Here is the reason a misdiagnosis might happen...look at the similarities in the eggs. Sue explains the differences in the post:
Sue Reith.
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!
Sue Reith.
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!
Sue Reith
Carmelita Toggs
Bainbridge Island WA
Sue Reith.
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!
Sue Reith.
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!
Sue Reith
Carmelita Toggs
Bainbridge Island WA