What Does Sodium Mean in Dogs and Cats?
Quick answer
Sodium is an electrolyte that helps control fluid balance and nerve function. High sodium usually reflects water loss or not drinking enough. Low sodium can occur with vomiting, diarrhea, certain hormone conditions such as Addison's disease, or fluid buildup. Vets read sodium together with potassium and chloride.
What is Sodium?
Sodium is the main electrolyte outside cells and drives water balance.
Reference range
[Range pending sourced table] Reference ranges vary by lab and species. Use the range printed on your pet's report.
What can raise Sodium
- Dehydration
- Limited water access
- Some hormone conditions
What can lower Sodium
- Vomiting or diarrhea
- Addison's disease
- Fluid buildup
- Some kidney conditions
Dogs vs cats
In dogs
A low sodium-to-potassium ratio in dogs can prompt testing for Addison's disease.
In cats
Cats may hide dehydration, which can show as higher sodium.
Why one value rarely tells the whole story
Sodium reflects water balance as much as salt itself. Hydration, recent meals, stress during the visit, medications, and how the sample was handled can all shift a result. Vets look at the whole panel, your pet's symptoms, and the trend across tests over time.
Conventional interpretation
Vets read sodium with potassium, chloride, and hydration status.
Whole-pet context
Track water intake, vomiting, and diarrhea.
Supportive options are not a cure. Check with your veterinarian before adding any supplement.
Questions to ask your vet
- Is my pet dehydrated?
- What is the sodium-to-potassium ratio?
- How does this compare with my pet's previous results?
Frequently asked questions
Does high sodium mean too much salt in the diet?
- Usually it reflects water loss rather than diet.
Why does the sodium-to-potassium ratio matter?
- A low ratio can suggest Addison's disease, which vets test for specifically.
What is a normal Sodium range?
- Reference ranges vary by laboratory, analyzer, and species. Use the range printed on your pet's report and ask your vet how your pet's result compares.
Should Sodium be rechecked?
- Your veterinarian decides based on how far from range the value is, your pet's symptoms, and other results. Trends over time are often more useful than one result.
Related lab values
Related guides
Educational support only. Not a diagnosis or substitute for veterinary care.
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