I can remember those bright red fruits that would shine above me during the summer as my friends and I ran around the woods in rural Maine playing capture the flag. Upon asking my Mom what the pretty plant was, she was quick to inform me that it was “Choke cherry” and that it would make me very sick. Just like all other times in my life, my Mom was so wise on that day. Choke cherry (Prunus virginiana) is a plant that contains the deadly chemical cyanide. I used to assume that eating the plant would give me a belly ache. I never tested my assumption. As it turns out, that was a very good choice!
The plant keeps cyanide concentrated in its leaves and seeds, which just happens to be the equivalent of a dessert for some of the animals in our lives. In particular, animals that have new access to this plant are at risk. Perhaps they escaped the pasture due to a down fence. Perhaps a landscaper decided to throw all the brush that was bush hogged into the pasture for the animals to eat. These events all fit into one of the main tenets of poisonous plant consumption: the introduction of a new food. This will usually entice animals so much that they cannot help themselves but eat the plant, whether or not it even tastes good or has higher nutritional benefit. Goats are curious, and a new pasture or any area beyond the fence is basically an open smorgasbord for them. The bushes are cupboards and the leaves are cookies.
One main clinical sign that my professor always reminded us of is the bright red blood that is seen on necropsy of a dead animal that ingested cyanide-containing plants. This is because of the chemical changes that occur in the red blood cells when cyanide interacts with it. As vets, we hope to reach the animal before this point, but that is not always the case. Necropsy skills may not be fun, but they are an essential part of a large animal vet’s career. Many of the poisonous plants that we deal with do leave noticeable signs in an animal’s body, so we must keep them in mind.