The following articles are used with the written permission of the author, Gillian Willis, pharmacist and toxicologist.Note: Each article is separate, but they have been combined on one page.
Trees
Birch
Birch belongs to the Betula species. The LEAVES and BARK contain salicylates as well as some principles that have hemolytic properties (destroys red blood cells). The low concentration of salicylates in the birch BARK is unlikely to cause toxicity in avians.
Salicylates can be given to avians as an analgesic. The WOOD of birch (Betula sp) is used for such things as ice cream and Popsicle sticks as well as for toys.
Removing the bark would eliminate any exposure to salicylates. Birch branches should be considered safe for natural wood perches.
The seeds inside the cones are a special treat and are safe for the birds to eat.
Black Walnut
Black walnut (Juglans nigra) contains juglone. There have been no reports of toxicity in HUMANS from ingestion of parts of this tree. Ingestion of parts of the black walnut has caused toxicity in HORSES.
Juglone has produced sedative effects when administered intravenously to experimental animals.
It is unlikely that ingestion of small amounts of the wood/bark of Black Walnut would cause toxicity in birds. The ripe nuts may be given to birds to eat. With walnuts, always crack open to check to ensure that they have not gone mouldy. Mouldy walnuts has caused serious toxicity in dogs and are potentially toxic to birds.
Maple Trees
Red maple (Acer rubrum) is also known as maple, soft maple, scarlet maple, curled maple and swamp maple.
Maple bark itself, is probably not toxic. However, there is a fungus that can grow on the bark, inhalation of which, can cause maple bark disease ( a form of allergic alveolitis). Maple wood would be safe to use for natural wood perches once the bark has been removed.
Maple seeds and the sugar-rich young leaves are considered edible EXCEPT to horses.
Wilted and dry, not FRESH, maple leaves produce an oxidant which has caused hemolytic anemia, renal failure, pulmonary edema and death in horses.
Oak and Acorns
The buds, young sprouts and raw acorns (fruit) of the oak (Quercus sp.) contain tannins, gallic acid and pyrogallol. Poisoning by these toxins in animals can cause gastroenteritis, kidney and liver damage. Symptoms of poisoning may be delayed for several days following the ingestion.
Oak poisoning is more common in cattle and less so in sheep and horses. The toxicity of the oak varies with the growing season, climatic and geographic factors.
In humans, ingestion of ripe acorns in young children seldom causes problems apart from the occasional gastrointestinal upset. It appears that raw acorns are potentially more toxic.
Acorns are still a cause of serious poisoning in livestock. I was unable to locate reports of toxicity in the avian species. Since there is the potential for causing toxicity, and because the nutritional value is questionable, it is probably best to avoid giving acorns to birds to eat.
I realize that oak branches have been used as perches and have not caused problems. There is the potential for toxicity so are probably best avoided.
Red Cedar
The question of red cedar (Juniperus virginia) bedding, branches etc is always controversial. Red cedar contains a volatile oil that can cause dermatitis and gastrointestinal tract irritation.
There is a report that cedarwood shavings (Juniper species) cause a high mortality rate in rat pups. Poisonings in cattle have also been reported but are rare. Pregnant ewes fed Juniper caused abortions and necrotic rumenitis. (Ref. Humphreys DJ. Veterinary Toxicology).
I have a report on file of a Yorkshire terrier ( wt. 3 - 4 lbs) who was found chewing on a cedar branch. One hour later he began to shake and looked really ill (? nausea). The dog did well with supportive care.
There is a risk for toxicity for all animal species so red cedar is best avoided.
Gillian Willis
Vancouver, BC
Copyright © Gillian A.Willis
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