February 9, 2012

Streptococcus myositis – the consequence

If you remember the horse that I wrote about last month – starting here – Streptococcus Myositis – a vaccine reaction

Well the story does not have a happy ending, which is why it has taken awhile to update all of you. I let the owners grieve for their loss and then I asked them today if I could post the update. Not only was the owner willing to let me post the update but I also have pictures so you can see what devastation this vaccine reaction can have.

Here is Tango in Tennessee where the owners first saw him and they tried him out on trail. Notice even in the shade you can see his good body weight and dappling. He looks overall like a healthy horse. He was given the vaccine earlier in the week as well as his Coggins test in anticipation of him being sold to the new owners and brought up to Illinois.
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Four weeks later and a few days before he was euthanized (put down). He is a good 300 lbs lighter.
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Tango tried hard and was at one point on the road to recovery. His blood values were increasing, meaning the anemia seemed to be improving. Unfortunately the treatment for this disease is to lower the immune system with corticosteroids, so the body stops attacking itself. There are two risks in this treatment – 1.) laminitis (founder) just from the corticosteriod use and 2.) another infection taking hold due to the lowered immune system. Even though Tango was on antibiotics, his lungs filled with fluid, possibly a consequence of the steroid use or possibly another infection causing pleuropneumonia. His temperature never remained stable and his blood values were sinking again. When he finally stopped eating and looked depressed again, enough was enough and the decision was made to put Tango down. Even though his new family had him just over a month and the majority of the time he was sick, he will be sorely missed.

His owners have this to say – “We do not want his death to be in vain; Please let this story of his death be a reminder of what powerful effects vaccines have on the immune system. Horse owners need to be conscious of what they are giving their horse. Hopefully this will save at least one other horse.”

Streptococcus myositis – A Strangles vaccine reaction, part 3

Here we are back at the story of our little horse that was vigorous and strong only 3 weeks ago and now looks like it has lost 300 lbs, has a severe anemia in which the owner has given one blood transfusion, and has a fever that is on again and off again and has spiked now to 109.5! That is not a typo – the horse’s temperature was at 109.5 degrees during the day when the outside temp was near 90. Bathing the horse and putting it under fans and giving some Banamine reduced the fever, but that was very scary!

So what happened next. Well my friend who owns this horse being a small animal veterinarain asked me a simple question, can the horse still have immune mediated anemia and have a negative Coombs test. Well I’ll be – a question I did not know the answer to – LOL. So he asked a clinical pathologist, a doctor who specializes in reading blood results and other laboratory tests. He’s the doctor we get on the phone with when all the blood results look screwy and we have no idea what way the blood is directing us. He is the guy that makes sense of it all. So the answer came as a startling yes. The horse can have immune mediated disease and still have a negative Coombs test. OK well then what now?

The clinical pathologist then asked the most important question of them all, the one that solved this mystery. When was the horse last vaccinated and with what? Did it have a strangles vaccine recently? YES, it did have a strangles vaccine at the same time the Coggins test was pulled. Well looking at the results of the blood tests and the signs and symptoms of your horse, he believes the horse has vaccine induced immune mediated anemia. Otherwise known as Streptococcus myositis caused by a reaction to the Strangles vaccine. It is much more prevalent in Quarter Horses but can happen in any breed. The theory is if the horse already has a high titer to Strangles and the vaccine is given anyway it sends the immune system into overdrive and causes purpura hemorrhagica and results in a immune mediated myositis (muscle inflammation and deterioration).

So that is what I was seeing not a trauma induced bloddy nose but rather purpura hemorrhagica. Also the horse was tying up but the cause was not because of being cast but rather an immune mediated myositis. Here is a picture of what I saw – The picture is from the Merck Veterinary Manual Website -
purpura.jpg
Notice the nose looking like it was hit with something.

The horse seems to be doing better, however, we are not out of the woods quite yet. He still needs some TLC to get better and as I said before the Rapid Response is helping this horse tremendously. I will keep you posted on the events with this horse, but hopefully this story will help you realize as to how important it is to be informed on your decisions to vaccinate with what and when. It may be more important to not vaccinate for certain diseases as is my opinion with strangles. If you are not in a high risk environment (meaning stabled with a bunch of 2 year old show horses that come and go every weekend) then it is more important to pass on this vaccine. Your horse’s life may depend on not being vaccinated!