If you are interested in adopting a service dog for a vet, we suggest you begin your search at Assistance Dogs International, the certification board that the VA works with. Visit their site here:
http://www.assistancedogsinternational.org/members/programs-search/
If you have a dog to recommend as a service dog, please visit the Assistance Dogs International search by state page to view the list of organizations you can contact:
http://www.assistancedogsinternational.org/location/north-america-adina/