Health Problems Known to the Yorkshire Terrier Breed
Information gathered from various sources including Wikipedia and breed books

Portosystemic Shunts
(Liver Shunt)

A portosystemic shunt (PSS), also known as a liver shunt, is a bypass of the liver by the body's circulatory system. It can be either a congenital (present at birth) or acquired condition. Congenital PSS is a hereditary condition in dogs and cats, its frequency varying depending on the breed. The shunts found mainly in small dog breeds such as Miniature Schnauzers and Yorkshire Terriers, and in cats such as Persians, Himalayans, and mix breeds are usually extrahepatic (outside the liver).

Congenital PSS is caused by the failure of the fetal circulatory system of the liver to change. Normally, the blood from the placenta bypasses the liver and goes into circulation via the ductus venosus, a blood vessel found in the fetus. A failure of the ductus venosus to close causes an intrahepatic shunt, while extrahepatic shunts are usually a developmental abnormality of the vitelline veins, which connect the portal vein to the caudal vena cava. Thus in the juvenile and adult animal with PSS, blood from the intestines only partly goes through the liver, and the rest mixes into general circulation. Toxins such as ammonia are not cleared by the liver. Most commonly, extrahepatic shunts are found connecting the portal vein or left gastric vein to the caudal vena cava.

Symptoms of congenital PSS usually appear by six months of age and include failure to gain weight, vomiting, and signs of hepatic encephalopathy (a condition where toxins normally removed by the liver accumulate in the blood and impair the function of brain cells) such as seizures, depression, tremors, drooling, and head pressing. Urate bladder stones may form because of increased amounts of uric acid in circulation and excreted by the kidneys. Initial diagnosis of PSS is through laboratory bloodwork showing either elevated serum bile acids after eating or elevation of fasting blood ammonia levels, which has been shown to have a higher sensitivity and specificity than the bile acids test.

There is no cure for a liver shunt, but often times can be corrected with surgery.

Collapsing Trachea

Tracheal collapse is a condition characterized by incomplete formation or weakening of the cartilagenous rings of the trachea resulting in flattening of the trachea. It can be congenital or acquired, and extrathoracic or intrathoracic. Tracheal collapse is a dynamic condition. Collapse of the cervical trachea (in the neck) occurs during inspiration; collapse of the thoracic trachea (in the chest) occurs during expiration. Tracheal collapse is most commonly found in small dog breeds, including the Chihuahua, Pomeranian, Toy Poodle, Shih Tzu, Lhasa Apso, Maltese and Yorkshire Terrier. Obesity is a common contributing factor in dogs with tracheal collapse.

Congenital tracheal collapse appears to be caused by a deficiency of normal components of tracheal ring cartilage like glycosaminoglycans, glycoproteins, calcium, and chondroitin. Acquired tracheal collapse can be caused by Cushing's syndrome, heart disease, and chronic respiratory disease and infection.

Symptoms include a cough (often called a "goose honk cough" due to its sound), especially when excited. This cough is usually paroxysmal in nature. Other symptoms include exercise intolerance, respiratory distress, and gagging while eating or drinking. Tracheal collapse is easily seen on an x-ray as a narrowing of the tracheal lumen. Treatment for mild to moderate cases include corticosteroids, bronchodilators, and antitussives. Medical treatment is successful in about 70 percent of tracheal collapse cases. Severe cases can be treated with surgical implantation of a tracheal stent (inside or outside of the trachea) or prosthetic rings. Extraluminal (outside the trachea) stenting is generally only used for tracheal collapse in the neck region. Intraluminal stenting has shown more promise for success with intrathoracic cases, especially using nitinol, a type of shape memory alloy composed of nickel and titanium. Potential problems include stent migration and fracture.

Luxating Patella

Luxating patella (or trick knee or subluxation of patella), is a condition in which the patella, or kneecap, dislocates or moves out of its normal location.Patellar luxation is a common condition in dogs, particularly small and miniature breeds. The condition usually becomes evident between the ages of 4 to 6 months. Most cases of patellar luxation are medial and this is frequently a congenital problem in toy and miniature breed dogs. Breeds showing a predisposition for medial patellar luxation include miniature and toy poodles, Yorkshire terriers, Pomeranians, Pekingese, Chihuahuas and Boston Terriers. It can be caused by some form of blunt trauma, or may be a congenital defect. In congenital cases, it is usually bilateral.

Diagnosis is made through palpation of the knee. X-rays are necessary in some cases. The luxating patella often causes no or very slight symptoms. There may be intermittent limping in the rear leg. Osteoarthritis can develop secondarily.

There are four diagnostic grades of patellar luxation[4], each more severe than the previous:

• Grade I - the patella can be manually luxated but is reduced (returns to the normal position) when released;
• Grade II - the patella can be manually luxated or it can spontaneously luxate with flexion of the stifle joint. The patella remains luxated until it is manually reduced or when the animal extends the joint and derotates the tibia in the opposite direction of luxation;
• Grade III - the patella remains luxated most of the time but can be manually reduced with the stifle joint in extension. Flexion and extension of the stifle results in reluxation of the patella;
• Grade IV - the patella is permanently luxated and cannot be manually repositioned. There may be up to 90¼ of rotation of the proximal tibial plateau. The femoral trochlear groove is shallow or absent, and there is displacement of the quadriceps muscle group in the direction of luxation.

Grades III and IV, as well as most grade II cases, require surgery to correct, if the animal has difficulty walking. The surgery involves a sulcoplasty, a deepening of the trochlear sulcus that the patella sits in.Additional help can be given with the use of pet ramps, stairs, or steps. These can help the animal travel from one place to another, especially up and down, without adding any pain or damage to the patella.

Hypoglocemia
(Sugar Drops)

Low blood sugar in puppies, or transient juvenile hypoglycemia, is caused by fasting (too much time between meals). In rare cases hypoglycemia may continue to be a problem in mature, usually very small, Yorkies. It is often seen in Yorkie puppies at 5 to 16 weeks of age. Very tiny Yorkie puppies are especially predisposed to hypoglycemia because a lack of muscle mass makes it difficult to store glucose and regulate blood sugar. Factors such as stress, fatigue, a cold environment, poor nutrition, and a change in diet or feeding schedule may bring on hypoglycemia. Low blood sugar can also be the result of a bacterial infection, parasite, or portosystemic liver shunt. Hypoglycemia causes the puppy to become drowsy, listless (glassy-eyed), shaky and uncoordinated, since the brain relies on sugar to function. Additionally, a hypoglycemic Yorkie may have a lower than normal body temperature and, in extreme cases, may have a seizure or go into a coma. A dog showing symptoms should be treated by a veterinarian immediately, as prolonged or recurring attacks of hypoglycemia can permanently damage the dog’s brain. In severe cases it can be fatal.

**In our experience with sugar drops, it is relatively easy to bring a puppy out of episode with a generous dose of NUTRI-CAL and NUTRI DROPS. These are basically liquid sugar and normally brings them right up after several minutes.