How can I tell if my dog is dying?

Shelly, you've posted a lot of questions recently about your concern for your dog's health. If you haven't already, I HIGHLY recommended that you bring her to a vet. Occasional diarrhea, vomiting, lethargy, etc. can happen in all dogs, but if it's all coming at once, that is an indication that something is very wrong. I too have had an older dog show his age and eventually pass, but it was a slow decline in overall health, not a sudden change like the ones you've described. For the sake of your dog, I would suggest going to a vet ASAP. I assume by all your posts that you're worried about her, and I think talking with a medical professional will help you decide what is best for your dog.

The signs dogs give us when it’s time to say goodbye. 1.)  Prolonged Lethargy/Disinterest This is the most common sign that the dying process has begun.  Lying in one spot (oftentimes a quiet spot where they don’t usually lay), not interested in toys or walks, barely acknowledging family members — in other words, just not acting like themselves.  Sometimes dogs can become lethargic due to other health issues, but if you have ruled this out and it lasts more than a day, it may be a sign your dog is ready to say goodbye. 2.)  Stops Eating/Drinking You know something is wrong when your dog refuses food.  If your dog is at this point, you can offer him the tastiest treat imaginable and he will not eat it.  He will also stop drinking water.  This is due to the beginning of his organs shutting down.  He no longer has the sensation of hunger or thirst.  You can try to keep him hydrated by giving him water in a dropper or turkey baster, but if he won’t swallow it, there’s not a whole lot you can do.  Again, just because a dog stops eating and drinking for a day or so, doesn’t mean he is dying, so rule out other health issues first. 3.)  Loss of Coordination If your dog does get up and move around, he may be very wobbly or act disoriented.  He may shake or convulse while lying down.  If you can, keep him in a confined, quiet, comfortable area and remove anything he may bump into or knock over. 4.)  Incontinence A dying dog will lie in one spot and not even move to relieve himself.  He may have diarrhea.  This is another signal that your dog’s internal organs are shutting down.  It is important during this time that you keep him and his bed clean and dry. 5.)  Labored Breathing Towards the end, many dogs display difficulty breathing.  Their breathing could be uneven, with lengthy gaps between inhaling and exhaling. 6.)  Seeking Comfort Some dogs will know their time is approaching, and will look to their people for comfort.  Stay with your dog and reassure him with gentle stroking and a soft voice.  As difficult as it is, try not to break down emotionally during this time.  Do everything you can to hold it together so as not to distress your dog.

A sign of your old aged dog getting ready to pass is that they stop eating and drinking.