Rhubarb, a common garden plant, is widely recognized for its edible stalks, which are frequently used in various culinary applications like pies and desserts. Its vibrant, tart stems make it a popular perennial in many home gardens. However, a question often arises concerning the broader parts of this plant: do animals consume rhubarb leaves, and if so, are these leaves safe for them?
Rhubarb Leaf Toxicity
The leaves of the rhubarb plant are generally considered unsafe for consumption due to their high concentration of oxalic acid. This naturally occurring compound is present in various plants, including spinach and broccoli, but its levels are significantly elevated in rhubarb leaves. For instance, rhubarb leaves can contain approximately 0.5 to 1.0 grams of oxalic acid per 100 grams of leaves, a concentration much higher than in the edible stalks.
When ingested, oxalic acid can bind with calcium in the body, forming insoluble calcium oxalate crystals. This process can lead to a reduction in available calcium, a condition known as hypocalcemia, and the accumulation of these crystals can damage organs, particularly the kidneys. Symptoms of oxalic acid poisoning can range from mild gastrointestinal upset, such as nausea, vomiting, and diarrhea, to more severe issues like kidney stones, kidney failure, and muscle tremors. Cooking does not break down oxalic acid, meaning processing the leaves does not eliminate their toxic properties.
Animals and Rhubarb Leaves
Most animals, both domestic and wild, instinctively avoid consuming rhubarb leaves because of their inherent toxicity. Deer, for example, typically steer clear of rhubarb plants due to the high oxalic acid content in the leaves, which acts as a natural deterrent. This makes rhubarb a deer-resistant plant, often chosen by gardeners in areas with significant deer populations. Similarly, livestock are generally not fed rhubarb leaves due to the known toxic effects.
Despite this general avoidance, there are rare instances where animals might nibble on rhubarb leaves. Wild animals like bears, raccoons, skunks, squirrels, and even some birds may occasionally consume them, particularly in early spring when other food sources are scarce. However, the damage caused by these instances is usually minimal.
For domestic pets, the risk of ingestion is more concerning due to their proximity to gardens and potential curiosity. Dogs and cats, for instance, are susceptible to oxalic acid poisoning if they consume rhubarb leaves. If a dog ingests rhubarb leaves, symptoms can include mouth pain, excessive drooling, vomiting, diarrhea, lethargy, and in severe cases, muscle tremors or kidney failure. For cats, similar signs such as increased salivation, vomiting, diarrhea, and potential kidney damage from crystal formation are observed. Rabbits are also highly vulnerable, with rhubarb leaves potentially causing kidney damage, digestive issues, and even fatalities in large quantities.
Safeguarding Rhubarb Plants
Given the potential for accidental ingestion, especially by curious pets, protective measures around rhubarb plants are advisable. A simple and effective method involves physical barriers, such as low fencing, which can deter animals from accessing the leaves. Strategic placement of rhubarb plants in areas less frequented by pets can also reduce the risk of exposure. Gardeners might consider locating them in raised beds or containers that are less accessible to ground-dwelling animals.
Educating pet owners about the dangers of rhubarb leaves is another important preventative step. Prompt action is crucial if ingestion is suspected; contacting a veterinarian or animal poison control immediately can lead to better outcomes. Proactive measures ensure the safety of garden inhabitants and pets, allowing for the enjoyment of rhubarb’s edible stalks.