When planning a lecture on poisonous plants for an equine medicine class that I am a teaching assistant for, I remembered a case that I once saw. It was October, and the weather was chilly. The leaves had been falling for some time, and the colors were beautiful. I was working the evening shift at a rural clinic when we got an emergency call. The owner was worried about something strange that occurred after she brought her horse in from the pasture. The horse urinated in its stall, but its urine looked like “red wine” according to the owner. The horse appeared normal otherwise. Suspecting a common pasture toxin that occurs in the fall, the owner called us. The infamous toxin comes from red maple (Acer rubrum) leaves that the horse eats.
When the horse got to the clinic, it urinated again. Sure enough, the urine was not normal. It was a dark red-to-brown color. Still, the horse appeared otherwise normal. Its heart rate was not elevated, nor was its respiratory rate. Upon further inspection, we did notice that its mucous membranes (its gums) were slightly brown/yellow, further confirming our suspicion of red maple toxicity. With clinical signs like these, the veterinarians and I were surprised that the horse was standing and did not seem to be in any distress.
The owners expressed financial concerns, so we took the most frugal approach to figuring out what we should do. We took a blood sample and ran a fast test that would help us determine the best course of action. A packed cell volume (PCV) can be completed in less than 5 minutes and can tell you the status of an animal’s red blood cells in relation to its plasma. We commonly use it to see how dehydrated an animal is, but in this case, we wanted to see how the horse’s red blood cells were handling the red maple toxin, which is thought to be gallic acid found in the wilted leaves of the tree. When eaten, it is converted to a powerful oxidizing chemical via the horse’s gut bacteria. This oxidant can damage red blood cells.
Generally, a normal PCV for horses is 32 to 52%. This horse’s PCV was 15%, which further confirmed our hypothesis. Further, it indicated that the horse was so affected by the toxin that this was a lost cause. Given the horse’s status, it was a prime candidate for a blood transfusion. We talked with the client about the treatment options. After some time to think, the clients said they could not afford to treat the horse. This horse was not a working animal, it was a pasture pet that they acquired and did not use for any recreation. The horse was older, and it was not insured. They simply could not find the means to treat this horse, especially with a treatment that may not be effective.
This was a reminder to me that this is the nature of our practice. We deal with people that have insured animals, and we deal with people that cannot afford care for their animals. This is our reality, and our job is to serve all of our clients and patients to the best of our abilities.