I live in the upper Midwest, and anaplasmosis can be very serious here. I am currently treating a horse who has required IV fluids and has developed purpura on his nose, mouth, and legs as a complication. He is quite sick. I would encourage people not to wait to see the vet if anaplasmosis is suspected. This horse was perfectly fine at 8 am, sick at 4pm and at the vet by 6 pm all on the same day.
[QUOTE=S1969;8830013]
Do you know for sure that they had anaplasmosis? Or just dealing with a fever of unknown origin?
In my area, a high fever of unknown origin is suspected to be a tickborne illness, but obviously there are other reasons a horse could run a fever - other viruses, illnesses, etc. I’ve had horses run mild fevers and recover with no treatment. But the sudden onset of high fevers? I’ve brought the vet in and treated - and even with treatment (antibiotics and banamine) they were more than 48 hours.[/QUOTE]
We actually weren’t hearing it called “anaplasmosis” back when we had our major run of it, which went from 1994 until about 2002 and then mysteriously dropped off. At one point in the 90’s our local vets asked to take blood from all the horses on our farm to send to Yale, where they were doing investigational work trying to figure out the incidence over the Northeast area to try and nail down a pattern. My town came up the epicenter, oh joy! These days, however, we rarely see it; the last I had was about 7 years ago now.
It was first called “Ehrlichia,” then “Ehrlichiosis Equi” and acted the same as what you’re describing–high, spiking fever moving very fast, off their feed, reluctance to move, once in a great while one would also stock up in all 4 legs. Never saw the yellow jaundice symptoms. Main point of concern was to keep the fever below the threshold of laminitis risk. The disease was common. I’ve been told the name has now been changed to anaplasmosis.
We really didn’t get very excited about it back then–owners OR the vets. Whatever we had, it seemed to be kind of self-limiting. It’s possible it was a different tick-borne bug, possible also that anaplasmosis proper is another, more virulent form with regional variations.
Ghazzu, can you speak to this?
The etiologic agent causing Anaplasmosis is a bacterium known as Anaplasma phagocytophilum. It used to be known as Ehrlichia phagocytophila and Ehrlichia equi. (When my first horse had it, it was still known as E. equi.) All the same bacteria, just renamed due to further genetic testing and reclassification.
Same thing happened with Potomac Horse Fever, used to be Ehrlichia risticii, now reclassified as Neorickettsia risticii.
[QUOTE=Lady Eboshi;8830213]
We actually weren’t hearing it called “anaplasmosis” back when we had our major run of it, which went from 1994 until about 2002 and then mysteriously dropped off. At one point in the 90’s our local vets asked to take blood from all the horses on our farm to send to Yale, where they were doing investigational work trying to figure out the incidence over the Northeast area to try and nail down a pattern. My town came up the epicenter, oh joy! These days, however, we rarely see it; the last I had was about 7 years ago now.
It was first called “Ehrlichia,” then “Ehrlichiosis Equi” and acted the same as what you’re describing–high, spiking fever moving very fast, off their feed, reluctance to move, once in a great while one would also stock up in all 4 legs. Never saw the yellow jaundice symptoms. Main point of concern was to keep the fever below the threshold of laminitis risk. The disease was common. I’ve been told the name has now been changed to anaplasmosis.
We really didn’t get very excited about it back then–owners OR the vets. Whatever we had, it seemed to be kind of self-limiting. It’s possible it was a different tick-borne bug, possible also that anaplasmosis proper is another, more virulent form with regional variations.
Ghazzu, can you speak to this?[/QUOTE]
A friend of mine was involved in that research!
My experience is very much the same as yours. With 20-25 horses, we average 1/year - high fever, inappetance, lethargy, +/- limb edema, +/- thrombocytopenia. Banamine is the primary drug and managing the fever is key, but I always give a week’s worth of Doxy as well.
[QUOTE=Dutchmare433;8830240]
The etiologic agent causing Anaplasmosis is a bacterium known as Anaplasma phagocytophilum. It used to be known as Ehrlichia phagocytophila and Ehrlichia equi. (When my first horse had it, it was still known as E. equi.) All the same bacteria, just renamed due to further genetic testing and reclassification.
Same thing happened with Potomac Horse Fever, used to be Ehrlichia risticii, now reclassified as Neorickettsia risticii.[/QUOTE]
Would you know how Rocky Mtn Spotted Fever fits into this classification?. I dont think horses can get it but dogs and humans sure can. I was told it was renamed and lumped under the anaplasmosis name.
