02 - internal parasites in horses Flashcards
(internal parasites in horses)
- 4 Cx?
- dull hair coat
- unthriftiness
- colic and death
- decrease immune response
(internal parasites in horses)
(common equine parasites of concern)
(large strongyles)
- aka what?
- larvae penetrate the lining of the bowel and migrate where?
- bloodworms or redworms
- along the blood vessels that supply the intestines
(internal parasites in horses)
(common equine parasites of concern)
(large strongyles)
- infection with large strongyles can cause what 5 things?
- unthriftiness, wt loss, poor growth, anemia, colic
(internal parasites in horses)
(common equine parasites of concern)
(large strongyles)
- conrolled with what?
- avermectin deworming products
(internal parasites in horses)
(common equine parasites of concern)
(small strongyles)
- behavior different from large how?
- encysted larvae resistant to most dewormers
- don’t penetrate through intestinal wall or migrate through tissues
burrow into the lining of the intestine and remain dormant (encysted) for several months before completing life cycle
(internal parasites in horses)
(common equine parasites of concern)
(small strongyles)
- can cause what 5 things?
- colic
diarrhea
wt loss
slowed growth
poor coat condition
(internal parasites in horses)
(common equine parasites of concern)
(small strongyles)
- tx?
- fenbendazole at twice the standard dosing for 5 consecutive days
- moxidectin
(internal parasites in horses)
(common equine parasites of concern)
(roundworms)
- aka what?
- affect what age horses?
- ascarids
- young horses (< 10 months)
(internal parasites in horses)
(common equine parasites of concern)
(roundworms)
- can cause what if enough in intestine?
- obstruction
(internal parasites in horses)
(common equine parasites of concern)
(roundworms)
- roundworm larvae migrate though the internal organs until they reach what?
- lungs -> where they are coughed up and swallowed
(internal parasites in horses)
(common equine parasites of concern)
(roundworms)
- when should pregnant mares be dewormed?
- 30 days before foaling or at foaling to reduce foal’s exposure
(internal parasites in horses)
(common equine parasites of concern)
(roundworms)
- only what kind of roundworm can be passed thorough mammary gland in horses?
- threadworms
(internal parasites in horses)
(common equine parasites of concern)
(roundworms)
- Cx?
- coughing
poor body condition
rough hair coat
pot-belly appearance
colic
(internal parasites in horses)
(common equine parasites of concern)
(tapeworms)
- 2 Cx?
- colic, mild cramping
(internal parasites in horses)
(common equine parasites of concern)
(tapeworms)
- life cycle involves what?
- a tiny pasture mite -> so horses with access to pasture at greatest risk
(internal parasites in horses)
(common equine parasites of concern)
(tapeworms)
- tx?
- praziquantel
(internal parasites in horses)
(common equine parasites of concern)
(lungworms)
- can cause what?
- chronic coughing
don’t show any obviuos signs of infection
(internal parasites in horses)
(common equine parasites of concern)
(pinworms)
- lay their eggs where?
- on the skin around the horse’s anus
(irritation causes the horse to rub its tail repeatedly)
(internal parasites in horses)
(common equine parasites of concern)
(bots)
- not a major health problem
- can damage lining of stomach where they attach
- effective drug products?
- ivermectin
(internal parasites in horses)
- what are the four most troublesome equine internal parasites?
- large strongyles (bloodworms or redworms)
- small strongyles
- roundworms (ascarids)
- tapeworms


(internal parasites in horses)
(fecal egg counts)
- allows monitoring of anthelminitic effectiveness
- eggs per gram of 200 or less suggest what?
more than 500?
- negative sample doens’t mean horse is free (encysted small strongyes, tapeworms)
- light load
inneffective deworming and time to decrease interval between deworming
(internal parasites in horses)
(deworming)
- determination of deworming freq is best done by tx in 4 weeks with fecal egg counts
use this table!


