INTESTINAL PARASITES

Most common types of intestinal Parasites

• Strongyles (Bloodworm or redworm)

• Ascarids

• Tapeworms

• Bots

horse becomes infected when

• turned out with previously infected horses

• turned out with contaminated pasture

blood worms or red worms

Strongyles

Redworm

Strongyles

Bloodworm

Strongyles

Lifecycle of Strongyles

Infection occurs by ingestion of larvae

which transform into adult

travel down to intestinal tract

Species of Strongyles

• Strongylus vulgaris

• Strongylus edentatus

• Strongylus equinus

• Strongylus vulgaris causes

• damage the cranial mesentery artery

• colic

• possibly rapture

• gangrenous enteritis or intestinal stasis

• Strongylus edentatus

• Strongylus equinus

• causes

active blood feeder

cause

• Weakness

• Emaciation

• Anemia

• Diarrhea

active blood feeder

• Strongylus edentatus

• Strongylus equinus

Roundworm

Ascarids

Ascarid also known as

Roundworms

common Ascarids (roundworm) in equine is

Parascaris equorum

Ascaris (Roundworm) lifecycle

• Larva start growth in the small intestine

• then migrate through the liver, lungs, and finally the pharynx pr throat

• then get swallowed again

• return to small intestine to mature and reproduce

Problem with young horses up to 15months old due to lack of immunization against worms

• weight loss

• stunting

• rough hair coat

• pot-bellied appearance

• lethargy or colic

Ascaris (Roundworm)

• pot-bellied appearance

Ascaris (Roundworm)

infective stage in Ascaris (Roundworm)

3rd stage

Example of tapeworm (flatworm) in horse

Anoplocephala magna

other term for tapeworm

flatworm

lifecycle of Tapeworm (flatworm)

• forage mites eat tapeworm egg

• larvae develop inside the mite

• horse ingest the mite during grazing

• larvae develop inside the gut into maturity

• adhere to gut wall at the ileo-cecal junction

• intestinal obstruction or rupture due to inflammation

Bots (larva of fly)

(larva of fly)

lifecycle Bots (larva of fly)

• adult flies’ lays eggs on the horse’s legs, chest and shoulder

• horse obtain the egg when it grooms itself

• larvae enter the mouth

• larvae travel and attach to lining of stomach

• causes irritation, digestive problems and obstruction

• larvae passed in the feces after 8-10 months

• burrow to the ground to pupate

• surface from the ground as adult flies

common signs of parasitic infection

LLLLCDD

• lethargy

• loss of weight

• loss of condition

• lack of appetite

• colic

• diarrhea

• dull coat

Diagnosis of Intestinal parasites

1. Fecal egg count- species of parasite and extent of infestation

2. Blood test- measure chemicals in blood produced by inflammatory responses to the migration of larvae

steps for effective parasitic control

• Pasture management

• monitoring fecal egg count

• deworming program

decrease the amount infective eggs and larvae from the pasture

pasture management

Pasture management 5 steps

decrease the amount infective eggs and larvae from the pasture

A. remove and dispose of the feces from the pasture at least 2x a week

B. Mowing and harrowing the pasture will expose the larvae to elements and predators

C. Pasture rotation- rest pasture for at least 6 months

D. Keep number of horses per acre to a minimum

E, Supply hay or grain in rack rather than from ground

diagnose parasites as well as determine effectiveness of worming program

monitoring fecal egg count

to remove the adult worms and reduce the chance of reinfection

deworming program

Classes of dewormers

1. Benzimidazoles

• Fenbendazole

• Oxibendazole

2. Macrolide Lactones

• Ivermectin

• Moxidectin

3. Tetrahydropurimidines

• Pyrantel Pamoate (Embonate)

• Pyrantel Tartrate

4. Iscoquinoline-Pyrozine

• Praziquantel

Praziquantel

Iscoquinoline-Pyrozine

Iscoquinoline-Pyrozine

Praziquantel

Tetrahydropurimidine

• Pyrantel Pamoate (Embonate)

• Pyrante Tartarate

• Pyrantel Pamoate (Embonate)

• Pyrante Tartarate

Tetrahydropurimidine

Macrolide lactones

• Ivermectin

• Moxidectin

• Ivermectin

• Moxidectin

Macrolide lactones

it kills/focus the roundworm

• Pyrantel Pamoate (Embonate)

• Pyrantel Tartrate

Benzimidazoles

• Fenbendazole

• Oxibendazole

• Fenbendazole

• Oxibendazole

Benzimidazoles

if you double dose this kind of dewormer it can also kill the tapeworm

3. Tetrahydropurimidines

• Pyrantel Pamoate (Embonate)

• Pyrantel Tartrate

factors to consider when determining which dewormer to use

1. horse age

2. fecal egg count reduction test

3. use only dewormers necessary for worms detected in the fecal egg reduction test

4. use weather and climate to your benefits

5. follow dosage direction

6. question on worming schedule should be discussed with the veterinarians

2 types of deworming programs

• continuous deworming

• strategic deworming

feeding a daily dewormer year-round or throughout the grazing season

• continuous deworming

the concentration of the drug is low and it result resistance

• continuous deworming

like a purge deworming

• strategic deworming

deworming only at certain times of the year or when fecal egg count rise

• worms

• lungworms,

• ascaris,

• summer sores

• bots

• strategic deworming

traditional worming is every

2 months

Administration of dewormers

1. oral paste

2. feed additive (powder, liquid, or pellet dressed over the grain)

** Powder with corn oil or dilute to water

3. nasogastric (Stomach) tube

universal drug that can kill both nematode and cestode

Praziquantel (Iscoquinolone-Pyrazine)

Parasites reside or attached to the ileo-cecal junction

Tapeworm

Parasites reside or attached to the lining of stomach

BOTS