Worming : Liver Fluke vs Haemonchus contortus + pictures of eggs
Here is the reason a misdiagnosis might happen...look at the similarities in the eggs. Sue explains the differences in the post:
I'm really pleased that you're taking on this important management issue! I thought I'd better send along these 2 comparative photos (taken from the pics you just received) because the most critical problem goat owners are running into all over the country these days is that their local vets don't recognized the difference between the
#1) FAsciola Hepatica eggs (those of the lethal Liver fluke that requires the use of Ivomec Plus at the rate of regular doses given in 3 doses with 10 days between to eradicate them entirely, thus save the goat's life)
and #2, Haemonchus contortus, a common stomachworm that's often mistakenly ID'd on slides by vets, because they resemble each other so much... The end result of that mis-dentification is that the victim goat doesn't then get the needed treatment from Ivomec Plus, thus continues to deteriorate until liver damage is irreversible...
So when you look at these two slides (below) please study them carefully... It took me a long time when I first discovered the difference myself, so it "ain't easy", trust me! (VBG)
The Haemonchus contortus, whether you're viewing a larger one or a smaller one under the slide, has pretty much the shape of a 'football field, curving equally on both sides,
Whereas the Fasciola Heptica eggs (the ones from the very lethal Liver fluke), when you study them carefully, will appear, not like the football field of the Haemonchus contortus, but instead they'll have one of the 'football field' sides somewhat flatter than the other football field side... They lack that perfect football field oval appearance. I find this even more obvious when you can find several eggs in a group under the slide, where it's pretty obvious that each of them has one side of the oval less rounded than the other. This focus on that small detail is absolutely critical to your goats getting the proper treatment as opposed to being provided with the wrong wormer, leaving you as the caregiver wondering why, despite repeated wormings, the animals will continue to deteriorate.
I run into this all the time! And invariable it's the result of the owner's frustration because his or her vet has erroneously mis-ID'd the eggs as the relatively harmless Haemonchus contortus.
If I can be of further help, please feel free to get back to me... And I'm especially curious to learn what you actually DO find on the slides when you do the exams! :-)
A goat owner writes:
>>I just finished reading your story regarding Fasciola and Haemonchus eggs being confused leading to an over diagnosis of Haemonchus contortus. I would like to ask you if you don't mind. I'm curious as too how you've managed to identify the fluke eggs when they don't float? I could understand your concept if the procedures were the same for both worms but how is it that Haemonchus and Fasciola are being mis-interpreted when different techniques must be used to find them? I'm just curious...I'm not doubting what you are telling me. I'm just learning so would truly appreciate any input.<<
Funny, I just had a bit of a 'set to' with a university professor on the East Coast (a parasitology prof, for gosh' sakes!) who challenged me with the same words! Just below here is my response to him...
It's true that Fascioloides magna Liver fluke eggs do not show up on a fecal slide, since White tailed deer, not goats and sheep, are their normal hosts. But unfortunately sheep and goats are environmentally exposed to them as well, so while these worms don't mature normally in sheep and goats, thus do not produce eggs that will appear in fecal matter, the immature 'juvenile' forms do indeed wander around aimlessly in them anyway, busily destroying their liver tissue. (Georgi's Parasitology, 7th Ed., P115.)
OTOH, the Fasciola hepatica Liver fluke eggs, which ARE specific to goats and sheep (as opposed to White tailed deer) can easily be seen on a fecal slide. (Pics follow below)
While there are actually 13 reference ID pics found in the group of common internal parasites of goats and sheep, I've narrowed down the options in the pics below to just those of the Fasciola hepatica (Liver fluke) eggs and the Haemonchus contortus ('Barberpole worm') eggs, in order to make the comparison analysis of the two just a tad easier...There's actually a difference in egg size between the Haemonchus contortus and the Fasciola hepatica (that of the Fasciola hepatica being somewhat larger than that of the Haemonchus contortus), but I've yet to see both species on the slide together, ever, thus that difference in size can't really be used as a 'tie breaker' when trying to tell which egg is from what worm.
