Timpani did not respond to treatment, so I made the decision to have her euthanized as there was no hope for a full recovery. I had been writing about the whole experience on my blog and on Facebook, and many people had responded that they had been through the same thing and waited far too long to make that decision. We learned from Timpani’s necropsy that she did indeed have meningeal worm, and it was in her brain stem, so her condition would have simply worsened over time until she died.
Windy responded well to treatment. The day that Timpani was euthanized, Windy started walking again and even looked the vet in the eye, which was a huge improvement as I had initially thought she had gone blind when she first became ill. In fact, this part of the story has a really happy ending as Windy was pregnant. I knew she had been bred, but I thought that the sickness and all of the drugs might have caused her to abort, but as the months went on, her belly got bigger, and she developed an udder. I worried that she might have a five-legged kid or something malformed because of all the drugs she had been given early in pregnancy, but four months later, she gave birth to healthy twins. She still held her body crooked for many months and couldn’t run straight, but she eventually recovered well enough that an average person would not have known there anything wrong with her.
The coccidian protozoa can reproduce asexually in the intestines, so once a kid is infected and symptomatic, it needs to be treated. Because coccidia are often lumped into discussions with worms, some people are under the mistaken impression that dewormers will treat coccidiosis, but they do not. A five-day treatment of a sulfa drug is commonly used to treat coccidiosis in goats. Prior to the 2017 change in US law, it was fairly common for people to use a lower dose of a sulfa drug in water for two weeks as a preventative. Although you can still do that if you get a prescription from your vet, this is a bad idea. If a goat gets coccidiosis while on a low dose of a sulfa drug, then that drug won’t work to actually treat coccidiosis because the protozoa is resistant to it.
Amprolium is approved for the treatment of coccidiosis in cattle and poultry. It is not labeled or approved for use in goats, but it is used to treat coccidiosis in goats. When coccidia are exposed to the drug, they become thiamine deficient and die. Unfortunately, there have been cases of goats becoming thiamine deficient when taking more than the recommended dosage or for longer than usual times. Although it can be used as a preventative, it is not recommended because of the risk of long-term use causing a thiamine deficiency. Since the drug kills the protozoa by making them thiamine deficient, it would be counter-productive to supplement the goat with thiamine while treating. Thiamine supplements can be given after treatment has ended, but it is not usually necessary when following the recommended dosage.
Medicated milk replacer, minerals, and feed containing decoquinate or monensin are available as preventatives in goats. Oregano oil looks promising for treating poultry with coccidiosis, and there are anecdotal reports of black walnut hull powder being used in goats, but more research is needed before we can definitively say if these remedies work consistently in goats and at what dosage.
Many people are familiar with the research on grazing sericea lespedeza or eating lespedeza hay and reduction of barber pole worms, but studies with sericea lespedeza pellets with goat kids and sericea lespedeza leaf meal with lambs have shown that the need for pharmaceutical treatment of coccidiosis can be reduced considerably. In one study, oocyst counts were reduced by 96.9 percent within seven days of kids starting to consume the pellets.12
Good barn hygiene, however, should be the first line of defense against coccidia. When kids are on pasture, they are more likely to have problems with intestinal worms because grass is an important part of the life cycle of those parasites. It would be nice if you could just keep kids in the barn for a couple of months and assume you didn’t have to worry about parasites, but that’s not the case. Confined kids are much more likely to suffer from coccidiosis because of exposure to fecal pellets in barns, which contaminate bedding, hay that falls to the ground, and water buckets if a goat poops in them. Since virtually all adult goats have some level of coccidia in their intestinal tract, this is why most people who bottle feed will house kids separately from adults. However, when dam raising, the kids are getting mom’s antibodies to the coccidia through her milk. This is why we never wean doeling that we are keeping. By leaving kids with their dams and keeping the stalls clean, it’s been many years since we’ve had a case of coccidiosis in any kids other than bucklings after weaning. When kids go to a new home, it’s best if they are housed separately from adults while they recover from the stress of the move.
Controlling Internal Parasites
It takes a holistic approach to control parasites in goats. You cannot do it by simply using herbal or chemical dewormers and coccidiostats. The goal is not the elimination of parasites in a goat’s body. Parasites are a natural inhabitant of the goat’s gastrointestinal tract. Because zero parasite load is impossible, it is important that goats develop some natural resistance to worms and coccidia, and that does not happen unless there are some in the body. The key, however, is to prevent excessive parasites that affect health, growth, or production, and ultimately kills the goat. It is more effective to be proactive with your management, rather than to be reactive, trying to save ill goats with drugs.
Many new goat keepers have no problem with worms in the first couple of years because the pasture is sparsely stocked. They don’t realize that the low stocking density is the reason for the absence of problems and assume that whatever they are doing in terms of deworming (or not) is working. This explains why a deworming protocol such as pour-on chemical dewormers and some herbal preparations appears to work even though research has shown that it does not. If there is no worm problem to begin with, doing nothing may have worked just as well. As the herd grows, however, the parasite load on the pasture increases. A dead goat is often the first indication of a problem for many goat owners. It happened to me, I’ve seen it happen to other people on my internet goat forum, and it is often mentioned in scientific journal articles about goats and worms.
