DEWORMING RECOMMENDATIONS FOR 2009
.
Recent
studies have shown that parasite resistance to the dewormers that we routinely
use is much more common than we suspected - and the problem is getting
worse. In spite of our best efforts to
take care of our horses we have actually contributed to this problem. By just following a deworming schedule
without first checking the worm burden in each horse and by using dewormers
with a greater frequency than is needed in many horses we have encouraged
parasite resistance. An example of the devastating effects of this trend can be
seen in sheep and goats where a deadly parasite has become over 90% resistant
to the only dewormer that we have available to treat it. Current deworming practices must be changed
to prevent this from happening in our equine population.
1) Use the correct drug for the correct
parasite at the correct time of the year.
2) Determine which horses require more or less
frequent treatment by performing a fecal egg count (FEC). Who are the high, low and moderate
“shedders” of parasite eggs in each group?
3) Evaluate the overall success of the worm
control program by monitoring the FEC of each horse at regular intervals.
FECAL
EGG COUNT
This
is a lab test that involves submitting a sample of feces from each horse. Place one fresh fecal ball in a ziplock bag
and label it with the horse’s name. The
sample may be collected the night before submission and stored in the
refrigerator. We will call you to
discuss the FEC results and deworming plan after determining which horses shed
a high, moderate or low amount of eggs. By performing routine FECs, we can
decrease the frequency of deworming to as little as 2-3 times per year for most
horses and avoid medicating horses that may not need it. Performing FEC at least in the spring and
fall is the only way to effectively monitor your parasite control program.
KEY
FACTS:
*
20-30% of the herd, the high and moderate “shedders”, are responsible for
harboring about 80% of the worms. These
horses are more susceptible to parasite infection and tend to remain this way
for life. It is important to identify
these horses with FECs and deworm accordingly.
*
Temperature matters: cold winter months and hot, dry summer months do not
support parasite larvae development. Horses with low worm burdens do not need to be dewormed during these
months. Spring and fall are optimal
times for parasite development, and treatments should be focused on these
months.
*
Harrowing or dragging pastures kills worm eggs by exposing them to the dry heat
of the summer. After the temperatures
become cooler in the fall (below 80 degrees), harrowing actually helps the
worms multiply by spreading their eggs.
DEWORMING AND FEC SCHEDULE
for horses over 18 months old:
TO DETERMINE PARASITE LOAD AND EFFICACY OF DEWORMERS
APRIL 1 -
First, perform a fecal egg count (FEC) on each horse to classify them as a low, moderate or high shedders. Then treat all horses regardless of the results of FEC results.
Use Moxidectin w/ Praziquantel (Quest plus). Moxidectin is preferred because it lasts 4-6 weeks longer than Ivermectin and removes encysted strongyles which are buried in the gut and can cause disease as they emerge in the spring. Praziquantel is used to remove tapeworms twice a year.
JULY 1 -
Treat moderate and high
shedders with STRONGID .
Repeat a FEC 14 days after
treatment to determine
efficacy of strongid.
August 1 -
Treat only high shedders with IVERMECTIN.
OCTOBER 1 -
Perform
a fecal egg count on each horse to determine program efficacy.
Treat all horses regardless of FEC resultswith
IVERMECTIN w/ PRAZIQUANTEL
DECEMBER 1 -
Treat with Ivermectin if concerned about bots after Oct 1st or the weather is relatively
warm.
SPECIAL CIRCUMSTANCES
* New arrivals to the herd with an unknown deworming history should have a FEC done followed by treatment with 5 days of Fenbendazole (Panacur Power Pac). Use Ivermectin on the 6th day of treatment. At least 14 days later another FEC should be performed and that horse can then be incorporated into the herd deworming program.
* Horses visiting for less than 6 weeks can be treated with a single dose of Ivermectin.
DEWORMING SCHEDULE For Adult Horses
Continue to check
fecals at least twice a year to ensure efficacy
| April | July | August | Oct | Dec | |
|---|---|---|---|---|---|
Low Shedders <150 |
FEC Moxidectin w/ Praziquantel |
FEC Ivermectin w/ Praziquantel |
Ivermectin if had bot eggs after October treatment
-or-
Weather is
relatively warm.
|
||
Moderate Shedders 150-500 |
FEC Moxidectin w/ Praziquantel
|
Strongid Wait 14 days FEC |
FEC Ivermectin w/ Praziquantel |
||
High Shedders >500 |
FEC Moxidectin w/ Praziquantel |
Strongid Wait 14 days FEC |
Ivermectin |
FEC Ivermectin w/ Praziquantel |
DEWORMING SCHEDULE for foals & yearlings
(under 18 months old):
Start deworming at 2
months of age. Begin with a FEC, then
give Ivermectin regardless of results. Follow up with deworming every 2 months with:
6 months Panacur
8 months Ivermectin
10 months Strongid
12 months Panacur
14 months Moxidectin**
16 months Strongid
18 months Panacur
*Perform FEC at least 14 days after
treatment
**Moxidectin (Quest)
is safe to use in foals 6 months and older if dosed according to
instructions
After 18 months of age all horses can be
incorporated into the herd program.
.
Please call with any questions. We are happy to help you with a deworming plan.