I have a new mare... Have had her a week. On day 3 she developed a yellow snotty nose with thick yellow snot.?

It could be strangled. That's what came to mind first.

Check your horse for lumps, especially around the head, throat, ears and neck and groin...in fact just call a vet asap. Strangles is not to be messed with.

Sounds more like Shipping Fever to me. Here's a link: http://www.horseandhound.co.uk/horse-care/horse-ca...

When horses are shipped somewhere, they don't drink as much water as they should and they get dehydrated. This messes with the defense mechanisms of the lungs, leaving them prone to pneumonia and other infections. The symptoms are exactly as you describe - fever, lots of snot, painful difficult breathing.

Regardless of the actual issue, your vet has prescribed things that should help. Keep him apprised of her condition, as he may add stronger ones or change them up or do more tests.

eta: Strangles is an infection of the lymph nodes in the jaw and neck area; Shipping Fever is an infection of the lungs and pleural cavity.

I think your mare probably has strangles, Lexi. The first symptom of strangles is a high fever, followed by a thick, foul smelling, greenish or yellowish discharge from one or both nostrils. This is accompanied by listlessness, lack of appetite, and breathing difficulties. Some horses exhibit mild colic signs too, while others will develop diarrhea. But the worst symptom of this disease is the swollen, infected lymph nodes under the horse's jaw and around the face. It's these which give this disease its name, because they make it difficult if not impossible for the horse to swallow and eat. The animal's throat becomes very inflamed and sore, and the abscesses can really cause problems.

Strangles is a bacterial infection caused by the bug called Streptococcus Equi. This bug is a cousin of the same bacteria which causes strep throat in people, and it's possible for people to get strep throat by coming into contact with a horse that has strangles. There was a case in the Dallas-Ft.Worth area a few years ago in which a woman actually DIED from a strep infection which she acquired after treating her horse, who was sick with strangles. The woman had been healthy before her horse got sick and she started treating him. So while it's not common, it's also not unheard of for this to happen.

Most cases of strangles generally resolve on their own in about two to three weeks, provided that they are uncomplicated. Sometimes, though, horses will develop a secondary infection which is known as "bastard" strangles. In these cases, the bacteria attack the horse's vital organs, including the lungs, heart, brain, and large and small intestine. The disease can produce abscesses in these organs which are often fatal to the horse.

There is a lot of debate among veterinarians as to whether or not antibiotics should be used in the treatment of strangles. Some of the old time vets that I've worked with in the past never used antibiotics at all, they preferred to let the disease run its course. The thinking behind that was that this would give the horse the greatest level of immunity after he or she recovered. But there are other vets I've known who do just the opposite and insist that infected horses be started on antibiotics right away. It varies depending on the person and where one is, I think. In your case, I think that the antibiotic probably hasn't had enough of a chance to reach full efficacy yet, which is why you haven't seen any improvement in your mare's condition. It takes time for the levels of medication in the blood and tissues to become high enough that they actually start to be effective and do their job- it's not an instant process. And while you may not have noticed any swelling under your mare's jaw as yet, eventually that will appear, if this is a case of strangles. When it does, you need to have your vet come and treat the abscesses. He or she may need to lance and drain them in order to get them to heal. And yes, the mare needs to stay on antibiotics for at least 2 weeks, and 3 would be even better. She also needs to have good shelter and protection from the winter weather.

Strangles is HIGHLY CONTAGIOUS. The fact that your mare came to you from a sale barn is what makes me think this is strangles and not heaves or asthma. Sales barns, lesson barns, and public riding facilities are notorious places where horses can pick up infections like this one. That's usually why it's recommended that horses which will be shown a lot or exposed to a lot of strange animals be vaccinated for this disease.