Unfortunately, due to what they've been taught in university parasitology classes such as the one taught by the vet I had the recent 'set to' with, most vets don't even give Liver fluke the slightest consideration, the result being that when the worm's erroneously ID'd as Haemonchus contortus and treated with plain Ivomec, its lack of effectiveness seems to indicate 'resistance', when in fact it's actually a mis-identification, leading to use of the wrong wormer... But when the right wormer is used, there's an immediate, clear, and highly successful response!
Re: Liver Fluke vs Haemonchus contortus + pictures of eggs + LF Article
(an often-misidentified worm that's lethal if not treated for properly)
by Sue Reith.
Liver fluke damage is generally rather slow in appearing in mature goats... In a reasonably healthy goat, it can take years of gradual decline before the owner is even aware that Liver fluke is present. Symptoms are some, if not always all, of the following: Gradual increase in unthriftiness (dry coat, guard hairs sticking up, ribbiness, pale eye membranes (indicating anemia caused by the worm's activity), a swelling under the jaw (that has erroneously been considered among the veterinary community to be symptomatic of resistance to treatment for haemonchus contortus), and, eventually, a possibly sub-normal temp (less than 102 degrees), a distended belly (symptomatic of last-stage liver disease), and fecal pellets that are almost black in color and shriveled up with pointy ends on them.
Often the victim goat is one that has been wormed routinely, and yet still continues its gradual decline. The problem is that there's only one wormer on the market that will wipe out Liver fluke properly, Ivomec PLUS, (the PLUS part being clorsulon, specifically for eradication of Liver fluke) and many owners don't even know this wormer exists! Sadly, even when the owner finally learns about it and starts treatment, by that time there has often already been too much damage to the goat's liver for it to be saved even after proper worming.
BTW: While Liver fluke damage is often found in otherwise well-managed mature goats that despite good care continue to decline in appearance, in my experience this sudden appearance of anemia and weakness with either normal, or subnormal, temp (and sometimes swelling under the jaw as well) is not at all unusual to discover in young ruminants within the first few months of life as well. At that age it commonly shows up when they're heavily exposed to it in pastures containing wet areas, before their immune systems can get up and going to protect them. In fact, it's not uncommon for these young victims to die so fast they hardly have time to be sick.¹ This is especially true if there are any clostridial (Entero) organisms present in them, since they multiply and secrete their toxins fast in the already damaged, poorly oxygenated liver tissue .¹
I'm not one to quit without at least doing my best to save the goat...So if a goat of mine were affected with Liver Fluke I'd start it immediately on Ivomec Plus, using the appropriate worming approach as follows: All wormer packages note on the packaging that the product kills off ONLY the adult stages. So in order to get the worm load in the host down to a low enough level so that the immune system can take over and keep the problem under control, you need to worm 3X, with 10 days between wormings. The first dose will wipe out the adults already in there, the second dose will wipe out the larvae as they become adults (but before they can start laying eggs of their own), and the third dose kills off those eggs that were already in there when you started the worming, after they've passed thru the larval stage, when they, too, have become adults.. That leaves just a very low level of the parasites still in the host, the ones that from sheer timing
(good luck?) missed being wiped out by the worming onslaught... And that's just enough for the immune system to keep under control from then on. Having begun the repair process by giving the first dose of Ivomec Plus, the next step would be to immediatelystart it on subcutaneous injections of Ferrodex 200 (each 1 ml dose of which delivers 200 mg of elemental iron), to restorethe liver's red cells, the loss of which was the cause ofthe anemia and the blackened, shriveled, pointy-ended fecal pellets.And at this very critical time, as adjunct (supportive) therapy, I'd give it subcutaneous doses daily of 'Fortified' B-complex' (a combination of B vitamins needed for proper body function that has everything but B-12), essential because every time the patient urinates, it's losing all of those vitamins that are needed to maintenance of its body functions, and BoSe (to support his stressed immune system so that the goat can help itself to get well from
inside, while I work on it from the outside), and Banamine (to reduce the goat's pain and cut the inflammation caused by the worm damage) which, once given, will encourage the goat to want to eat once again! And last but not least, I'd give the goat a preventative doe of C&D antitoxin (to prevent entero from taking this opportunity to sneak in and finish the poor victim off because while it's down its stomach is not digesting food and moving it out of its body as it should.)
