My parents have a 12 year old golden retreiver who has had many health issues. She has come close to dying on a couple of different occasions. There was a wierd problem that she was having...she was bleeding from her nose. The vet figured out after alot of research that she was probably having this reaction because the neighbors next door had very potent weed killer on their lawn, and my parents dog had a bad habbit of chewing on the grass by the fence. After the vet informed my parents of this, they kept their dog away from the fence, and the problem quickly got better. They love this vet clinic.