3CsMommy, almost right. The strep is not zoonotic, it is Streptococcus equi subtype zooepidemicus. Zoonotic means that the disease passes from animals to humans or humans to animals, which is not the case here. The abscesses are generally under the chin or on the front of the throat. They can also occur on the inside of the hind legs, but those are more rare. I have seen animals with just runny sticky eyes, just an abscess, or both.
Quarantine is good, but may not completely solve the problem. I brought the causative animal into my herd in January and did not see this disease until April. Also the animals that I brought into my herd never got sick, their cage mates that had never left my ranch were the ones that developed abscesses first. Every other animal that has caught this has had direct contact, either caged with or caged next to, an animal that has gotten sick. The animals are contagious before they start showing any symptoms.
Again, I have not lost any animals to this. It is ugly and a pain, but it hasn't been deadly for me.
The rest is spot on.
I will try to get pictures of some of the abscesses later this week. Those that have large, well furred animals will have the hardest time spotting abscesses before they are rather large as they tend to be hidden with how the animals usually sit. Breeding collars can also hide or irritate the developing abscesses. Generally by the time the abscesses are large enough to rupture on their own they are about the size of a large shooter marble or slightly smaller than a ping pong ball so they are harder to miss. Hope this help clarify things.