Azalea – The toxins in azalea plants can be very severe and potentially cause drooling, diarrhea, vomiting, central nervous system weakening and depression, and in some cases possibly coma or death.
Castor Bean – Poisoning as a result of this plant can cause abdominal pain, drooling, diarrhea, vomiting increased thirst, loss of appetite and weakness. More serious cases could also lead to dehydration, tremors, seizures, twitching muscles, coma and possibly death.
Cyclamen – The most poisonous portion of this plant is located in the root. Ingestion of the plant can cause severe vomiting and gastrointestinal irritation. In some cases death has been reported as a result.
Kalanchoe – Ingestion of this plant can cause gastrointestinal irritation and cardiac rhythm and rate problems.
Lilies – Plants of the lily variety are very poisonous to cats as well as dogs. Even very small amounts of this plant could cause serious kidney damage.
Marijuana – Animals who attempt to snack on this plant can suffer serious consequences such as diarrhea, vomiting, increased heart rate, drooling, in-coordination, and even possibly seizures and coma. You really shouldn’t have this plant around anyway. ;)
Oleander – All portions of this plant are poisonous and can cause gastrointestinal irritation, hypothermia, heart problems and possibly death.
Sago Palm – While the seeds and nuts of this plant are most poisonous, the entire plant is toxic. Animals ingesting parts of this plant may suffer from diarrhea, vomiting, depression, seizures and liver failure.
Tulips – The toxic portion of this plant is the actual bulb, which can cause drooling, central nervous system depression, gastrointestinal irritation, cardiac issues and convulsions.
Yew – Poisoning as a result of the yew plant can affect the nervous system and cause in-coordination, trembling and breathing difficulties. It may also result in gastrointestinal irritation, cardiac failure and could possibly lead to death.
And on a related note…
Coco bean mulch is also toxic to dogs. I don’t know why more people do not know about it or make the connection between coco & chocolate, but the manufacturers need to do a better job of informing customers of the dangers.
Snopes gives the following information:
Cocoa Mulch, which is sold by Home Depot, Foreman’s Garden Supply and other Garden supply stores, contains a lethal ingredient called ‘ Theobromine’. It is lethal to dogs and cats, but it really attracts them because it smells like chocolate.
Theobromine is in all chocolate, especially dark or baker’s chocolate which is toxic to dogs. Cocoa bean shells contain potentially toxic quantities of theobromine, a xanthine compound similar in effects to caffeine and theophylline.