Tag Archives: drug resistance

Drug Resistant Parasites in Goats Part III

12 Sep

With so many different opinions and not getting any closer to a solution on how to protect my goats from parasites, I finally called the vet I work with most on my goats and requested he come to my farm for a consultation.  It was the best thing I could have done.  Instead of just stopping in the office and having distractions, it gave him a chance to review the literature.  It also gave me time to review all my records, and when he arrived, I could fill him in on all the details, rather than the hit-and-miss that comes with working with multiple vets.  If you’re just joining me in this series, you might want to read

Part I
Part II

What I Had Been Doing

What I had been doing was using the herbal wormer on my adult goats.  Towards the end of summer, I would have a couple of goats I’d have to worm.  This time of year my pasture isn’t as good a quality (especially in drought years) and they are still raising babies.  Kizzy and Dolly get wormed almost every summer.

Kizzy and Little Bit

Kizzy and Little Bit

Most of my adults haven’t been given a chemical wormer in quite some time.  In fact, Meg hasn’t had a chemical wormer since 2008.  I have things under control with the adults by using the herbal wormer and an occasional worming when someone is sick or run down with kids.  Of course, with Iowa State telling me I can’t use Cydectin or it will be ineffective, I didn’t know what to do this summer when I had four goats that I wanted to worm, so I hoped they could hang in until I had the consultation with my vet.

Clover Blackboer

Clover Blackboer avoiding the heat

The kids are my main problem.  I had been worming them all with a chemical wormer (Ivomec) between ages 6 and 8 weeks.  That’s what I did this year with the Valbazen, but it didn’t work for all of them.  In the past, by the time they would need wormed again, they would be solidly on the herbal wormer.  This worked well until the Ivomec quit working and the Iowa State Vets told me I couldn’t use Cydectin without it becoming ineffective.

Bullwinkle eating hay

Bullwinkle eating hay

I’ve also noticed that the kids born in March are much better off than the ones born in June.  Because of pasture conditions, they seem to be out of the worm egg infested barnyard sooner, eat sooner and get on the herbal wormer sooner.  In fact, I haven’t wormed any of the three kids left on the farm that were born in March.  Myson, who was born last March, has never had a chemical wormer but has some of the reddest eye membranes on the farm.

Myson Osboer

Myson Osboer

This year, my three month weight on the March babies is at least an average of 15 – 20 pounds heavier than the June babies.  The March moms don’t get as run down either.   This is why I would love to have all my kids born in March.

My Vet’s Recommendation

The vet’s recommendation was regularly scheduled de-worming with one wormer that works.  He says he uses pancour when his kids are 4 and 8 weeks old.  He also regularly worms his adult goats.  You have to decide the best time to worm adults.  One time that would be the most beneficial is after finishing kidding.  Then moving the goats to a fresh pasture would help keep them cleaned out.  Rotating pasture is a good way to keep down the exposure to parasites.

Muffin Osboer and Kizzy Street

Muffin Osboer and Kizzy Street

Another time is in the fall when they come off pasture for the winter.  In my climate, it’s a necessity to dry lot in the winter months.  We typically don’t see worm problems this time of year because of the cold and snow, but it’s also because of the life cycle of the Haemonchus.  It has to have moisture and grass to complete its life cycle.  Dry lotting can eliminate the grass.  It does still require good maintenance, or you can end up with the coccidia because of unclean conditions.



Keeping their feed off the ground is another way to help lessen the likelihood of them ingesting worms.  I’ve never figured out how to adequately do this.

Another option he outlined was early weaning of kids (when their rumens are functioning and they are able to get their nutrition without nursing).  This would allow me to dry lot the kids and possibly use coccidia preventatives in their feed.  It also takes the stress off their mothers trying to provide food for themselves and their kids when the pasture quality isn’t as good.

Ralph (the unweanable kid) and Clover

Ralph (the unweanable kid) and Clover

He assures me that if you stick with a wormer that works and you are using routine scheduled worming to clean them all out at the most beneficial times, you will not have problems with resistance that comes with overuse.

