Why Is Salt Controversial?
Salt (sodium chloride) is used in many perishable foods, including commercial kibble (source), as a natural preservative that prevents the proliferation of microbes (mold and bacteria). It does this by “sucking” the moisture from it, leaving it too dry to allow microbial growth.
For the same reason that salt preserves food, this mineral, when used in large doses, is dangerous to dogs and can lead to salt toxicity or hypernatremia, and hypertension (source, source, source). Too much salt for dogs can cause them to become very thirsty and urinate more frequently, which could lead to dehydration (source).
When large doses of sodium chloride have been ingested by the dog to the point of toxicity, your pet may also experience vomiting, diarrhea, muscle tremors, depression, elevated temperature, seizures, and even death.
However, most animals can tolerate a higher concentration of salt as long as they have a continuous supply of freshwater to flush it from their system.
Salt: the good news
Dogs need salt for their cells to function and a healthy amount of it is between 0.25g – 1.5g per 100g of food. At these levels, salt isn’t bad for dogs and helps maintain cellular functions like fluid balance, acid-base balance and nerve signal transmission.
Your dog also needs the ‘chloride’ in sodium chloride to produce the stomach’s hydrochloric acid, which helps with their digestion. So far, all good.
Can dogs eat too much salt?
Salt is going to be bad for dogs if they eat too much of it by accident (rock salt left on a table for example) or if there’s too much salt in their dog food. If this happens they’ll combat it by drinking more water.
Too much salt causes problems including:
Salt poisoning (hypernatremia) is life threatening and needs emergency veterinary assistance. As cells start to release water to even out the levels of salt in your dog’s blood, your dog may become stiff and lethargic, and may start convulsing.
Why Salt is Bad for Your Dog
Before you offer your dog a morsel of your salty snack, let’s look at the effects salt can have on your dogs’ health and discuss just how much is too much.