Just saw this texas breeder who claims most of the maltese he breeds will be 3lbs to 4 lbs at maturity.
But i also heard that maltese not within the standard size 4lbs-7lbs will have health problems. So is there anybody who can give me some advice?
Yes…they will have numerous health issues beyond reasons. The dogs you are describing are dogs called “teacups”
They are inbreed runts, the breeder takes the small runts ( most of which are already prone to health issues are breed them to produce even “smaller dogs”.
A healthy Maltese should weight 4-6 pounds and these dogs are not healthy, a real breeder wouldn't breed them to be this small. Dogs that are bred to be this small have numerous health issues because their skeletal structure is fragile, they often suffer from bone and muscle issues, as well as neurological and behavioral issues from being inbreed.
Its best to stay away from any dog that is called a “teacup” they don't exist, this is just a cutsey name BYBers use to scam people into buying their BYBred mutant mutts.