While the Havanese is a sturdy little animal with significantly less problems than many other toys, you must still do your homework in advance. Do research to learn which disorders are most prevalent in the Havanese. Below is a link to the Havanese Club of America that shows the genetic diseases Havanese are predisposed to:
Be sure to ask the Breeder whether the sire or dam of the puppy you want has a close connection to a dog that has expressed a genetic disorder. If the answer to that question is no, also ask if the sire or dam is a littermate to a dog with an expressed disorder.
You can also go to the OFA (Orthopaedic Foundation for Animals) website to locate any Havanese posted on the open database that have been tested by OFA and diagnosed with a genetic disease.
For example, below is the link on the open OFA data base showing MistyTrails Will'n2B Saranad'd as a dog affected by Legge Cathe Perthes, a disease accepted by both OFA and the Havanese Club of America as genetic in nature. You can see all of Sara's closest relatives, dam, sire, siblings on the post:
Here are MistyTrails Bella Gemma's results showing her to be positive for autoimmune thyroid disease posted in OFA in February 2015:
These post are permanent, thus another good reason for CKC and AKC not to allow duplicate names of dogs within the same breed, a practice that may be designed to confuse the disease results posted on the public OFA data base.
Limiting inherited conditions
"The occurrence of hereditary disorders can certainly be reduced by means of good breeding strategies. In order for this to take place, we must learn how the disorder is actually inherited (the manner of inheritance), learn how to recognize the disease as early as possible, and how to identify carriers of the condition that, other than when it comes to autosomal dominant traits, aren’t clinically affected.
With regard to a lot of the disorders which are thought to be inherited, the precise pattern of inheritance hasn’t been identified. Dog breeds with a greater likelihood of having a disorder, compared to other breeds of dog, are generally said to have a breed predisposition. Ideally, afflicted dogs and also their near relatives must not be utilized in breeding programs."
Eliminating all close relatives of afflicted dogs from breeding can negatively affect diversity within the breed so this may not the best solution to this problem.
However, a Breeder should be able to tell you if the dam or sire of the puppy you are looking at is a close relative of an animal that has expressed one of the genetic diseases noted in the link above from the National Havanese Club of America.
You can also ask the Breeder to explain WHAT they did to ensure that breeding using a close relative of an affected animal has been done in such a way as to minimize a predisposition for that disease within the breed.
The Breeder should also be able to tell you WHY that specific breeding was an optimal choice - i.e.: to improve the breed and how that breeding did that.
Popular Sires - A whole different ballgame
Also, if the Stud is one that is used frequently, all bets are off. This boy could be a popular sire and scew the diversity of the breed both as a carrier AND because his genes are being over-extended within the breeding pool. So ask how many litters the stud has thrown already.
For example, Alice, shown below, came from a stud that threw, between 2010 and 2015 (with the bulk being registered between 2010-2012), 38 litters/177 puppies. Alice's family did not know that the puppy they were purchasing came from a stud being used so broadly across a kennel breeding group with a closed breeding pool.
Double, triple and quadruple line breeding - a very poor practice
Finally, look at the pedigree of your puppy carefully. If you can see the same dogs on both sides of the pedigree chart, this is not a good thing for your puppy. Doubling up lines on both sides can extend the possibility for problems to occur.
You can see an example of this below from Sara's Story where this boy, Boy A, has four dogs doubled up on both sides of his pedigree! Avoid any kind of situation like this in your puppy's pedigree. Even one dog is too many because you do not know what that dog may be carrying in his genes! Keep your puppy's pedigree diversified!
There is a lot to think about when you are buying a puppy and you have the right AND the responsibility to ask all of these questions! If the Breeder becomes at all defensive, walk away. This is NOT the Breeder for you.