Here is what the Merck Veterinary Manual has to say.
Stay tuned while I piece together our continuing drama that started in February 2010 with a visit to North Carolina to meet Cash cowboy, A 3 year old kid safe super quiet Tennessee Walker, who arrived in Maine 6 weeks later so sick and emaciated that the vet left us that first night with little hope that he would still be alive in 48 hours. Worst of all was that the suspected culprit that night was EHV 1 . Poor Cowboy was so ill he could not pass even the simplest of the round of neurological tests the Vet put him through.
He came with a health certificate (while on the phone with the vet later I noticed it was date 4 weeks before transport). I was appalled that they put a saddle on that spine. How does a horse loose 100 pounds in 6 weeks? It was shocking. Cash Cowboy stepped off the trailer from North Carolina to Maine weighing ~660 pounds, standing 15 hands tall, with a fever of 104 and barely able to walk. He was still eating though and drinking--but not nearly as much as he started doing once he had a dose or two of Phenylbutazone (bute) in him. Besides the fever and strong neurological failings he had no other real clinical signs of illness, one moderately swollen lymph node under his chin. Everything pointed to EHV-1. We were devastated--we were in shock. For 24 hours we carried the burden of a very real possibility of loosing not only the new boy but our beloved Lucy and Spot within the next week. Cindy and I held each other in tears but quickly resolved not to give up before we'd even begun. The vet said that horses with neurological EHV-1 do not improve. They continue on a fast spiral from this sick to dead within 24 hours.
First thing the following day we out in the paddock putting a bit brighter eyed 3 year old through another round of the tests: if we cross his legs in front putting the left hoof on the ground on the right side of the right front hoof will he still just leave it there for 20 seconds? No not even for 2 seconds. The back legs? Set that left hoof back where it goes in less than 2 seconds again. We looked at each other beaming with hope. We put him through the walking with his tail being pulled one way then the other. we even asked him turn sharply on the steep sloop of the driveway. SO much more stable than yesterday. I was teary eyed again but because of the relief as the best news possible settled on me. we walked him slurping up his warm mash of beet pulp, senior feed, hay pellets and blood builder supplement knowing that Cowboy was going live and recover from whatever it was that was making him so sick.
It took a week or so for the test results to trickle in. Negative for EHV-1, negative for EPM, encephalitis, Lyme, rocky mountain spotted fever, and even rabies was ruled out even though we were told by the Heaven's Gate Farm in NC that they didn't vaccinate for rabies in that state (they said other goofy things too like TWH have to be kept thin or they loose their gate. No one I've talked to since has ever heard that--and at 200 pounds heavier than he was when he arrived--Cowboy could trot to save his life--those goofy legs of his cannot move in that fashion). Back to the story: We continued to monitor his fever and administer the SMZs and bute twice daily. We knew he had some sort of infection somewhere from the blood analysis. It wasn't until the week after the doses of SMZs ended that we discovered where.
About 4 days after the Antibiotics ended the lymph nodes under Cowboys jaw began to grow and become increasing tender. Now the vet strongly suspected Strangles. We began hot packing with Epsom salts and three days later the fist of three abscess drain openings appeared.
This is what the second opening looked like on the second day. It would completely open up in the next couple of days and the third would appear beside it. You can see in the top photo a small healing opening below and to the left where the first small one drained.
Swabb samples where taken and the results came back Positive for Streptococcus Equi. We had kept Cowboy segregated from the other horses and now we knew we were looking at another 4 weeks of keeping them all separated and handling all buckets grooming tools manure forks individually, washing boots between visits, always feeding and caring for non sick horses first. It also meant canceling feed deliveries ferrier visits etc. and having to tell all the horsey friends to stay away!
It was interesting the different responses we got from folks. Some were very much afraid of the infection, while others said things like,"strangles is everywhere, healthy horses don't get it, your being too overly cautious." we decided to ere on the side of caution. It was not fun dealing with this nasty mess, it was expensive, and the worry over whether the others would get was tiring in itself.
During this time we had gone out and found 2nd crop hay for our patient to consume at will 24 / 7, and the mixture of beet pulp, senior feed, hay pellets given three times daily was incrementally increased according to a schedule laid out by our Vet at Maine equine Associates, until Cowboy was eating 10 cups of Blue seals vintage senior, 16 cups of Forage extender, and 4 cups of beet pulp divided into three meals and well soaked every day.
As of august 06 Cash Cowboy weighs in at ~875 and still gaining slowly. He grazes on grass all night, he eats free choice fresh first crop local hay during the day. And he still gets a one quart scoop of molasses free beet pulp crumbles from Poulin Grain and a scoop of Pormax high fat pelleted feed each day. We have been riding him and hope that he will muscle up some pretty soon.
And I will be adding pictures as I get them taken.