Hi Sir or Madam,
My name is XXXXX XXXXX I've been with Just Answer since 2006. It will be my pleasure to work with you.
It's possible your dog is suffering from vestibular disease. Symptoms include standing with legs spread out, swaying, head tilt, abnormal eye movement, walking sideways, falling over and may include vomiting. There are a few things that can cause this condition such as an ear infection, some medications and old age. Have your Vet check your dog for this condition.
Here are some great sites on this condition:
The good news is that if this is the problem and it is due to old age, the condition normally resolves itself over a few weeks. Your vet will most likely prescribe dramamine or bonine to help with the symptoms. You can read about dramamine and bonine usage, precautions and dosage here:
In many cases, as long as the dog is eating and not too sick, we will let it resolve on its own. However, if she hasn't had a checkup recently, you may want to do it as organ failure can cause incoordination and a loss of appetite as well. However, the head tilt and incoordination are classic signs of a vestibular problem.
I hope this information is helpful to you.