Tom Sandoval and his model girlfriend Victoria Lee Robinson are pitching in to help animals impacted by the L.A. wildfires ... the couple has taken on an adorable foster dog who they say is preparing them to be future parents!

TMZ interviewed the "Vanderpump Rules" alum and his better half about their work with the L.A. dog shelters that are trying to facilitate adoptions so they can make way for displaced pooches affected by the devastating fires.

Tom and Victoria -- a lifelong animal lover -- tell us their cute 8-week-old canine named Milo might be a handful ... but he's worth the trouble because he's brought them closer together.

The dynamic duo also agree that caring for Milo is great practice for them because they "both want to be parents." Sounds like their relationship is pretty serious and there might be some little Sandovals running around soon.

As for who the dog likes better, Milo seems to be more Team Victoria than Team Tom ... at least according to Victoria who says the pup prefers to cuddle with her. Sorry Sandoval.

Here's the back story ... Victoria --- a Maxim cover model -- and Tom began fostering Milo while volunteering with Laura Labelle and her L.A.-based Labelle Foundation ... a nonprofit organization that's been a main player in finding homes for canines as shelters are inundated with pups due to the wildfires.

Labelle tells TMZ ... the couple is playing an essential part in raising awareness about their efforts and has even helped some dogs get adopted. Paw-some job!