My Vet’s Thoughts on the Famacha Charts

I did ask him about the Famacha chart and using eye color as a way to determine worming.  He said, and I quote, “I’m not a Famacha man.”  (Cue The Village People, Macho Man and everyone sing, “famacha, famacha, man; I’m not a famacha man.)  His reasoning is that it isn’t effective with kids.  Their blood volume is such that they can go from perfectly fine to dead in two days (Potsie).  Also, by the time they show a need to be wormed, they are already run down and likely to continue growing worse (Simon).  If you do regularly scheduled worming, you eliminate those problems and don’t risk getting into the cycle of re-woming every couple of weeks.

In adults, he’s still not convinced on the effectiveness of the charts, and added the time consumed by checking eyes every day makes it impractical.  It’s easy not to check every day, and by the time someone does decide to check the goat’s eyes, they’ve already seen other signs.  He also mentioned that it is subjective.  He did nod when I mentioned my Millie goat that was anemic and tested clean.  It’s not that uncommon.

Skinny Kizzy

Skinny Kizzy

My aside.  I would guess, if people used both the Famacha followed up by a fecal for confirmation of the results, we’d hear more instances of it not being accurate.  It is one tool, and it can help determine the general health of a goat.  Kizzy was pure white and skin and bones.  I did the fecal, and she had 7 eggs on the slide, which is not consistent with white eyes caused by parasites.  She gives everything to her kids, which is why I wanted to retire her this year.  I did worm her, however, because any parasite when she’s that anemic is enough to cause her system to crash.  I also weaned her kids.  If we weren’t in the midst of record heat and I could find a place to shut her in, I might have delayed worming and fed her hard to build her system up, but it was too dangerous with the heat.  That’s what I did with her last year (and then I tried retiring her from having babies).

My Advice

If you are having problems with drug resistant parasites, decide why.  Is it because you are not regularly worming all the goats and end up constantly worming one here and there and battling worms because they are quickly reinfested?  Did you buy a new animal that brought them onto your property?  If it’s from your worming practices (over-worming, using multiple wormers), stop.  Figure out a routine worming schedule and stick with it, using only one kind of wormer.

Joe and Joani

Joe and Joani

If you don’t know what wormer will work for you, it might not be a bad idea to get some help.  See if your vet can send a sample to be tested to discover what drug will work best.  Make sure you are doing fecals before and after treating.  Find one and stick with it.  Do not change between wormers.  I cannot emphasize that enough.

Have good management practices.  I think one of the best things you can do is to make sure you have good practices in nutrition (feed and mineral supplements) and hygiene (not overcrowding, cleaning out barns).  Every summer, Flower goes off grain because she doesn’t want to eat it.  I have a very large pasture and she’s content with just browsing, which means she’s not getting herbal wormer.  She’s not been wormed with a chemical wormer since she was a baby.  I can’t say whether it’s the herbal wormer that protects my adult goats or that they have good nutrition and plenty of space.



Granted, Flower’s not raising kids and it’s easier for her to stay healthy than it is for my moms, but it serves to illustrate that keeping them healthy will help them handle the parasite load they have.

Another note on herbal wormers:  not all herbal wormers are created equally, and there is very little research on their effectiveness.  I really recommend doing fecals before and after to determine their effectiveness.  When in doubt, go with the regularly scheduled worming when it will have the most impact rather than guessing with herbal wormers.

If you don’t have problems with drug resistance, but you don’t have a clear plan for parasite management, get one.

My Plan

With a huge sigh of relief, I pretty much plan on going back to what I was doing, but using the Cydectin.

  • Routine planned worming of kids at 4 and 8 weeks  (I will worm all the kids at one time, so they will actually range 4-6 weeks and then 8-10 weeks)
  • Use herbal wormer religiously with adults (and kids over 8 weeks)
  • Kidding when the pasture conditions will be most beneficial to kid and mom health
  • Maintain proper nutrition for good health
  • Keep a clean environment (clean barns out; not overgrazing pastures)
  • Use fecals to determine need for worming adults
  • Find Kizzy a chastity belt because three is way more than the zero kids I planned for her to have
Kizzy and unauthorized kids Cora, Little Bit, and Quigley

Kizzy and unauthorized kids Cora, Little Bit, and Quigley

My only hope is that my little Boer girls hadn’t been given Cydectin along with the other drugs.  As I was doing some of my most recent research, I found that the information on available wormers I’d been given for the last several years was a bit inaccurate.  There are three classes of wormers.  You have your white wormers (Pancour and Valbazen).  Ivermectin and Cydectin are actually in the same class of wormers, which makes me a bit nervous about whether or not the Cydectin will continue to be effective.

