The black willow tree (Salix nigra) is common in the northeastern United States. It is the most useful of willows for wood production. It is not considered a toxic plant for dogs, but it can cause reactions if the wood is chewed in large quantities. The willow may be home to many bird and rodent species. It is a pioneer plant used in reclamation of disturbed areas and stream banks.
Willow tree bark is a source of salicylates, an herbal component similar to aspirin. This may cause a reaction if a dog chews on twigs of a willow. Since the black willow attracts many species of mammals and rodents, it is attractive to exploring dogs. Willows are prone to limb damage from weather, so there is likely to be an abundance of tree debris for dogs to pick up and carry by mouth.
Animals that are prey for dogs, including rabbits, moles and mice, will make nests in willow trees and feed on tree parts. White-tail deer and beaver also nibble on willow trees. Many insects and bees eat the nectar of the willow. Dogs that consume these animals may also be exposed to willow that the prey has eaten. Dogs that react to bee stings should be kept away from willow trees.
Flea beetles are attracted to willow trees. These beetles have strong hind legs when mature and jump like fleas. They are shiny, dark-colored bugs and should not be mistaken for the usual fleas attracted to dogs. If the willow has holes and dark spots under the leaves, this is a sign of infestation. The tree can be treated with an insecticide when dogs and other pets are kept away from the site.
The willow bark and leaves have been used historically in herbal remedies for pain and arthritis. The bark was boiled and used as a purgative by pioneers and early settlers. The black willow reduced to charcoal was used as a gunpowder. The British homeopathic physician Dr. Edward Bach suggested the willow as an antidote to resentment and self-pity in his original 38 Bach flower essences and remedies.
Black willow trees both attract and may cause harm to pets. There is risk of exposure to salicylates for dogs who may chew on the bark or debris from the tree. Dogs chasing prey or chewing twigs or objects need extra supervision if black willow wood is present.