Dewormers
Although it appears there are about a dozen chemical dewormers on the market, all fall into one of three categories. Drugs in the same category have a similar mode of action and work to kill similar worms. When I was writing the first edition of this book five years ago, a new dewormer that was the first in a new class had been submitted to the US Food and Drug Administration (FDA) for approval, and I naively wrote that it was not expected to be on the market for a couple of years. Monepantel is still not on the market in the United States, although it was already available in Australia at the time the first edition was published. Some researchers and veterinarians do not think it will ever be approved for use here.
“White dewormers,” so called because they are most commonly sold as a white liquid or paste, are benzimidazole dewormers, which include fenbendazole and albendazole. It appears there are more dewormers than there really are because some brand-name drugs have the same one or two active ingredients. Panacur and Safe-Guard both use fenbendazole as the active ingredient. Valbazen is the trade name for albendazole. Only Safe-Guard is approved for use in goats, but other drugs are used off-label. The benzimidazole class of dewormer is the only one effective against tapeworms. While a single dose of albendazole kills tapeworms, fenbendazole must be given three days in a row to treat tapeworms. Albendazole is not recommended for use in early pregnancy, but it has been linked to a variety of problems in multiple species at different stages of gestation, so some people may choose to avoid it throughout pregnancy.
The second class is the macrocyclic lactone dewormers, which are sometimes called the clear dewormers because they are a clear liquid or gel. This includes ivermectin and moxidectin. Moxidectin is considered much stronger than ivermectin, so ivermectin is generally used first because moxidectin can still be useful in some goats when ivermectin no longer works. Although these drugs are not labe
led for use in goats, they are approved for extra-label use orally or as a pour-on. Moxidectin injectable is not supposed to be used in goats, and although ivermectin injectable is approved for extra-label use, the milk withdrawal is 40 days, making it impractical for use in milkers.
Imidazothiazole dewormers are the third class of dewormer. They are usually sold as a water-soluble powder, a bolus, a medicated feed, or a feed additive. This class includes levamisole and morantel tartrate. Morantel tartrate is the only drug in this class approved for use in goats. Levamisole is sold as a bolus or as a powder that can be mixed with water and given orally. Because levamisole has been used so rarely in goats, some people have found that it works when other dewormers are no longer effective, including Rumatel, which is in the same class. One must be very careful, however, when using levamisole because the margin of safety when dosing is not as large as with other dewormers, making it easy to overdose a goat. While most sheep dewormers are used in goats at twice the sheep dosage, levamisole is used at only 1.5 times the sheep dosage.13 Signs of toxicity include tearing of the eyes, excessive salivation, and the goat walking like it’s drunk. In most cases, the goat will recover after a few hours or days of rest.
When individual dewormers no longer work, it is possible to combine two dewormers from different classes. For example, you can give a dose of albendazole and then a dose of ivermectin immediately. (Do not mix them together.) If one drug kills only 70 percent of the worms, for example, and the other one kills 70 percent of the worms, each of those drugs will kill some of the worms that were resistant to the other dewormer, so you will wind up killing more worms than if you had used only one. In some cases, depending upon the level of resistance to the dewormers, you can kill as much as 90 to 99 percent of the worms when using two dewormers at the same time.
As of this writing, one researcher is advocating the use of dewormers from all three classes at every deworming. Although research has shown that provides the best efficacy rate in terms of killing worms, I personally won’t do that unless I have a goat that really needs it. Every time you use a dewormer, you take a step towards dewormer resistance, and if you combine all three, then you’ve just created a world with only one dewormer. If people only used dewormers when it was absolutely necessary, then dewormer resistance would never happen. But obviously lots of people are indiscriminately using dewormers, and I’m concerned that if everyone starts giving all three at once, the worms will become resistant to this combo, leaving producers with nothing to use when a goat is seriously debilitated by worms. This isn’t just theory. It actually happened a decade ago on our farm. The idea of using two or three dewormers has been around for that long, and when we started seeing dewormer resistance, we started using two dewormers. Ultimately we used all three, and within only a few months, they quit working.
Extra-label Drug Use in Goats
Because goats are a minor species in the United States, it is not profitable for drug companies to test their drugs on them to get FDA approval to have the drugs labeled for use in goats. Veterinarians and owners, however, need to be able to treat a sick animal. The Animal Medicinal Drug Use Clarification Act (AMDUCA) of 1994 created guidelines for using drugs extra-label so that drugs can be used legally in different species, even when the drug has not been FDA approved for that species. However, this does not mean that you can use whatever drug you want to use in goats.
