Practical Parasitology Flashcards
What is a parasite?
Organisms that live on or in other organisms (called hosts) at the expense of the host
What are five non-chemical parasite management methods?
- rotate pastures
- cross-graze pastures with ruminants
- remove manure frequently
- harrow/drag pastures in hot, dry weather and keep horses out for two months
- avoid overstocking pastures
What are the two types of parasites?
Internal parasites
External parasites
What are endoparasites?
Internal parasites
What are ectoparasites?
External parasites
What are some internal parasites?
- Nematodes (roundworms, ascarids)
- Strongyles
- Cestodes (tape worms)
- Trematodes (flukes)
- Protozoa
- Bots
What are some external parasites?
- Lice (sucking and biting)
- Mites
- Ticks
- Flies
What are nematodes?
Roundworms
Ascarids
What are cestodes?
Tapeworms
What are trematodes?
Flukes
What are some common horse nematodes?
- Large strongyles
- Small strongyles
- Large roundworms
- Threadworms
- Pinworms
What color/size are adult roundworms?
Large and white
Roundworms can cause horses to….
look unthrifty, poor hair coat, some upper respiratory symptoms
Where do round worms live?
In the small intestine of young horses
Roundworm larvae ingested by horses hatch and undergo…
tracheal, liver and/or lung migration
Where do roundworms mature? How long does it take?
Small Intestine, 10-12 weeks
How many eggs do adult roundworms produce per day?
200,000
Where are adult roundworms passed on?
Manure
Life cycle takes about ______
3 months
Treatments for roundworm include ____ and _____
Fenbendazole
Pyrantel
_____ are the most damaging
Large strongyles
Damage from large strongyles may cause _____ - blood clot
an aneurysm
Which parasite?
Larvae migrate through internal organs of the host; may live in arteries; damage may cause an aneurysm
Large strongyles
____ are usually larger in number than large strongyles, can cause colic, diarrhea, rough hair coat
Small strongyles
____ life cycle requires no other organism except the final host to complete its life cycle
Direct
The direct life cycle includes most ____
equine nematodes
____ life cycle: parasite spend part of their life in an intermediate host and then are transferred to the host
Indirect
____ host such as mosquito or earthworm
Intermediate
Which parasite?
- Need an intermediate host to complete their life cycle
- Host is a forage mite
- Horse swallows infective mite and parasite mature in intestine in 6-10 weeks
Tapeworms
Tapeworms can cause ____ and disease
intestinal damage
Tapeworms firmly attach to certain areas of digestive tract, specifically ____ and ____
Small intestine and ileocecal junctions
Tapeworm attachment leads to ____, ____, ____, and ____.
inflammation, irritation, ulceration, and impairs normal function
Treatment for tapeworms includes ____ products
- ivermectin/moxidectin
- labeled for treatment not prevention
- if they have a high parasite load you could cause impaction
Praziquantel
Which parasite?
- smallest of nematode parasites (4-5 mm)
- affect stomach and small intestine, can cause bleeding in gut
- unique because adults can live in a free-living state
Hairlike worms
Why are hairlike worms unique?
The adults can live in a free-living state
Which parasite?
- Adults live in lungs - mate, eggs are coughed up and swallowed and passed with feces
- Hard to diagnose
- Most common in donkeys
Lungworms
Which parasite is most common in donkeys?
Lungworms
What are four methods of parasite control?
- Clean pastures/rotate
- Yearly fecal exams
- Washing a mare’s udder before foals nurse/regular basis
- Deworm young horses every 2 months starting at 6-8 weeks of age until 1 year old.
