Introduction
It’s finally a beautiful May Friday afternoon in South Carolina and you are looking forward to a relaxing weekend with your family after a long week at the clinic. At 4:30 you get a call from a distraught woman, not a regular client, who runs a relatively small but successful Thoroughbred breeding and training farm on the outskirts of town. One of her best mares, due to foal in 1 month, is dead and several other horses appear sick!
“My day has gone from bad to worse,” she says, “I had no help with this after my best handler called in sick with the flu this morning…”
You jump at the opportunity to do some detective work on an interesting case, (and hope you may just gain a new client out of it?). Once at the farm, you begin putting together a history:
“"Trouble" was not herself two days ago, was depressed, wouldn’t eat, and was breathing really fast yesterday morning when our regular vet came out. Now he's gone on a fishing trip and I can't get a hold of him!”
The report from the other vet describes clinical signs including depression, edema of the face, lips, and neck. HR= 55bpm. No rectal temp or respiratory rate recorded. Dx= allergic reaction. Tx= antihistamines, flunixin and antibiotics.
What other questions do you ask the client to continue developing the history? The client’s horses spend most of their time on good pasture, an acceptable deworming schedule is in place, and according to her records, her horses have received all of their necessary vaccinations, including rabies, influenza, tetanus, Western and Eastern equine encephalitis. Horses are supplemented with what appears to be good quality hay and an oat-based concentrated feed. Management on this farm appears to be very good.
The client thought Trouble was getting better, as she appeared more alert yesterday morning, but by this morning she refused to rise, progressed to lateral recumbency, and now she’s dead. Several other horses in the barn also appear ill .
“Please help me before I lose another one!” she gasps. What do you do now? (Don’t tell her this is your first year out of school)
Before you start your necropsy on the mare, who is lying in a stall with a frothy exudate coming from her nose, you head to the barn to check things out. If this is a highly infectious agent, it would be a real mistake to bring whatever it is into the barn to the other horses. Your mind starts racing through the beginnings of a long list of rule outs for severe respiratory disease…
On the way to the barn you notice several cats milling around. The owner mentions that one of them came from her sister who had been living in Australia. Your conversation is cut short when you reach the barn.
You examine a second mare who is noticeably depressed and exhibiting dyspnea, tachypnea, tachycardia, has a rectal temperature of 105.8º F., has injected mucous membranes with a cyanotic border and nasal serosanguinous discharge. A couple of other horses also appear to be having trouble breathing, show areas of patchy sweating and one appears slightly off balance or ataxic, and has icteric sclera.
Roll the mouse over the picture to see the name of the clinic sign exhibited.
Other mares and foals in pasture appear normal, healthy. None of the other horses have been coughing recently and there have been no abortions this year.
WHAT ARE YOUR INITIAL GENERAL RULE OUTS FOR SEVERE RESPIRATORY DISEASE?
