Excess Sodium in the Blood in Cats

By PetMD Editorial on Mar. 28, 2010

Hypernatremia in Cats


Hypernatremia is the term used to denote abnormally high levels of sodium in blood. A vital electrolyte, sodium is involved in many critical bodily functions, including maintaining blood pressure, blood volume, maintain the delicate acid/base balance in the body, as well as play a role in the transmission of nerve impulses (signals) within nerves.


A common source of sodium is table salt (NaCl). Due to the presence of chloride (Cl) in NaCl, chloride derangements are commonly seen along with sodium.


If not treated quickly, hypernatremia can lead to severe consequences for the health of your cat.


Symptoms and Types


  • Increased thirst (polydipsia) and consumption of water
  • Confusion and disorientation
  • Coma
  • Seizures
  • Other symptoms may be related to underlying cause




  • Vomiting
  • Diarrhea
  • High water loss through urine (as seen with diabetes)
  • Intravenous fluid therapy containing NaCl
  • Lower water intake
  • High oral sodium intake (rare)




Your veterinarian will take a detailed history of your cat, including a history of any previous medical treatment. He or she will then perform a complete physical examination. Routine laboratory tests include: complete blood count, biochemistry profile, and urinalysis, which will reveal high levels of sodium along with other abnormalities. For cats with diabetes, urinalysis will reveal changes in urine, including low sodium levels. More specific testing for diagnosis of underlying diseases may need to be carried out.



Fluid therapy is commonly used to correct the electrolyte balance. In dehydrated cats, fluid therapy needs to be carried out over some time to correct fluid and electrolyte derangements. Your veterinarian will measure the sodium and other electrolyte levels during and after the treatment to ensure that levels of electrolytes are within normal ranges. Treatment of underlying causes (e.g., diabetes) is essential for complete resolution of the problem and to prevent future episodes.


Living and Management


Follow guidelines given by your cat’s veterinarian. Ensure continuous supply of water for those patients with diabetes. A sodium restricted diet may be suggested for your cat. Don’t give treats to your cat, especially those with sodium chloride, without discussing with your veterinarian. Stick with the diet recommended for your cat until complete recovery is achieved.


Most cats with hypernatremia without any underlying disease respond well and prognosis is excellent. However, animals with an underlying disease responsible for electrolyte derangements, prognosis depends on treatment of the disease along with correction of electrolyte imbalances.

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