Please visit these sites.
This is one of those things that you must be informed about because this knowledge may save your dog's life.
globalspan.net
Mar Vista animal medical center
Dog Owners Guide
Elektrik Borzoi
Great Dane Links
dachshund.org magazine
You know your own dog the best and you know when things aren't quite right.
If you notice any of the signs in your dog, call your vet or take him to an emergency clinic as soon as possible.