In addition to diabetes, service dogs can be trained to detect a host of other medical issues.

Cancer: A growing body of research shows dogs can sniff out the presence of bladder, skin, lung and breast cancers.

Seizures: Dogs can be trained to bark to alert people when their owners are having seizures. Trained dogs will lie down to protect their owner from injury during a seizure. In some cases, dogs have been known to sense when a seizure is about to happen.

Heart attacks: It's unclear whether the dog is reacting to a change in odor or behavior, but there are many reports of dogs becoming agitated and barking at the early signs of a heart attack.

Psychiatric disorders: Such as PTSD, schizophrenia and bipolar disorder. Dogs can be trained to spot changes in behavior that indicate the onset of panic attacks, hallucinations and paranoia. They can be trained to remind owners to take medications when symptoms first appear.

Allie Shah