Cryptorchidism is a condition where one or both testicles fail to descend into the scrotum. It is a problem not uncommon to Maltese. Considered by most to be an inherited condition, there is some controversy as to whether it is a sex-linked trait or polygenic (from many genes) in nature.
Literature says the testicles should be “down” by 8 weeks of age, but in Maltese and other toy breeds, it can be a little later, particularly in the tiny ones. Sometimes a testicle will even be retractile, that is, it can be down one day and then retract back up the next (also known as a “yo-yo” testicle). Sometimes this will continue until as late as 9 months of age. Until the testicle stays down for good, the dog should not be shown as stress can cause the testicle to retract and the judge will be forced to excuse the dog.
It is a different scenario for a puppy with a testicle that is never felt in the scrotum. If it is not down by 3-4 months of age, it is unlikely that it will ever do so. Interestingly enough, it is usually the right testicle that fails to descend as it has to travel further to reach the scrotum and the cord is too short.
These puppies should be placed in a pet home with a contract that they must be neutered. A retained testicle can become cancerous years down the road, so should be removed. A cryptorchid Maltese should never be used for breeding.
The nice thing is that by neutering a cryptorchid Maltese, the problem is 100 percent eliminated and the dog will live a full, normal life.