Found in the blood and in the fluid that surrounds cells, sodium maintains the cellular environment and prevents cells from swelling or dehydrating. Sodium is also important for maintaining proper nerve and muscle cell function.
Meat, poultry, fish, and eggs are good sources of sodium.
Sodium also might be included in commercial pet foods in the form of table salt (sometimes listed on the ingredient panel as salt). Salt is an important palatant for animals, as well as for people.
The Association of American Feed Control Officials recommends that dry dog foods contain at least 0.3% sodium for both maintenance and to support normal growth and development. This is the minimum recommended levels.
While high sodium intake might cause increased thirst and water consumption, the extra sodium is excreted in the urine of dogs. Healthy dogs are able to consume diets with higher sodium levels than those found in most commercial pet foods without increased blood pressure or gain in body water.
Therefore, the sodium level in commercial pet foods is not a cause for concern in healthy animals.

A veterinarian might recommend decreasing a dog's sodium intake if the animal has some types of kidney, liver, or heart disease, in order to help decrease high blood pressure or the accumulation of excessive body fluid.
Although older dogs might be more likely to develop these diseases, healthy older dogs do not require a low- or reduced-sodium diet.
The sodium level in our dog foods is appropriate for a healthy dog. The sodium content in these foods is balanced in proper proportions with energy, other minerals, vitamins, fats, proteins, and carbohydrates.
Since we cannot directly communicate with our dogs, there are certain behaviours and actions that immediately concern us. One of these behaviours is a dog shaking. No, not the fun way they shake off water starting from their nose all the way to the end of their tail. We’re talking about that full-body trembling you’ve likely seen your pooch do from time to time. Why do they do it? And is it something you should be worried about?
A majority of dog owners in an IAMS™ survey* (64%) think the reason behind a dog shivering is that they are cold. Other top responses were because the dogs are scared (57%) or anxious (54%). High-fives all around because it turns out there are a number of reasons why dogs shake, and all those are possible correct answers. Here are some probable reasons behind a dog trembling:
Just like their owners, dogs will often shiver when cold. Dr. Tammie King, Applied Behaviour Technical Leader at Waltham Petcare Science Institute, says: “Dogs shiver in response to falling temperatures. Dogs with short or no hair are especially susceptible. You should get them warm, put coats on them or bring them inside.”

“Shaking is a response to epinephrine or adrenaline secretion — a sign of anxiety where the dog is on high alert,” says James Serpell, B.S., Ph.D., Professor of Humane Ethics & Animal Welfare at the University of Pennsylvania School of Veterinary Medicine. You may notice this when you’re at the vet or there’s a situation where they feel threatened. Dr. Serpell also offers a way to help in some cases: “Identify what’s triggering the behaviour. Provide them comfort. Going forward, you can gradually desensitise your pet to the thing it’s afraid of.”

This is probably the most comforting answer to every dog owner’s concern. Apart from being a response to anxiety or stress, a dog’s trembling can also be a result of excitement. This trembling or shaking is not a matter of concern and will stop once the animal calms down.
Trembling can also be a sign of serious issues like injury, poisoning, or kidney disease. Dr. Jo Gale, BVetMed CertLAS MRCVS, Senior Manager, Global Science Advocacy at Waltham Petcare Science Institute urges pet owners to be vigilant: “If a pet is unwell in another way, they could be trembling.” If their shaking is accompanied by symptoms like diarrhoea, limping, or vomiting, you should consult your vet straight away.
Shaker syndrome has been observed in white dogs of smaller-sized breeds. It causes shivering in a dog’s entire body. The precise cause of this syndrome is not yet known; however, your vet will be able to prescribe medications upon close examination.
Old age is also a pretty common cause of shaking and shivering in dogs. This is because age reduces tolerance to even a slight amount of cold. Besides that, shaking can also be a result of other old-age-related issues like joint pains or weakening of limbs.
As mentioned earlier, you should immediately consult a vet if, along with shaking, your dog is also experiencing vomiting, limping, or diarrhoea. Even though shaking is a common symptom of old age-related issues, you must take your dog to the vet. If they are suffering from joint pain, early treatment is necessary. It is also advisable to visit a vet if your dog’s shaking or shivering hasn’t stopped even after a few minutes.
Additionally, if you ever notice violent shaking in your dog, it might actually be a seizure. In such a case, rush to an emergency room as quickly as possible.