There is, however, another wormer that was widely used in the 1970s, Levamisole (Prohibit).  It became ineffective in my part of the world, and it went out of use, which is probably why nobody was talking about it.  Now, it’s proving to be effective again.  There is hope if we can get people to start using smarter worming practices.

Drug Resistant Parasites in Goats Part II

10 Sep

The Situation

Remember, I was talking about the problems I have with worms being resistant to two of the three main chemical wormers available for goats and how this situation came to exist on my farm.  If you haven’t read Part I, you can find it HERE.


Goliath (before he recovered)

Rotating Wormers

There are all kinds of theories to avoid resistance, and one I’ve known several people to practice is to rotate through the different classes/brands of wormer.  The theory is that by rotating, it will take longer to develop resistance since they will be exposed to each class of wormer less frequently.

In reality, if you kill ninety percent of the worms with a pancour wormer, you have some that have been exposed to it still living and passing eggs to the rest of the herd.  The next time you worm, you use an Ivermectin product, and now ten percent of those that survived before have now been exposed to both.  It doesn’t seem like much, but it does compound the problem.

This means it will simply make the worms resistant to all the wormers as you progress.  It might make it more difficult to know which resistant worm (or worms) is in each goat, so you end up with a game of Russian roulette, wondering if this is the wormer that will take care of the problem.

Boer/Saanen cross buck

recovered and all grown up

Sadly, this is what can also lead to that cycle of worming every two weeks when you get a goat that has gotten full of worms and run down and they continue to re-infest the goat.  Even though vets will tell you to do this and rotate wormers as the only possible way to save a goat’s life, it does exacerbate the problem of drug resistance.

More Bad Advice

No matter whom you speak to, you get the advice to worm goats.  It’s a vicious cycle.  I already wormed them, and nothing works but Cydectin, but if I use Cydectin it will be ineffective within two years (according to one ISU vet).  She suggested I  send a big conglomerate of goat feces to them, and they will send it on to Georgia, where they will actually hatch the worm eggs and do testing to see which chemical wormer will most likely be effective.  Well, that’s all well and good, but I have kids that could drop dead without any warning, and the time it takes to do that isn’t going to help.  Also, I know the wormer it will tell me to use is Cydecitn (oh no, you can’t use that).  Also, it won’t tell me which goat it won’t work on, so I’m really back to where I was before.

Goat Poop

There has to be a way to tell if a wormer is effective or not without the goat drop dead or having to have a blood transfusion.  There is.  You take a fecal sample and send it to Iowa State for a McMaster’s fecal test.  On the same day, you worm the goat.  Ten days later, you get a fecal sample from the same goat and send to Iowa State for the same test.  If 90% of the worms have been killed, then the wormer was effective.  Okay, last I knew, it was $35 for that one fecal exam, so you’re at $70 plus either postage or driving the samples to Iowa State and the wormer.  We’re at $80 or more, and that would have to be done for each kid.  That means, with the forty-two kids I started with, it would cost over $3300.  Not to mention, ten days is too long to wait if it isn’t working.  They’ll be dead.

Little Bit Osboer

Little Bit Osboer

Then mention that it’s difficult to train goats to poop on command, and you get told that you have a finger.  I’m not even going to mention how impractical and likely to cause injury that is on some smaller kids.

Complicating Matters

To make things even worse, for the first time this year, I’ve had kids that the wormer worked on, but they grew increasingly anemic and weak.  The first kid I lost was Simon.  I had wormed him, before he showed any signs, with the rest of the kids.  A couple of days later, he had diarrhea, and I did a fecal.  He had just a couple round worm eggs and a few coccidia.  By all accounts, this shouldn’t make him sick, but it did.  Keep in mind, that it requires a completely different wormer to treat coccidia.



Sadly, it was too late to help Simon, but a vitamin cocktail (B complex and A,D&E at 1cc each/20 pounds) and probiotics helped Art.  He also got IV fluids subcutaneously.  It helped but still left him dumpy.  The reason they continued to decline even though I wormed them is probably because they already had a heavy load by the time I first wormed them.

