It could mean a lot of things. A Chihuahua’s legs are tiny and delicate as well as cute. So never ignore a limping Chi and take your beloved companion to the dreaded vet as soon as possible.
One possibility is a common hereditary problem in small dogs. It’s called “Luxation of the Patella” and means the dislocation of the kneecap. When the attached ligaments of your dog’s leg get stretched over time the patella can easily pop in and out of place. This has happened to me. If I bend my back leg a certain way or my daddy picks me up and holds me, my kneecap sometimes pops out of it’s proper place.
Stretching my leg carefully and massaging it puts my little kneecap back in place. Unfortunately this can’t go on indefinitely since it could worsen over time and cause other leg problems as I get older. So surgery is required. And can you believe both back legs have this issue?! Talk about bad genes. I blame my biological parents.
In general it’s also best to keep your Chihuahua lean and healthy by feeding a good balanced diet and not overfeeding. It’s never good for tiny legs to hold up lots of fat. And now I am about to go on my daily two mile hike with daddy.