Can I Raise dogs Adoptability?

[LittleLostJ]

You know how some dogs have two stars or three stars, etc.? I have noticed that sometimes a dog will have two stars and then suddenly be up at three stars, but I'm not sure what causes that. I take them out to play and that raises happiness, but not really adoptability. I tried to give one a vaccine to raise adoptability but it didn't really do anything. Is there something in particular I should do to raise adoptability? Or is it just random?

[Purple]

If you give them all vaccines it raises adaptability by one star if I remember correctly. You can also get stars back by washing and feeding dogs (although you probably already know that)

Some dogs are just less adoptable then others though, puppies are usually higher-ranked.

I also think you might be able to increase the adaptability of dogs if you manage to get rid of a bad trait, you can eventually do that using the computer by scheduling an event that removes random bad traits from dogs.