A couple weeks back, this column featured information about certain seasonal plants that can be toxic to pets. A regular, local reader with some remarkable credentials wrote in to offer her knowledge on how to fine tune the piece.
To begin, know that I really appreciate any criticism here or anywhere, so long it is constructive and accurate. All such things done in good faith benefit us both, columnist and the audience of readers. To this I tip my hat to Monique Slipher, a professional arborist and horticulturist for some 40 years.
Slipher is also curator of the Charles Gardner Shaw Mycological Herbarium in Washington State University’s Department of Plant Pathology. She oversees a vault of more than 76,000 fungal specimens kept for a variety of important reasons in health, agriculture, education and our environment.
Lest ye think I have slipped a cog and this pet column is now something else, you’re mistaken. You see, fungi are in some respects more like animals than they are plants. As a group, the fungi include molds, mushrooms and yeasts. To receive an email of respectful criticism like that from Slipher is an honor.
In fact, animal and disease specialists monitor the fungi as they are one of the only such organisms that can and do evolve to produce disease in mammals. Plant fungi can infect humans and animals by inhalation, ingestion or direct contact with certain plant materials. Most, but not all, such infections are rare. They most likely infect those with weakened or incomplete immune systems.
It also bears repeating here that those of us older than 65 have a naturally weakened immune system. In 2023, a man in India was the first human to contract an infection from silver leaf fungus that normally only infects trees. His symptoms included difficulty swallowing, hoarseness, cough, lack of appetite, fatigue and recurrent throat inflammation. It is believed he was immunocompromised.
Emerging infectious diseases in animals that are caused by fungi that you may have heard or read about include white-nose syndrome in bats, and Amphibian chytridiomycosis, known as Bd, a waterborne fungal infection that has caused the decline or extinction of more than 200 species of frogs and other amphibians. And there are more.
So why do these diseases emerge? The best hypotheses now are continued climate change and habitat loss. Trust the disease investigators: It is important to monitor for any jumps of such fungal diseases to humans or food animals.
Slipher offered a correction to my description of yew trees being toxic in ungulates. “Pacific Yew, Taxus brevifolia, is our only Northwest native yew species, and not one typically used for landscaping since it’s very slow-growing and scraggly in form,” she wrote. “It’s present in the nearby Idaho forests, e.g. around Laird Park.”
She’s of course correct. She went on to write, “When elk push down in winter into populated areas with landscaping, they will encounter several non-native horticultural species and cultivars of Yew: English Yew (T. baccata) or Japanese Yew (T. cuspidata) or the common hybrid of those 2 (T. x media), and — mostly — the cultivars of all those. Again I’m not sure about for wildlife, but for humans it’s specifically the red berries (or more correctly arils) of any of those that are toxic.”
That is great to know, as I admit my plant ignorance. I sent her back a news release from the Idaho Department of Fish and Wildlife detailing previous cases of elk deaths attributed to eating yew. My guess would be that eating any cultivars of yew could be toxic if enough is eaten.
As for people, don’t eat the berries.
Powell, of Pullman, retired as public information officer for Washington State University’s College of Veterinary Medicine in Pullman. This column reflects his thoughts and no longer represents WSU. He may be contacted at charliepowell74@gmail.com.