According to AMDUCA, you can use an extra-label drug to treat your animal only after consulting with a licensed veterinarian and only if there are no FDA-approved drugs available to treat that condition. You may also use an extra-label drug when the only approved drugs don’t work. For example, this means that legally you should only use fenbendazole or morantel tartrate as dewormers because they are labeled for use in goats. However, if they no longer work, you could use a dewormer that is labeled for a different species.
To find approved dosages, as well as meat and milk withdrawal times for extra-label drugs, consult the Food Animal Residue Avoidance Databank (FARAD), farad.org, which is supported by the United States Department of Agriculture (USDA) and maintained by several universities. If you don’t see a milk or meat withdrawal time, you should not use that drug in an animal that will be used for milk or meat. Sometimes there is no recommendation because the drug has not been studied, but it may also be because the drug stays in the animal’s system for so long that it is impractical to use it, especially in dairy animals.
Dewormer Resistance
It is a well-known fact that internal parasites are the leading cause of death among goats. Unfortunately, it is a problem of our own making. You have probably heard of antibiotic-resistant superbugs, which resulted from the overuse of antibiotics. A similar phenomenon has occurred with chemical dewormers and internal parasites in livestock. Veterinary professionals thought parasites could be eradicated in livestock and began recommending routine use of chemical dewormers in healthy animals. Although this worked in the short term, the long-term consequence has been dewormer-resistant parasites.
During the 1980s and 1990s, the standard advice was to deworm livestock on a predetermined schedule in an attempt to keep internal parasite loads so low that they would never adversely affect production. When people started to see that the parasites were surviving dewormings, the advice was changed slightly to tell people to switch dewormers from one treatment to the next so that the new drug would kill the worms that weren’t killed by the previous dewormer. To reinforce this idea, one company even came out with a horse dewormer system that numbered their different dewormers so owners could use them based on which quarterly deworming they were administering. To complicate matters for the goat owner, large animal vets see plenty of horses and may focus their continuing education on the animals that make up the largest portion of their practice. This means that when it comes to goats, many vets are still repeating what they learned in vet school 15 or 20 years earlier. Depending on where a vet went to school and who taught the small-ruminant classes, even some newer vets are still practicing with old information. One researcher told me that about half of what we know about parasites has been discovered in the last 20 years, and much of that was not taught in vet school until the last five years. Many of the old recommendations were based on personal experience, opinions, and logic and subsequently have been proven to be wrong.
In the last ten years, a lot of research has been done on internal parasites, especially on barber pole worms, because of the large losses experienced by sheep and goat producers in the southeastern United States. A great deal of research in this area, however, has been done in Australia, New Zealand, and South Africa. One study after another clearly shows that dewormer resistance is a real problem. Because there are only three categories of dewormers, it does not take long for a resistance problem to develop when they are used frequently. Research shows that if parasites are resistant to one drug in a class, only a more potent member of that class will work.14
In addition to being used for internal parasites, ivermectin and moxydectin are sometimes used as a pour-on for external parasites, such as lice and mites. Unfortunately, the internal parasites are being exposed to the dewormer when it is used as pour-on, and it only kills about 50 percent of the internal parasites when used in that manner, which means it leads to problems with resistance faster.
Before you start thinking about how you can smuggle in Monepantel, the new dewormer that you can’t get here, you should know it did not turn out to be as useful as most had hoped. Within only a couple of years of introducing it in Australia, parasites were already showing resistance to it on some farms and ranches because of blanket deworming of every goat instead of selective deworming and maintaining refugia.
When talking about resistance, it is important to understand that we are not usually saying that the drug kills zero percent. Ideally, a dewormer will kill as close to 100 percent as possible. But the more you use a dewormer, the fewer worms it will kill because the population of resistant worm
s is surviving and reproducing. Depending on how sick a goat has become from a heavy load of parasites, a reduction of 70 or 80 percent may not be enough to save it from dying. It is also possible that a severely debilitated goat will die even if all of the worms are killed. The sooner you stop overusing chemical dewormers when parasite resistance is evident, the better your chances of reversing the problem will be.
Common Deworming Practices
Using dewormers selectively means that you deworm only when an animal has a level of worms that is causing it to be anemic, not grow normally, not produce milk as expected, or otherwise show signs of illness. You do not deworm a doe simply because she has kidded or because other goats in the herd have a high level of parasites. These two practices will lead to rapid dewormer resistance problems. Now, you’re probably wondering why so many people do prophylactic deworming and why many vets recommend it. It is what was taught old school before much research had been done on parasites. Without looking at long-term research, prophylactic deworming seems to work.
Myth #1: If you deworm all the does after kidding, they have lower parasite loads, lose less weight, and produce more milk. Why wouldn’t everyone want to do this? Because in the long term, this is part of a losing strategy. It is unlikely that all of the does needed deworming, and using a dewormer when it isn’t needed means you have just taken one more step towards dewormer resistance and the day when a dewormer will be needed and it no longer works. By deworming all of the does, you are selectively breeding worms for dewormer resistance. Also, by deworming routinely at kidding, you lose the opportunity to select breeding stock based on parasite resistance.
Raising Goats Naturally Page 12