Men and women returning from Afghanistan and Iraq are facing new physical challenges because of the injuries they received.

Some will need prosthetics, while others will need the help of a service dog.

Two organizations in Denver, Freedom Service Dogs and Canine Partners of the Rockies train dogs to assist people who are mobility impaired.

Forty-two years ago, Artie Guerrero was shot in Vietnam. He now lives in Golden with his wife and service dog Sierra. Guerrero is wheelchair bound.

Guerrero got Sierra in October 2008 from Freedom Service Dogs, a non-profit organization that rescues shelter dogs and trains them to assist people with disabilities. Guerrero said Sierra helps him with daily tasks such as picking up his keys or credit card when he drops them.

“What I couldn't do without some obstacle, she does with ease,” said Guerrero.

Guerrero said the dogs are perfect for veterans who are injured -- they can be adapted to a veterans needs.

“The dog can be trained for a full service companion, it can be trained for balance if you have a limb that puts you off balance,” said Guerrero.

On Sunday, a half a dozen dogs and their trainers met at Washington Park in Denver for their bi-monthly training session. The dogs are part of Canine Partners of the Rockies.

“It is the difference between dependence and independence,” said Linda Port, training and programming director for Canine Partners of the Rockies.

Port said its dogs are trained for anyone who is mobility impaired, not just veterans.

Volunteers train the puppies for 18-20 months. The dogs then graduate on to intense professional training for six months before they are given to a person in need.

It's bittersweet when it's over for the trainers, but they said it’s rewarding knowing they are making a difference.

“If we can get a dog to do those simple tasks for someone we can greatly increase what they can achieve during the day and the quality of life, the independence that they can have with one of our service dogs,” said Joyce Thielen, a first-time puppy trainer.

Canine Partners of the Rockies has two litters of puppies it is expecting in late June or early July needs volunteer puppy raisers.

The average cost to train a dog is $1,500 for the 18-20 month period.

Freedom Service Dogs www.freedomservicedogs.org Canine Partners of the Rockies www.caninepartnersoftherockies.org.