by W. David Wilson, MRCVS
What Can Your Veterinarian Do For
Parasite Control?
With a myriad of choices,
designing a worming program for your horse can prove
quite cumbersome. Unfortunately, the increased
availability of commercial parasite control has reduced
the role for veterinarians in the planning and
implementation of comprehensive programs.
Beware! Parasite control is complex and entails much
more than deciding which of many available anthelmintics
to select from the feed store or through the latest horse
supply catalogue. Your equine practitioner is the one
most qualified to address and oversee a program that best
protects the health of your horse and your individual
needs.
The following steps reveal how your veterinarian can
work with you in managing parasites for your horse.
Step 1--Initial consultation and assessment
You and your veterinarian should establish and
evaluate the following:
- financial capabilities of the owner
- compliance capabilities of the barn
- farm history
- geographic location and climate
- housing and management practices (number of
horses, feeding regimens, etc.)
- documented problems from the past
Step 2--Evaluation of the current parasite status
To more specifically evaluate the current parasite
situation, your veterinarian will likely collect, or ask
you to collect, two or three fresh fecal balls from at
least 20% of the horses on the farm. The horses chosen
should represent the spectrum age and management
practices employed on the farm. The results from the
fecal exam will provide a very useful guide to overall
status of the herd and degree of pasture contamination
and transmission potential.
Step 3 - Evaluation and correction
Did you know that you can eliminate most parasite
species from the environment through several management strategies, without the use of dewormers? For
example, the regular (at least twice weekly) removal of
feces from paddocks and pastures, either manually or
using tractor-powered vacuum units, has been shown to
greatly reduce the number of infective eggs and larvae.
Other strategies include:
- regular mowing and harrowing of pastures
(particularly during hot, dry weather and cold
weather) can break up manure piles and expose
eggs and larvae to the elements
- frequent rotation of horses to fresh pastures
- avoidance of overgrazing and overcrowding (more
than one horse per two acres)
- grazing horses with cattle and sheep
- making sure that supplemental feed is fed off the
ground
- keeping visiting horses separate from resident
horses and deworming before joining the herd
- constructing feeders so that horses cannot pull
feed onto the ground
- cleaning both feeders and waterers regularly to
minimize fecal contamination
- deworming mares one month prior to foaling
- thoroughly washing mares before foaling unless
precluded by weather conditions
- keeping mares and foals separate from other
horses
- reserving the cleanest, least-grazed pastures for
foals and other young stock