Hyponatremia

From Dog

Hyponatremia is defined as a blood sodium level <135 mEq/L (normal is 140 - 165).

Body stores of sodium and potassium are intimately related and maintained by balanced intake and excretion, intracellular and extracellular osmotic pressure, and pH[1]. Hyonatremia is commonly associated with hyperkalemia[2].

Sodium-potassium (Na:K) ratio has frequently been used as a diagnostic tool to identify adrenal insufficiency.

The normal Na:K ratios in dogs range from 27:1 to 40:1, while the values in canine hypoadrenocorticism (Addison’s disease) are often below 27:1 and may be below 20:1 in primary hypoadrenocorticism, characterized by hyponatremia, hypochloremia and hyperkalemia[3].

Other disorders which can cause hyponatremia include:

Clinically affected dogs present with dehydration, lethargy, myalgia, cramping and reluctance to walk.

Parenteral electrolyte replacements are usually sufficient to correct hyponatremia.

References

  1. Brobst, D (1986) Review of the pathophysiology of alterations in potassium homeostasis. J Am Vet Med Assoc 188:1019-1025
  2. DiBartola, SP et al (1985) Clinicopathologic findings resembling hypoadrenocortisim in dogs with primary gastrointestinal disease. J Am Vet Med Assoc 187:60-63
  3. Feldman, EC & Nelson, RW (1996) Canine and feline endocrinology and reproduction. pp:266-281, 2nd ed. WB Saunders, Philadelphia, 1996
  4. Hutchinson D et al (2012) Seizures and severe nutrient deficiencies in a puppy fed a homemade diet. J Am Vet Med Assoc 241(4):477-483
  5. Pak SI (2000) The clinical implication of sodium-potassium ratios in dogs. J Vet Sci 1(1):61-65
  6. Aroch I et al (2005) Clinical, biochemical, and hematological characteristics, disease prevalence, and prognosis of dogs presenting with neutrophil cytoplasmic toxicity. J Vet Intern Med 19(1):64-73
  7. Dell'Orco M et al (2009) What is your diagnosis? Peritoneal effusion from a dog. Vet Clin Pathol 38(3):367-369
  8. Ghali JK et al (2010) Lixivaptan, a non-peptide vasopressin V2 receptor antagonist for the potential oral treatment of hyponatremia. IDrugs 13(11):782-792
  9. Kang MH & Park HM (2012) Syndrome of inappropriate antidiuretic hormone secretion concurrent with liver disease in a dog. J Vet Med Sci 74(5):645-649
  10. Shiel RE et al (2009) Syndrome of inappropriate antidiuretic hormone secretion associated with congenital hydrocephalus in a dog. J Am Anim Hosp Assoc 45(5):249-252
  11. Boag AK et al (2005) Acid-base and electrolyte abnormalities in dogs with gastrointestinal foreign bodies. J Vet Intern Med 19(6):816-821
  12. Boisvert AM et al (1999) Artifactual effects of hypernatremia and hyponatremia on red cell analytes measured by the Bayer H*1 analyzer. Vet Clin Pathol 28(3):91-96