Each Lhasa Apso puppy should come with a warning label, "Attention: This puppy will undergo a coat change. Be prepared!" The alternative, of course, is for Lhasa breeders to inform their puppies' new owners about the grooming required to see a puppy through his coat change without having to resort to clipping him down.
The owner of a Lhasa puppy should be prepared for the puppy's coat change anywhere between the ages of 9 to 14 months. Since individuals differ, the time frame may also vary somewhat: some Lhasas may begin as early as 6 months, while others may hold off until 16 months. One thing you can be sure of, unless your Lhasa puppy has a really sparse coat, the coat change WILL happen.
What's so scary and all important about watching for the coat change? It has to do with matting and grooming.
Remember, a Lhasa's coat does not shed as most other breeds' coats do. What happens during the coat change is that the softer puppy coat is being replaced by the harsher-textured adult coat. As the adult coat comes in, the puppy coat "dies" and needs to be brushed out or it will tangle and mat terribly. At this time, your puppy may need daily grooming to remove the soft, "dead" puppy coat. You will be surprised at how much loose coat can be brushed out during coat change time. You may remark that the pile of hair on the floor by the grooming table would easily fully coat another dog! And you may wonder if your little Lhasa will have any coat left by the time you've finished brushing him! Don't worry, if all you are getting out is dead, loose hair, there's no problem.
While grooming difficulties may vary, depending on the amount and texture of your Lhasa puppy's coat, keep in mind that the coat change is a natural part of a Lhasa's development, and when it is over, your Lhasa's softer puppy coat should have given way to the harder-textured adult coat, which is usually a lot easier to take care of. Now that's something to look forward to!
Knowing what's going to happen is only part of "being prepared." The other part of the preparation lies in training. Since getting through the coat change requires that the Lhasa be groomed, start your preparations by teaching the puppy to accept grooming as part of his routine and to lie quietly on his back or sides while you comb and brush him. Prepare yourself also by learning how to groom your Lhasa properly. Refer to any of the books (by Herbel, Helf, Brearly, Nicholas) written about the Lhasa. Most contain excellent grooming suggestions or entire chapters devoted to grooming.
When the coat change does begin, don't get discouraged. It usually lasts less than a month. Set aside time each day to groom your Lhasa. If you don't have time to brush him completely each day, then at least do some spot grooming in the troublesome areas (neck, insides of legs, behind the ears) on a daily basis. Don't go longer than two days without a complete brushing, though. Those darn mats surprise you -- a puppy may not look matted, but his undercoat may be a real mess.
My best advice is to be aware of what will happen, be prepared to do some heavy-duty grooming for about 3 weeks, train your puppy early to accept being groomed, watch for and take care of tangles and mats as they appear, and do not put off grooming thinking the mats will disappear by themselves (they don't!). Finally, don't be discouraged; just hang in there until it's over -- the coat change period really does end!