DEWORMING RECOMMENDATIONS FOR OUR AREA
RESISTANCE TO DEWORMERS IS A GROWING PROBLEM
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.
AN EVIDENCE BASED APPROACH TO DEWORMING
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.
BASIC DEWORMING SCHEDULE
Low Shedders:
April – FEC then Moxidectin with Praziquantel
October – FEC then Ivermectin with Praziquantel
December –Ivermectin if you see bots after October deworming
Moderate Shedders:
April – FEC then Moxidectin with Praziquantel
July – Strongid
October –FEC then Ivermectin with Praziquantel
December –Ivermectin if you see bots after October deworming
High Shedders:
April – FEC then Moxidectin with Praziquantel
July – Strongid
August – Ivermectin
October – FEC then Ivermectin with Praziquantel
December –Ivermectin if you see bots after October deworming
Foal Schedule
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:DEWORMING SCHEDULE for foals & yearlings (under 18 months old):
4 months Strongid
6 months Panacur
8 months Ivermectin w/Praziquantel + FEC*
10 months Strongid
12 months Panacur
14 months Moxidectin** w/Praziquantel + FEC*
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.
