What genetic health tests should Yorkshire Terriers have done before they are bred?

http://infoinn.ngwaagan.ca
A very informative website, you can also get much information in website.
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Look up your breed,find what problems they could accur during their life that are really serous

Make sure they are AKC,or Canadian kennel club registered,if they are not,don't breed

http://www.canadasguidetodogs.com/terrier/yorkshirearticle1.htm

Campylobacteriosis
Campylobacteriosis is a bacterial imbalance in the digestive tract and produces acute infectious diarrhea in puppies and kittens. Commonly mistaken for Parvovirus, this disease, however, requires different treatment. If you suspect that your dog is affected, have him specifically tested for "Camby". It should also be noted that the disease can be transferred between humans, cats, dogs and other livestock. Initial signs include fecal mucus sheath and gets progessively softer until watery and may also contain blood. Symptoms may also be accompanied by vomiting which may or may not also contain blood. Feces are usually mustard in colour and have a sweet/flowery aroma.

Coccidiosis
Coccidia are microscopic parasites that live within cells of the intestinal lining causing diarrhea in puppies and occasionally, adult dogs. Because they live in the intestinal tract, coccidia is commonly mistaken for worms.

Collapsing Trachea
Collapsing Trachea is a problem common to Toy breeds. Symptoms of the condition include shortness of breath, coughing and fatigue, and usually appears after the age of five years but they can begin as early as birth.
For more information, see: Collapsed Trachea: The Health Problem Every Owner of a Small Dog Should Understand

Cushing's Disease
Cushing's disease is the result of the overproduction of cortison, a natural steriod hormone, by the adrenal glands. In the majority of cases, the disease is caused by a lesion in the pituitary gland at the base of the brain that overstimulates the adrenals, while in about 20 percent of cases one of the adrenal glands itself will have a tumor that excretes cortisol independent of what's happening in the body. About half of those tumors are malignant and spread, and about half of them are benign and generally remain small.
Typical signs of Cushing's Disease include increased thirst and urination, panting, hair loss (usually on the trunk) and weakness. It is rare for a dog under the age of five years to have Cushing's Disease.

Eclampsia
Eclampsia is an acute, life-threatening disease caused by low calcium levels (hypocalcemia) in dogs and more rarely in cats. A lactating animal is especially susceptible to blood calcium depletion because of lactating. Signs of Eclampsia are most often seen 1-3 weeks after giving birth, but it can occur anytime, even while pregnant. Smaller breed dogs are at a high risk. Initial signs include restlessness and nervousness, followed by a stiff gait or wobble when walking and she may also appear disoriented. Eventually, the dog may be unable to walk and will exhibit extreme rigidity in the legs. Her body temperature may increase to over 105°F and respiration rate will increase. At this point, treatment is absolutely necessary. Seek veterinary attention immediately and prevent the puppies from nursing for a minimum of 24 hours (use a milk replacer supplement for the pups). Eclampsia can be rapidly corrected through the use of intravenous calcium supplementation.

Hemorrhagic Gastric Enteritis (HGE)
HGE is particularly dangerous to Toy and smaller breed dogs. Any kind of bacterial diarrhea can quickly dehydrate a dog, and the little dogs are at greater risk of dehydration as they have little weight to lose. It may take two to ten days after exposure before signs of HGE are apparent. Symptoms start with vomiting, lethargy, refusal to eat, and progresses to mucous covered stools, loose stools, severe diarrhea, and bloody diarrhea. A culture should be done as soon as possible to determine the exact bacteria to be treated.

Hypoglycemia
Hypoglycemia occurs when the blood sugar levels (glucose) fall below normal. Glucose is what the body uses as fuel and is necessary for the brain tissue and muscles to function. Hypoglycemia is common in Toy breeds and frequently seen in young Toy puppies. The affected puppy may appear confused, disoriented, drowsy, have the shivers, stagger, collapse, fall into a coma, or have seizures. Typical signs include listlessness, depression, staggering gait, muscle weakness and tremors. Hypoglycemia must be treated.

Legg-Calve-Perthes (LCP)
L'egg Perthes, also known as Legg-Calve-Perthes disease, is a disease of the hip joints of small breeds of dogs. The head of the femur begins to die and disintegrate causing limping, pain, and eventually, arthritis. It usually appears between the ages of six and twelve months. Treatment of the condition varies depending on the severity of the signs seen. In mild cases, enforced rest may be sufficient to allow healing while more sever cases may require surgery.

Liver Shunt
Liver Shunt, also known as Portosystemic Shunts, are abnormal veins that allow blood from the intestine to bypass the liver. When a shunt is present, blood bypasses the liver with disastrous and often fatal consequences. Ammonia and other toxins are not metabolized or removed from the circulation, resulting in signs of hepatic encephalopathy (type of brain inflammation caused by high levels of ammonia and other toxins in the blood). Symptoms can include stunted growth, persistent vomiting and diarrhea, weight loss and seizures. However, it is possible for symptoms to be very subtle as well — increased urination, thirst and salivation. Liver shunts are operable but not always successful. The errant blood vessels may be inside or outside the liver and those that are inside are much more difficult to repair.

Pancreatitis
Pancreatitis is an inflammation of the pancreas. When digestive enzymes that are normally excreted into the intestinal tract are activated in the pancreas instead, they cause inflammation. Foods high in fat, or a lot of greasy table scraps, tend to trigger pancreatitis.
This is a serious and potentially life-threatening disease. Affected animals will have severe abdominal pain, loss of appetite, lethargy, depression, vomiting and diarrhea. Dehydration is also a danger.

