01/16/2026
I truely have a love/hate relationship with Facebook posting. I can't stand how it chews up the links I post. So I'm going to try reposting the Dec. 25th posting of mixing up the wormers.
Changing up your Parasite Management on WORMING
I know that some of you guys wonder if I ever have any good news concerning your livestock. Well there is good news every once in a while I can share that, but unfortunately it's usually about something that can keep your herd safe. Well, I guess that is good news, Right? None of us have the money or care so little when a pet or herd member is lost. It can hit hard!
Here is a new article that deals with parasite safety, i.e. worming. I've seen medicine become less effective. It isn't the medicine, it is the parasites have become immuned. Much earlier in my livestock management, I was taught that you needed to switch meds at least twice a year (per the vet). But now they find that practice is still not enough.
So let's cover some basics, each of us needs to know.
Myth: I've wormed five weeks ago so now the stock are safe.
Fact: The wormers we can buy will not kill every type of parasitic worm.
Just because a wormer works for stomach and brown worms doesn't mean it will kill the poll barb worm. Each wormer kills different types of parasites; Ivermectin and Cydectin are in the macrocyclic which means they act by paralyzing the worms, which are then passed from the animal's body. Safe-Guard and Valbazen disrupt the digestive system of the worm, which kills it. If parasites are resistant to one class of drugs, it will be resistant to all drugs in the same class; if it has resistance to Ivomec, then it will also be resistant to Cydectin and so on.
We can achieve a higher efficacy and fewer resistant worms that survive the treatment, meaning less resistant worms with a combination treatment.
No, this does not mean you mix the two it means you give the animal two doses, one of each. Here is a great article that I highly recommend reading.
Before using this approach, there are a few precautions to be aware of.
1) In New Zealand and Australia, products are sold
that contain a combination of dewormers, so
only one product needs to be administered. In
contrast, in the US, no dewormers are yet sold in
this formulation, so the dewormers need to be
bought and administered separately. This increases the cost as compared to the products
available in these other countries. Additionally,
the different groups of dewormers are not chemically compatible, thus they cannot be mixed together in the same syringe. Rather, they need to
be administered separately, but can be given one
immediately after the other.
2) All dewormers should be administered at the full
recommended dose whether administered singly
or in combination.
3) When using dewormers in combination, meat
and milk withdrawal times will be equal to the
dewormer used with the longest withdrawal time
period.
4) If using dewormers in combination, it is critical to
maintain refugia; thus, one should be using a selective treatment approach based on FAMACHA©
(see FAMACHA© section of the ACSRPC website
(wormx.info) for more information on this method and for further explanations of refugia). The
presence of refugia is essential to realize the full
benefits from combinations. In fact, if refugia are
not maintained then you will not get the necessary dilution of the resistant survivors, and this
will then lead to having multiple-resistant worms
that can no longer be controlled with the combination treatment.
5) If the efficacy of your dewormers are more than
80 percent, it is possible you may not notice any
difference in the clinical response of treatments
when applied singly vs. in combination. However,
the impact on the further development of resistance could be quite large (see Table 2).
6) Any safety precautions that exist for a single dewormer will also exist when used in a combination; however, there are no known additional
risks with using more than one dewormer at the
same time.
Let's get year 2026 started with good practices management. 🐐