- Written by: Sharalee Worms
- Written by: Sharalee Worms
IMM
We have had IMM listed in our list of Genetic Issues under "Other Genetic Issues" for a while now but thought since the recent release of a readily available "For Purchase" test has brought a lot more notice to this disease we would publish an article on it.
Have you ever had a horse that lost a drastic amount of weight in a very short time? Was it just after you vaccinated it or it came down with Strangles? Good chance the horse had a mutated gene which caused that issue.
IMM stands for Immune-mediated myositis - it is a dominant disease and you can have a genetic test done on your horse to see if it carries a copy of the mutated gene. Even though it is dominant (meaning it only needs one copy to show symptoms) many horses that have this mutation never show any signs. That is because it seems to need a trigger. Right now known triggers are Strangles and certain vaccines.
An IMM horse having an attack will rapidly lose muscle along the backbone - to the pont where you can see the skeleton. This happens within 2 days to 2 weeks, It is treatable with Corticosteroids - and should be treated ASAP. Once treated, horses can usually come back to their original weight within a few months.
So far, the IMM MYH1-E321G variant has only been found in Quarter Horses, but it seem to be fairly widespread in the cutting and reining lines.
IF you own a horse that fits the description above (rapid muscle loss after an infection or vaccination, especially over the back and hind end muscles) seek help from a veterinarian.
BRIDGEquine would also be interested in your horses pedigree so please contact us. If you have questions you can email us at foals@manitobahorse.com - Just put IMM somewhere in the Subject line.
- Written by: Sharalee Worms
MFM P8 Genetic Testing is Available
MFM is Myofibrillar Myopathy - it is dominant disease
MFM symptoms include exercise intolerance, tying up, pain, stiffness and tremors, heavy sweating, and in severe cases an inability to stand. Another symptom is very dark coffee colored urine. All of these signs often come after exercise and/or high stress.
MFM can be seen clearly on a muscle biopsy.
Horses that carry one copy of either P3, P4 or P8 have a predisposition to develop MFM (also diagnosed as PSSM2). Horses with two copies of the variant (P3/P3 or P4/P4 or P8/P8) have stronger symptoms and the symptoms show up when the horses are younger.
Treatment includes a high portein diet and a specific exercise plan. For P8 high doses of Vitamin E are producing very good results.
P3, P4 and P8 are used to signify MFM at this time.*
*Researchers at EquiSeq have identified semidominant alleles of two genes that causes MFM in Thoroughbreds and related breeds. The results are not yet published in a peer-reviewed academic journal. Prior to publication, the variants have been termed P3, P4 & P8.
You can get your horse tested for P8 at Equiseq.com
- Written by: Sharalee Worms
Welcome to the heart of PSSM
The links on this page will take you to Real Life Stories of people who have dealt with genetic issues in their horses. Some of them have had good success, and bluntly some of them have not. This section of the site is dedicated to giving horse owners a voice to share their experiences with their horse.
One thing is clear.
All genetic issues affect all individual horses in different ways. Our hope with sharing these stories is to give hope to some while also giving a strong message that is just not worth it to breed these issues forward.
PSSM1 Stories
PSSM2 Stories
IMM Stories
HYPP Stories
HERDA Stories
GBED Stories
MH Stories
Combination of Genetic Issues Stories
If the links above are not clickable it means we don;t have info loaded in those categories yet.
If you would like to have your story shared please email foals@manitobahorse.com with My Story in the Subject line.
- Written by: Sharalee Worms
With our new marking system we will showcase a different feature each month.
For the month of August I have chosen Midnight
Midnight is a foundation Quarter Horse who has been tossed around as a source for both PSSM1 and PSSM2. The people responsible for making the PSSM1 test put out a mysterious paper linking a horse to PSSM2 with the initials PM - they also had a pedigree without horses names on it but which showed offspring. When that paper first came out I spent a lot of time attempting to trace that horse -- oddly even though it was a needle in a haystack I managed to find that Midnight fit the pedigree very well and his sire is PM - Peter McCue. So is Midnight a source for PSSM2? Who knows? But for fun this month every pedigree you search will have a DARK BLUE Mark for every horse in that pedigree that goes back to Midnght. You will find a lot of horses go back to Midnight. It is very interesting to see and I hope you like this feature. The Feature Mark will not appear in the legend at the bottom of the Pedigree screen - this is the only place the mark is identified.
Go ahead - take this feature for a spin members - search your horse and see how often Midnight appears. You can click each one with a dark blue mark and follow it back until you hit Midnight to see how he fits into your pedigree.
Great Example if you don't know a horse to start with? Try my stallion Dulys Razz - he goes back to Midnight with every horse in his pedigree.
Have Fun with it! If you think this is a fun feature - like this article with our new like buttons.
Is there a horse you would like to see featured? Message me or email me and I'll see if I can make it happen.