Horse-helminths contd Flashcards
Shedding of GI nematodes in 1st year of life for foals
Considerations for deworming
-individual horse susceptibility and overall health
-geography
-pasture vs. stable
-number of horses per acre
-pasture vs stable
-number of horses per acre
-pasture management
-any known resistance
-owner risk tolerance
-weighing horses accurately to avoid underdosing
How do we prevent resistance?
- maintain and monitor drug efficacy
-which horses are biggest contributor of eggs
-leave parasite refugia
-monitor efficacy by FEC reduction test - use strategic treatments to max effect and minimize shedding
- Use non-drug methods of control (pasture and manure management)
Pasture and manure management
-dont relocacte dewormed horses to clean a pasture
-reduce stocking density
-dispose of manure regularly
-dont feed off the ground
-do not spread fresh manure on fields that horses graze
-mow and harrow pastures periodically
-separate weanlings from yearlings, adults
When should you always treat for parasites?
-coughing foal with no bacterial or viral cause
-diarrhea in 2-3 week old foal
-diarrhea, weight loss, low protein/albumin, edema
-spasmodic colic of unknown origin
-pruritus ani (explore non parasitic causes)
Oxyuris equi
-pinworms of horses
-cecum, colon, rectum, perianal region
-worldwide distribution
-stabled horses, and poor hygiene
-eggs environmentally resistant
-not zoonotic
Life cycle of Oxyuris equi
Diagnosis of oxyuris equi
-rarely flotation, usually swab or tape mount from perianal region
Treatment for oxyuris equi
-hygiene (environment and perianal washing)
-many labeled products
Onchocerca cervicalis
-connective tissue nematode
present in W. Canada where suitable climate and vectors = BC
-found in nuchal ligament
-can lead to fistulous withers
Onchocerca cervicalis lifecycle
Oxyuris equi eggs
Onchocerca cervicalis diagnosis
-microfilariae in skin histological section or culture from biopsy
-often no clinical signs
-Cutaneous onchocerciasis- in summer on ace, neck, ventral midline. Alopecia, crusting, pruritus
Treatment of Onchocerca cervicalis
ML will kill larvae but not adults
Dictyocaulus arnfieldi
-lung nematode
-rare in Canada
-not usually patent in adult horses but primary reservoir in donkeys and horses less than 3 yrs old
-pasture transmitted
-causes dyspnea and coughing