Gray Osboer

Gray Osboer

Another factor is the coccidia.  I never had coccidia in my goats until after the chemical wormers started failing on the roundworms.  Because I didn’t know about the failure or this secondary invasion, the worms reproduced freely spreading eggs all through my soil.  Coccidia are a secondary invader, taking advantage of a weak or sick animal.  The presence of just those few can be enough to cause an already fragile goat to fail.

Herbal Wormer

Then, as soon as I say, “herbal wormer,” to a vet, I can hear the eye rolls through the phone.  However, I started using the herbal wormer after I nearly lost Millie and Bam Bam because the chemical wormer only eliminates worms in one stage of the life cycle.  That means it doesn’t take long before the goat can be filled just as badly as before they were wormed.  You can end up in a cycle of worming every two weeks that still sees the animal failing and causing more problems with resistance.

herbal wormer paste

That’s what was happening with Bam Bam (see Part I), and then I started him on the herbal wormer.  He thrived from that point forward because the herbal wormer makes them an “inhospitable environment.”  The worms won’t attach to the lining of their stomach and simply pass out of their body.  You can actually see live worms in their feces if they are just getting started on the wormer.

worms on goat pellets

Sadly, the herbal wormer is not a panacea, and because nobody has done studies, you’re pretty much on your own trying to figure out the fine details of using herbal wormer.   It works very well for a nice healthy adult.  Some times to  watch a goat closely and be leery as to whether or not the herbal wormer is working:

  1. If a goat is not feeling well, it doesn’t work.
  2. I also have to watch and make sure each goat is getting their fair share.  Like chickens, they have a pecking order, and not all goats get the same amount of food.
  3. I have some moms that are so busy trying to avoid their kids that are relentless in trying to nurse that they don’t get enough to eat.
  4. They have to have a fully functioning rumen.  That means it is not effective on kids until they are about two months old.  By this time, they can already be full of worms (Potsie/Simon).

What’s a Farmgirl to Do?

Thursday, I’ll give you my best advice from a lot of reading and consulting with my vet in the final installment of worm resistant drugs.  Well, it will be the final installment until the worms change the rules on me again.

I promise no more poopy pictures for the Part III on Thursday.

Drug Resistant Parasites in Goats (Part I)

9 Sep

Anyone who has had goats know that they seem to be more susceptible to parasites than any other animal on the plant.  Add to that worms that are becoming increasingly resistant to chemical wormers, and that’s the stuff that keeps me awake at night.  Sadly, that’s true.

I shared in July that I lost a couple of kids (three total), and I sent Potsie to Iowa State for an autopsy.  When the results came back that he had “lots” of roundworm (Haemonchus) and coccidia, I was devastated.  I rushed home and gave Art, who was still not doing well but improving, a different class of wormer from what I had used on all the kids just a couple of weeks earlier.  Luckily, he is doing quite well now.

Art Osboer

Art Osboer

There are three main wormers that are used on goats for roundworms.  Your “white” wormers (like Pancour, Valbazen or Safeguard), Ivermectins, and Cydectin.  I am at a point on my farm that the only one of these chemical wormers that will do anything is Cydectin.  It’s the last line of defense (Cue scary music).

Two years ago, I told you about Pam and Stormy and their struggle with worms when the Ivermectin chemical wormer had failed them.

Stormy Sue Street

Stormy Sue Street

My first time of dealing with failure from a chemical wormer was clear back in fall, 2007, when I almost lost Millie and Bam Bam.  This was the first time I had ever wormed my herd.

Bam Bam

Bam Bam quite recovered

There’s a couple of goats that I can look back on now, and it makes me wonder if drug resistant parasites played a part in their deaths as well.  It’s hard to know what to do to keep the goats healthy because there is so much contradictory information on worming that you get from different sources.

Mabel and Flower

Mabel and Flower

Talking to different vets in the same clinic will get you different information.  Don’t even start me on all the misinformation you find on the Internet.  (I religiously avoid goat chat groups on Facebook.)

Then you deal with the ISU vets that are great in a crisis because they can give a blood transfusion and save a life.  They will however, accuse you of neglect, lie to you, do fecals you don’t give permission for because they just lied to you, be condescending, arrogant and judgmental.  They also tell you any fecal is inaccurate except theirs (including my local vet’s fecals), and I’m obviously not smart enough to tell if a goat is anemic by looking at their eyes because I don’t have a Famacha chart in my hand.  However, I’m very grateful for the lives they’ve saved.

