucilia cuprina?
sheep blowfly (australian blowfly)
what is a blowfly strike?
blowflies attacking sheep in large numbers
how do blowflies inflitrate sheep and how do they reproduce?
- lacerate skin using anterior hooks
- digest tissue by secreting proteolytic enzymes
- lay eggs on soiled fleece/wounds
- breed on carcasses
- eggs develop into maggots and feed directly onto infested sheep skin
how can you treat a blowfly strike and prevent secondary infections?
soaking w organophosphates and grazing in open pastures, removal of dead bodies
what are ixodes ricinus?
sheep ticks
what are some disease causing agents that sheep tick transmit?
- water fever in cattle
- louping ill virus in sheep
- lyme’s diseasse in humans
describe the life cycle of a tick
- need moisture + shade: tend to live in woodland + bracken
- eggs hatch into larvae in early spring
- larvae attach to passing bird/mammals
-> feed on blood for 3-4 days - drop onto soil and stay for months, emerge as nymphs
- attach to host, feed for months to mature
- female adult 2-3mm and flat -> increase to size of baked bean when done full
- pass pathogens on to host causing diseases
how do you prevent sheep ticks and their diseases?
pesticides, selective breeding, vaccination against pathogens
