She is not an old dog. I can understand her pucking peeing and pooing, because this can due to dietary problems and the diarrhoea can also be a a symptom of this. However I am baffled by the leg problems and the salivation.
In my experience vets don't acknowledge that grain in dog food can cause horrendous problems and I think that you should look at the ingredients in the food which you are giving your dog. I will paste the info on the problems which my dog had due to grain in her food. Before I do so, I agree that your dog should not be kennelled outside. She could be stolen, abused and attacked by other animals and the extreme tempratures could be a problem.
You have not said how long that your dog is left alone during the day, perhaps of problems could be due to stress and separation anxiety.
I have learnt by my mistakes. My present dog had dreadful problems because of the food which I gave her, I experimented with dog food, I tried raw diets, cooked diets and over the years I tried various dog foods. She did not like the raw diets and the dog food that I gave her resulted in diarrhoea. As an experienced dog owner I introduced any changes gradually. Nevertheless my dog still had problems. She was eight years old before I resolved her problem.
Eventually, because of my researches on the Internet I found that the experts have discovered that GRAIN in our dog’s diet causes many problems. I now know that grain creates acidity in the blood. This causes skin problems, digestive issues, allergies, sickness, constipation, diarrhoea, anal gland problems etc.,
if your dog has skin problems or any of the above problems PLEASE CHANGE THE DIET. Avoid Grain, rice, beef derivatives and dairy food
I now give my dog a dried food which uses beet for fibre and fish. It’s called Fish4Dogs and I buy it on the Internet. Look on the Internet and investigate yourself. Gluten free dog food is not enough to help our dogs, it MUST BE GRAIN FREE.
A rapid change of diet will upset your dog; any change of diet must be done gradually. Do please change to a grain free diet. I have had sixteen dogs throughout the years and they have had various problems. Perhaps if I had known about the dangers of GRAIN they would have had fewer problems. .