Moose Osboer

Moose Osboer

Famacha Eye Chart

I’ll give you my thoughts on the Famacha chart here.  This chart was developed in South Africa to use the color of the goat’s eye membranes to predict worm level.  They found it effective, and the drug companies thought we should use it here in the United States to determine when to worm based on eye color.  Some people thought it should be tested in the United States to see if it was effective in the different climate.  There was one study done in the south and Barbados.  I have not been able to see the actual study, only the report that it was effective.  Now, I might be crazy, but my climate in Iowa is no more like the climate in Florida than it is to South Africa.  I wonder how it works in a temperate climate.  I also don’t know how the goats were fed–dry lot or pasture.  I really think that might have an impact as well.  I’m not sold on this as being as effective as they claim, but I’ve had vets recommend it and read enough to try it.

normal and anemic

normal and anemic

I tried to use eye color, but my experiences haven’t been very good with it.  I actually do check quite frequently, even if it isn’t every day.  Trust me, when you start to check every day, after about day three, Dolly will not let you anywhere close to her.  I can also use Dolly as an example of how it isn’t accurate (if you believe I can tell the difference without the chart in front of me, which the ISU vet doesn’t).  Dolly was pretty much completely white (and I hardly ever say that).  I got a fecal sample, and she had 35 eggs on the slide.  I wormed her with Valbazen.  I couldn’t get another sample ten days later, but two weeks later, she had 15 eggs and was still completely white.  A couple weeks later, I was happy to see she had a bit of pink in her eye membranes and figured the extra handfuls of  corn and herbal wormer was helping.  A couple days later, I got another sample and even though her eyes were still pinker, there were so many eggs I couldn’t count.  I weaned her boys and waited for my consultation with the vet (end of story later).

Dolly Ann Street "I don't want to smile for the camera."

Dolly Ann Street “I don’t want to smile for the camera.”

Millie has also twice been completely wrong.  When her girl, Bambi, was a baby, Millie was completely anemic.  The vets did a fecal that was clean.  There was no real reason for it other than CAE goats tend to be anemic, and she gives everything to her kids and gets run down.  When Miranda was little, two years later, she was pink, but had a respiratory infection (from the CAE).  The vet examined her and saw no reason to suggest worming.  The next day, she ended up with diarrhea and I took a sample to the vet’s office which showed she was full of worms.  That’s too many times being wrong to trust.  Don’t even start me on how unhelpful it is with the kids.

Millie Ann Saanen

Millie Ann Saanen

Causes of Drug Resistant Worms

How did I get to this point?  What causes the resistance to wormers?  Overuse.  It’s that simple.  Sadly, people worm goats at the drop of a hat.  Every time they worm needlessly, it exposes the worms and gives them another opportunity to become resistant.  Sadly, I swear a vet will tell you to worm every single time anything is wrong.  When Millie was anemic but had no worms, I was still told to worm her.  Honestly.  I also had a vet tell my brother-in-law to worm a goat with a swollen jaw.  Now, I know bottle jaw comes from worms, but when the goat has an open abscess, you need antibiotics, not a wormer.  There’s also that cycle of a goat that has bad worms and you end up worming every couple of weeks and then switch drugs.  The vets will tell you to do this too.

Annie Belle O'Boera

Annie Belle O’Boera

My vet shared that we didn’t have much of a problem with drug resistant worms in my area until just recently.  That’s when there was a change from primarily dairy goats to meat goats.  People brought Boer goats up from the south knowing they already had problems with drug resistance.  They mistakenly thought that our cold winters would be enough to control the situation.  Our cold winters do keep the numbers down, but it does nothing to help with drug resistance.  It simply brought that problem to Iowa.


Bambi Blackboer

So, another way you can end up having problems with drug resistant worms is buying an animal (or three adorable little does) that brings them to your property.  You’ve probably heard to isolate and worm before you integrate them with the herd, and I did that when I bought my little Boer does.  I did not do the fecal tests to confirm that the wormer had killed the parasites, and the rest is history.  This is not a problem I caused, but it will be my problem for as long as I have goats.

Tuesday, Part II:  The Bad Advice

Thursday, Part III:  My Best Advice

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