For the folks here whose dogs have been diagnosed with both Cushing's and Diabetes, here are some links which may be helpful.

Therapy of Concurrent Diabetes Mellitus and Cushing's Syndrome
Canine and Feline Endocrinology and Reproduction
Edward C. Feldman and Richard W. Nelson, 2004 rrent+Diabetes+Mellitus+and+Cushing's+Feldman&hl=e n&sa=X&ei=mbVBUe_3KrG04AP-wICYAQ&ved=0CDYQ6AEwAA#v=onepage&q=Therapy%20of%20 Concurrent%20Diabetes%20Mellitus%20and%20Cushing's %20Feldman&f=false"

Q & A: Diagnosing Cushing's Disease in Dogs with Diabetes Mellitus
Insights into Veterinary Endocrinology (January 22, 2012)
Dr. Mark E. Peterson

Link to the "Vetsulin" (Intervet) website brochure, about dogs with Diabetes:

Another part of the Intervet website, with information about managing canine diabetes:

Link to the original Pets with Diabetes website. Although it is now inactive (i.e. it has not been updated for several years) there is alot of excellent information there:

*note: the site has been offline since June 2008, but the site has been archived in two locations.

See here for the petdiabetes archived site:

Or here:

The archived petdiabetes site can also be seen here:

There is also a messageboard associated with the petdiabetes site: