The Importance of Sodium in Your Dog’s Diet: Benefits, Risks & What Owners Should Know

Expert Advice

11 Sept

Discover why sodium is essential in your dog’s diet. Learn how much sodium dogs need, signs of deficiency or excess, and what health conditions mean for sodium intake. Evidence-based guidance from The Canine Dietitian.

The Importance of Sodium in a Dog’s Diet: What Every Dog Owner Should Know

Sodium is often misunderstood when it comes to dog nutrition. As humans, we’re constantly reminded to cut back on salt for our own health, so it’s no surprise that many dog owners worry about how much sodium their dogs should eat.

The truth? Sodium is an essential nutrient for dogs. It plays a vital role in hydration, muscle and nerve function, and even your dog’s heartbeat. But — just like with any nutrient — balance matters. Too little sodium can be just as dangerous as too much.

In this article, we’ll cover:

Why sodium is essential for dogs
Signs of sodium deficiency and excess
How much sodium your dog really needs
The role of sodium in conditions like heart disease, kidney disease, and Addison’s
How to evaluate sodium in commercial and homemade diets
Practical tips to make sure your dog gets it right

Why Sodium Matters in Dog Nutrition

Sodium (Na) is a macromineral — a mineral needed in relatively large amounts. Working alongside chloride (Cl) and potassium (K), sodium regulates:

Fluid balance and hydration
Muscle and heart function
Nerve impulse transmission
Nutrient transport (like glucose and amino acids)
Acid–base balance in the blood

According to both the National Research Council (2006) and FEDIAF (2023) guidelines, sodium is a non-negotiable nutrient in a dog’s diet. It’s not stored long-term, which means dogs must consume adequate sodium daily to stay healthy.

The Roles of Sodium in a Dog’s Body

1. Fluid Balance & Hydration

Sodium helps regulate how much water sits inside and outside your dog’s cells. Without it, dehydration and low blood pressure can occur — even if your dog drinks plenty of water.

2. Muscle & Heart Function

Sodium is needed for muscle contractions — and since the heart is a muscle, it also plays a direct role in maintaining a healthy heartbeat.

3. Nerve Signals

Every movement your dog makes relies on sodium. It enables the electrical impulses that let nerves communicate with muscles.

4. Nutrient Transport

Glucose and amino acids rely on sodium for transport into cells. Without it, your dog’s body struggles to access energy from food.

How Much Sodium Does a Dog Need?

FEDIAF (2023): 0.2% on a dry matter basis (DMB)
AAFCO: 0.08% as-fed minimum

These requirements may vary with age, health, activity level, and climate (dogs in hotter climates may lose more sodium through panting).

Sodium Deficiency in Dogs (Hyponatremia)

Hyponatremia can develop if a dog is:

Fed an unbalanced homemade diet
Drinking excessive water
Suffering from chronic vomiting or diarrhoea
On diuretics or diagnosed with Addison’s disease

Symptoms include:

Lethargy or weakness
Disorientation
Vomiting/diarrhoea
Low blood pressure
Seizures or collapse (severe cases)

Study Highlight: Feldman et al. (2005) reported that sodium imbalance is a critical concern in dogs with Addison’s disease, and correcting it is vital for survival.

Sodium Excess in Dogs (Hypernatremia)

Hypernatremia usually occurs due to:

Salt poisoning (table scraps, ham, crisps, sea water, salt dough)
Lack of access to fresh water
Underlying health conditions like diabetes insipidus

Symptoms include:

Excessive thirst and urination
Vomiting
Tremors or seizures
Disorientation
Coma in extreme cases

Case Study: A 2011 review reported multiple cases of dogs ingesting salt dough from holiday decorations, leading to fatal hypernatremia.

Sodium and Dog Health Conditions

1. Heart Disease

In the past, strict sodium restriction was standard for dogs with heart disease. Today, research suggests that overly low sodium may worsen outcomes.

Study: Freeman et al. (2013) found that aggressive sodium restriction can activate hormonal systems (RAAS) that make symptoms worse.
Takeaway: Dogs in early heart disease often do well with normal sodium levels. Controlled restriction is typically reserved for advanced cases under veterinary supervision.

2. Kidney Disease

Dogs with CKD often require adjusted sodium intake. Too little can reduce appetite and worsen dehydration, while too much may contribute to high blood pressure.

Study: Polzin (2011) emphasised that moderate — not extreme — sodium control is best for managing CKD.

3. Addison’s Disease

Dogs with Addison’s struggle to retain sodium, meaning they may need higher sodium intake as part of treatment.

Sodium in Commercial vs Homemade Diets

Commercial Dog Foods

Most complete foods (kibble, wet, raw, cold-pressed) already meet sodium needs. The bigger risk? Treats and table scraps, which can contain excessive salt.

Check the label for:

Sodium or salt listed as an ingredient
Compliance with FEDIAF or AAFCO guidelines

Homemade Diets

Muscle meats are naturally low in sodium, making homemade diets a common cause of deficiency. Adding measured sodium is essential for balance.

Safe sodium sources for home cooking include:

Small, measured amounts of iodised or Himalayan salt
Kelp (provides iodine too)
Sodium chloride supplements
Unsalted bone broth

Always seek professional help when balancing a homemade diet.

References & Further Reading

NRC (2006). Nutrient Requirements of Dogs and Cats. National Academies Press.
FEDIAF (2023). Nutritional Guidelines for Cats and Dogs.
Feldman, E. C., Nelson, R. W. (2005). Canine and Feline Endocrinology and Reproduction. Saunders.
Freeman, L. M., Rush, J. E. (2013). Nutrition in Cardiac Disease. J Vet Intern Med, 27(6), 1332–1344.
Polzin, D. J. (2011). Chronic Kidney Disease in Small Animals. Vet Clin N Am, 41(1), 15–30.
Gwaltney-Brant, S. M. (2012). Toxicology of Sodium in Animals. In Veterinary Toxicology.

Final Thoughts: Should You Worry About Sodium?

For healthy dogs, sodium isn’t something to fear — it’s something to manage. Most commercial diets already provide adequate sodium, but if your dog is on a homemade diet, has a health condition, or is taking long-term medication, sodium levels may need closer attention.

If you’re unsure whether your dog’s diet is balanced, book a consultation with The Canine Dietitian for tailored guidance.

Complete the FREE DIET ASSESSMENT FORM and get back a report within 48 working hours from The Canine Dietitian

Sally Barker