N ow that spring is here and pastures are starting to grow, we get more questions about diarrhea, poor hair coats, and lower weight gains.
Everyone wants to know: “What is the best dewormer ?”
The appropriate answer is that first of all, one must verify parasites as the primary cause of the clinical signs.
Next, determine which parasite is the problem. Then select a dewormer that should be effective, and more importantly, confirm that it still works on your farm.
All of these steps are critical to ensure an effective treatment and management program for your herd.
Verifying that the causative agent is parasites is very easy and inexpensive. With the cost of some of the dewormers on the market, you want to know what is best to utilize before you throw away money and treat with the wrong product.
Running a simple Parasite Flotation Test, or Fecal Egg Count, is the quickest way to see if you have a parasite issue. All this test requires is the collection of some fresh fecal samples for your veterinarian to examine. You need multiple samples since different individuals will shed eggs at various rates over different times.
The advantage of performing fecal tests is that it also will determine the type of parasite. This is an important step since I have seen many occasions where clients go to the farm store, buy a dewormer for one parasite such as stomach worm, but the problem is actually coccidian infection. These two parasites are treated with two completely different medications.
By knowing that a parasite issue exists and identifying which parasite, your veterinarian can determine which product, or products, may be the right choice for your facility. Many products are made that have diverse coverage and various ways of administration, so you can study these options to determine the best approach to your farm’s program.
Finally, a much overlooked part of parasite programs historically, is following up to make sure the parasite treatment and prevention program is working.
The best way to check is to run a Fecal Egg Count Reduction Test (FECRT). This involves performing a fecal egg count just prior to deworming, and then retesting around 10-14 days after deworming. If your dewormer is working, you should see a significant drop in egg counts. Once the egg counts fall, running a periodic random test to make sure you’re still on track is important.
Every farm is different and may have other parasite management tools and options available, such as pasture rotation, to use in conjunction with dewormers. Your veterinarian will be able to work up a program catered to your farm and give you the best protocol to use.
Editor’s note: Stephen Foulke, DVM, DABVP (Dairy) is a board certified specialist in dairy practice with Agricultural Veterinary Associates in Lititz. He can be reached at 717-625-4212.