Patella Luxation
Patella Luxation, also known as slipping kneecaps, slipping stifle, is a relatively common condition in the Yorkshire Terrier and often results in intermittent lifting of one or both hind legs when walking or running. It may be recessively inherited and therefore, afflicted animals should not be bred. Corrective surgery is usually very successful.

Reverse Sneezing (Pharyngeal Gag Reflex)
Pharyngeal Gag Reflex is a dramatic, rapid inhalation and exhalation of air through the nasopharynx. Dogs may do this when they have a mild irritation at the back of their throat. Often confused with seizures or gasping for air, it is usually a harmless event.
Reverse sneezing is not really a health problem but it is very common in Toy breeds and owners should be aware of it. Characterized by honking, hacking, or snorting sounds, it usually happens when a dog is excited or after drinking, eating, running around, or pulling on a leash. The dog will usually extend his neck while gasping inwards with a distinctive snorting sound. Usually, gently rubbing the throat of the affected dog will help stop the spasms.

References
~ Health & Nutrition Section of Canada's Guide to Dogs

~ Legg Calvé Perthes Disease by Fred Lanting

~ Canine Inherited Disorders Database

~ Patellar Luxation in Small Breed Dogs by Teri Dickinson, DVM
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OFA heart, hips, elbows. CERF. Thyroid. Those are the basics. I will see if I can find breed specific required testing.

BTW, we don't need "well rounded" puppies. We need dogs that are going to contribute to the gene poole as model dogs.
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Is your friend's Yorkie a registered pedigree dog? Does this dog have any titles? If not there is no way anyone with a quality registered bit*ch will use her dog. She will only find back yard breeders who would use her dog.
I'm guessing this dog does not have pedigree papers or the owner would know exactly what health testing is required and she also would not be pimping her dog.

It's the owner of a registered bit*ch, after studying the lines of the dog, approaches the owner of a suitable stud dog. When the owner of a male looks for a female for breeding it is referred to as pimping the dog.

FYI, she is not trying to spay him…spaying is the name of the surgery carried out on female dogs when they are desexed. Males used for breeding are stud dogs.
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I want to make some money!
Breeding, and doing it right, is an expensive undertaking. By the time you've picked out a good bitch, waited for her to grow old enough (minimum age: two years before breeding), picked out the best dog to mate her with, gone through all the health checks she needs, ensured that the dog you want to use also passes the same health checks, you've invested a lot of time and effort. You still have to pay a stud fee (or give a puppy back), you have potential extra expenses during pregnancy, you have the time and expense of whelping (either you take time off from work or something goes wrong and you have to take her in to the vets). You need to keep the puppies for a minimum of 8 weeks before sending them to their homes; you need to advertise and find good homes for the puppies, you need to make sure they have had their shots before going. You may have possible vet bills if the puppies require extra attention. If some of the puppies die, or you have a smaller than usual litter, you may not get as much money from the sale of the puppies as you had though. There are even potential problems later on with dissatified customers! You are better off consulting with a financial wizard about investing the money you would otherwise spend and lose on breeding!

Breeders frequently count themselves lucky if they break even.

So I should breed when…?
The only reason you should be breeding is that you honestly feel that you are improving your breed by doing so. There are far too many dogs in the country to breed without good reason. A dog in a breeding program must be one whose genetic history you or its breeder is intimately familiar with. Such a dog must represent the best efforts of its breeder at that point. Such a dog must have good points to contribute, whether that is in good conformation, good performance or whatever. Such a dog must have some evidence of external evaluation. That is, others besides the breeder or the owner must also think that the dog is a good representive of its breed. That usually translates into titles, whether for conformation, obedience, field, herding, or whatever is appropriate for that breed. Such a dog must be tested as it matures for any problems that tend to appear in its breed, whether that is hip dysplasia, patellar luxation, von Willebrand's, cataracts, PRA, fanconi syndrome, subaortic stenosis, etc.

Some Yorkies are prone to bronchitis and early tooth decay, poor tolerance of anaesthetic, and delicate digestion. Exotic treats should be avoided. They sometimes suffer paralysis in the hindquarters caused by herniated disks and other problems of the spine. Falls or knocks can cause fractures of fragile bones. Abnormal skull formations in Yorkies measuring less then 8 inches (20cm). Bitches often have trouble delivering.

They take the little teeny, tiny Yorkies and they breed 2 1/2 pounders with 3 pounders … well, they’re playing with genetics. You should NEVER breed a female of any breed less than 5 pounds.
References :
http://www.k9web.com/dog-faqs/breeding.html#i_want_to_make

http://www.barkrescue.net/teacup.htm

The most common genetic faults in Yorkies are: Patellar luxation
Portosystemic shunt (Liver Shunt), Retinal dysplasis, and Tracheal collapse. The only one that there is a test for is the eye diseases, and that will only predict about 50%. The other issues generally appear by age three, with the Liver Shunt appearing around six months. So your friend should have an ortho specialist evaluate his kneecaps, and get him CERF certified for his eyes. Thanks for trying to talk her out of this! Maybe when she sees the cost of health certifications she will change her mind.
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10yrs vet tech, 30yrs dog owner, trainer, exhibitor, rescuer.