Dental Problems

• Since it is hard for small dogs to chew the large chunks of dry dog food, most owners feed them canned food. This can lead to dental problems, which in turn can lead to other conditions, such as heart problems.
  
  

Broken Bones

• Small dogs have small bones that break easily, even just from normal play.
  
  

Viruses

• All sizes of dogs can get viruses, but a virus can overwhelm a small dog's immune system much faster than a large dog, making a small dog much sicker, much faster.
  
  

Hypoglycemia

• Hypoglycemia, or low blood sugar, is prevalent in small dogs, because they have a faster metabolism than a larger dog.
  
  

Hip Dysplasia

• Hip dysplasia is a genetic condition in which the hip joint does not form correctly. It can cause a painful limp; if not taken care of, it can cause a permanent disability.