It sounds like your dog is having gran mal seizures. The reaction after the seizure (postictal stage) is typical, but lasting longer than normal.
Idiopathic (unknown cause) epilepsy is usually first seen between 4-8 years of age and is not likely to be the problem in this case.
Causes of seizures in older dogs include:
Let me know if you have follow up questions.
The main differentials seem to be functional pancreatic tumor (glucose while acting normal does not rule this out), brain tumors that do not show up on x'ray (we see air, soft tissue and bone on film. A small tumor may not change the radiograph), encephalitis, other brain disorders, and toxoplasmosis, encysted parasites... that I didn't put in the first message.
As an aside... I saw a neurologic horse that had at least one seizure. Liver enzymes were surprisingly OK, but the final diagnosis was hepatic encephalopathy secondary to hepatic lymphosarcoma.
Also.... there is a lot that we don't know and many causes that we never figure out. You can treat empirically while you continue to look for the cause.
The parasites I mentioned are ones that migrate to the brain. Toxoplasma, Ascarids (roundworm larva) and Neospora are examples of common parasites that can encyst in the brain. The parasites could have been there for years (since puppyhood) or from a more recent infection. They are widely distributed in places animals live including woods, sidewalks and parks. They are usually picked up from infected feces or places where infected feces have been (sidewalks). Parasites can cause seizures. That does not mean that they caused your pupper's seizures.
If the softball sized mass was food, it would be not be there if another image was done. Usually, a cup of food has moved out of the stomach in well under 4 hours. However, a liver mass should not be causing seizures because it does not affect enough of the liver to interfere with the normal function. Seizures from liver damage require the liver to be severely affected so that it is not able to function.
Seizures have preictal and postictal phases. Vomiting, diarrhea and urination can occur in any of the phases including during the seizure.
Seizures always originate in the brain. The cause must be something that affects brain function. Masses (tumor, encysted parasites), inflammation (encephalitis), lack of needed nutrients (glucose, calcium, oxygen) are major known causes.
Seizures by themselves do not cause weight loss. If they interfere with eating, they can.
Have you and your vet treated the seizures with anything yet?
Seeing if there is more of a pattern makes sense and is a good reason to wait before treating her.
I often give clients valium to use at the time of a seizure when waiting to figure out if there is a pattern or for dogs that seizure infrequently. It is given intrarectally using a preloaded syringe without a needle. It is absorbed better from the rectum than by injection and is easy for clients to do although most grimace when I tell them how I want it given.
There are some not much fun diseases in the SW desert area, but nothing that I can link to seizures in an indoor dog.
I doubt she has intestinal worms. The worms I mentioned would be in her brain. They damage the cells around them very much like a tumor does. Your girl probably doesn't have these, but they are a reason some dogs develop seizures.
I'll let you know if I think of anything else.
You may get to that point, but it doesn't sound like it is time yet. Even if it is a brain tumor, you treat what you can for as long as you can so long as she is happy and love her until it is time. You will know when it is time.
I've been a vet for a bunch of years and have followed many of my patients from puppyhood to old age. I also have my own critterkids. It's one day at a time from smiling at the puppy antics through a lot of happy and sometimes not happy days to the sadness of having them leave. Overall, I smile more than I cry....I try to help that happen for my clients also.
Smile at your girl and give her a hug!