For the scientifically inclined, here is decent review with a pretty exhaustive list of references on the subject.
[QUOTE=Lady Eboshi;8830213]
We actually weren’t hearing it called “anaplasmosis” back when we had our major run of it, which went from 1994 until about 2002 and then mysteriously dropped off. At one point in the 90’s our local vets asked to take blood from all the horses on our farm to send to Yale, where they were doing investigational work trying to figure out the incidence over the Northeast area to try and nail down a pattern. My town came up the epicenter, oh joy! These days, however, we rarely see it; the last I had was about 7 years ago now.
It was first called “Ehrlichia,” then “Ehrlichiosis Equi” and acted the same as what you’re describing–high, spiking fever moving very fast, off their feed, reluctance to move, once in a great while one would also stock up in all 4 legs. Never saw the yellow jaundice symptoms. Main point of concern was to keep the fever below the threshold of laminitis risk. The disease was common. I’ve been told the name has now been changed to anaplasmosis.
We really didn’t get very excited about it back then–owners OR the vets. Whatever we had, it seemed to be kind of self-limiting. It’s possible it was a different tick-borne bug, possible also that anaplasmosis proper is another, more virulent form with regional variations.
Ghazzu, can you speak to this?[/QUOTE]
The cases I’ve seen were as described above, but I and other local colleagues tend to treat with doxycycline (and NSAIDs for fever) rather than risk letting the horse go south. (Arrhythmias, vasculitis, and petichial hemorrhage make me nervous.)
So I can’t speak to it’s being self-limiting, though the literature says it is.
[QUOTE=pezk;8830436]
Would you know how Rocky Mtn Spotted Fever fits into this classification?. I dont think horses can get it but dogs and humans sure can. I was told it was renamed and lumped under the anaplasmosis name.[/QUOTE]
RMSF is still Rickettsia rickettsii as far as I know. Horses in some areas show up seropositive for the organism, indicating exposure, but there is little information on whether it causes clinical signs in equids.
Much of the work was in the context of determining the prevalence of the organism in a given area (lots of central and S. American studies) in order to figure the human risk of contracting the disease.
[QUOTE=pezk;8830436]
Would you know how Rocky Mtn Spotted Fever fits into this classification?. I dont think horses can get it but dogs and humans sure can. I was told it was renamed and lumped under the anaplasmosis name.[/QUOTE]
As far as I know, RMSF is still caused by Rickettsia rickettsii. It’s in the same order as Anaplasma spp. but different families, so not all that closely related Here’s a link to the whole renaming business of the families/tribes associated with Anaplasmosis, PHF, Ehrlichiosis etc:
http://ijs.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-51-6-2145
Basically, they did gene sequencing and found out that a bunch of the organisms that were in different genera all belonged in the genus Anaplasma.
(This reclassification happens a lot as DNA tech gets more and more advanced. One of the food borne pathogens I used to work with was renamed in the middle of our study.)
ETA: Posted at same time as Ghazzu.
I still miss the days when Fusobacterium necrophorum was Spherophorous necrophorus.
It was so mellifluous…
(It is the bug that causes thrush.)
[QUOTE=Ghazzu;8831500]
I still miss the days when Fusobacterium necrophorum was Spherophorous necrophorus.
It was so mellifluous…
(It is the bug that causes thrush.)[/QUOTE]
$10 dollar word! Only a scientist would use it to describe a bacteria’s name. 
Spherophorous necrophorus. was before my time unfortunately, it is a fun one. Fusobacterium necrophorum is all I’ve known it as. I enjoy Pseudomonas aeruginosa, in vitro it’s fun colors and decent smelling. In vivo, it’s horrid, though.
ETA: This is really devolving into major nerd talk, sorry!
[QUOTE=JB;8829903]
I’m not sure how the use of antibiotics would negate any immunity? The animal is still developing antibodies to the disease.
[/QUOTE]
I was puzzled by this as well.
[QUOTE=Winding Down;8836126]
I was puzzled by this as well.[/QUOTE]
I have seen no evidence that it is the case.
[QUOTE=Ghazzu;8831500]
I still miss the days when Fusobacterium necrophorum was Spherophorous necrophorus. [/QUOTE]
Having taken 3(!) years of Latin waaay back in high school, I find the change in declension ending interesting. More nerd talk, please! 