Liver fluke is found in most of the US, but it's especially common in the Southern states due to the lack of good frosts to wipe out eggs and larvae in winter. We see it often up here in the Northern states as well, but because we have colder winters, the numbers, fortunately, are somewhat lower. However during the rainy season, no matter what part of the country the goat lives in, the Liver Fluke problem becomes particularly pervasive each year!
Today, by far the most difficult problem that we as owners face with Liver fluke treatment/control is that the veterinary community in general isn't even aware that it's there. As a result, they're unable to recommend proper treatment for it. This is because the egg of the Liver fluke (Fasciola hepatica)² looks so similar to that of the Barberpole worm (Haemonchus contortus)² that when it shows up on the slide in the Vet's office it's routinely misidentified to BE that of the Haemonchus contortus (or perhaps by some general term like strongyles, stomach worms, et al).
Until just a few years ago the veterinarian, seeing what was thought to be Haemonchus contortus eggs on the slide, would recommend Ivomec to the owner as the wormer of choice to eradicate it. And rightly so, because the moment Ivomec appeared on the scene back in the early 1980's, it was recognized as the most effective general wormer to show up ever! And frankly it remains, in my view, still the best and most efficacious general wormer on the market today.
And largely because the real Haemonchus contortus has always responded very well to Ivomec, veterinarians, misidentifying Liver fluke eggs as those of Haemonchus contortus, quite logically continued recommending Ivomec for treatment. When the Liver fluke failed to respond to the Ivomec treatment, unfortunately the loss of the animal in question was assumed to be a sign of the Haemonchus contortus having developed 'resistance' to the Ivomec! This notion has now become so pervasive that the veterinary community in general believes these days that the worms affecting livestock have developed a resistance to Ivomec, the result being a recommendation to their clients that they (1) increase the doses, and (2) turn to other wormers. Neither approach has even slowed down the deaths being caused, in fact, by Liver fluke. Since neither of those suggestions are working, the most recent approach has been to set up Famacha classes to
instruct owners and veterinarians alike in how to check the eyelids of the downed animals to see if they're anemic. If the animals have pale eyelids, indicating they're anemic, owners are sometimes advised to destroy the victim, fearing that if it lives, the 'resistance to wormers' will spread even further.
Sadly, neither plain Ivomec, nor Panacur, nor any of the other general wormers on the market today, are effective against Liver fluke. The fact is, this parasite can ONLY be eradicated efficiently by using a product called Ivomec Plus . It's not the Ivomec itself, but the PLUS part of the combined wormer, which is actually 'clorsulon' , that effectively wipes out Liver fluke. And (very critically) since it only kills the ADULT of the species, clorsulon (just as all wormers) has to be used at regular doses, 3 X in a row, 10 days apart, to kill it off completely. ¹
And it will no doubt be of particular interest for those owners who are worried about using milk from does being treated with Ivomec Plus that the Pharmaceutical companies have now run the required tests on those two products that officially clears them for use in lactating ruminants!
So in my view, these days (particularly if the reader is having a hard time controlling internal parasites in his/her animals) Ivomec Plus (instead of plain Ivomec) should ALWAYS be used for general worming, 'just in case'! Just like regular Ivomec, it can be given orally although it's actually an injectable. But since right now Ivomec itself is less readily being used by people (most of whom have never even heard of Liver fluke, and many of whom have their vets ID their goats' fecal samples as well) Ivomec Plus, while its importance is gradually growing among goat owners, may not yet be available in your local feed store... However it is readily available in livestock catalogs, and online as well, at about the same price as Ivomec.
¹ Georgi's Parasitology for Veterinarians, Dwight Bowman, 7th Ed. P116.