Small Breed can be prone to these Ailments

 

                                                 

(LP) Luxating Patella

LP is a genetic defect found in small dogs. n some dogs, because of malformation or trauma, the ridges forming the patellar groove are not prominent, and a too-shallow groove is created. In a dog with shallow grooves, the patella will luxate (jump out of the groove) sideways, especially toward the inside. This causes the leg to 'lock up' with the foot held off the ground.

Collapsing Trachea

The trachea, also known as the windpipe, is an important structure which connects the throat to the lungs. It is composed of 35- 45 C-shaped rings of cartilage that are joined by muscle and ligaments to create a tube-like structure. It serves the purpose of directing air into the respiratory tract. When the cartilage rings are flattened from the top to the bottom, the trachea is said to be collapsed.

Liver Shunt

A Liver Shunt is a blood vessel that carries blood around the liver, instead of through it. In some animals a liver shunt is a birth defect, known as "congenital portosystemic shunt". In others, there are multiple small shunts, known as "acquired porotsystemic shunts", and they form because of severe liver disease such as cirrhosis. Toxins, especially ammonia, build up in the blood stream and the dog has seizures due to increased ammonia levels. The liver is usually smaller than normal and will have decreased liver function.

(HMD) Hepatic Microvascular Dysplasia

Most of the blood that is carried to the liver for these processes arrives via the portal vein, which drains the intestines, stomach, pancreas, and spleen. Within the liver, the portal vein branches into smaller and smaller vessels so that the blood can percolate throughout the tissues to each liver cell. When these microscopic vessels are abnormal on liver biopsy, the condition is called "hepatic microvascular dysplasia (HMD or MVD)" or "portal atresia". When the microscopic vessels within the liver are underdeveloped or absent, the liver becomes small ("atrophied") and the animal can no longer process toxins or make proteins necessary for growth and normal function.

                              Thanks to YorkieChat for this information