Exotis ISSN 2398-2985

Guinea Pigs

Polydipsia/polyuria

Synonym(s): PD/PU

Contributor(s): Cathy Johnson-Delaney, Anna Meredith

Introduction

  • Cause:
    • Primary polyuria: upper/lower urinary tract disease, hepatic failure, hypokalemia, osmotic diuresis that occurs with diabetes mellitus, ingestion of nephrotoxic plants.
    • Iatrogenic: administration of nephrotoxic drugs, corticosteroids, anticonvulsants, alcohol. Hyperthyroidism, diabetes insipidus, traumatic, neoplastic.
    • Primary polydipsia: psychogenic drinking, organic disease of the anterior hypothalamic thirst center due to neoplasia or trauma.
  • Signs: polyuria, polydipsia; may be additional clinical signs depending on underlying disease.
  • Diagnosis: CBC and serum biochemistries, urinalysis, radiography, ultrasonography.
  • Treatment: depends on etiology. If urolithiasis, obstruction will require supportive care and surgery, as well as post-operative management. Water should be available at all times. If dehydration, electrolyte imbalance corrections, fluid therapy may be needed. If anorexia provide assisted feeding.
  • Prognosis: depends on etiology.

Pathogenesis

Etiology

Primary polyuria

  • Upper urinary tract disease (renal failure, pyelonephritis).
  • Lower urinary tract disease (infection, urolithiasis, neoplasia, anatomic or neurologic problem).
  • Cystitis Cystitis/urolithiasis Urolithiasis.
  • Pyometra Pyometra and endometrial disorders.
  • Hepatic failure.
  • Hypokalemia.
  • Osmotic diuresis that occurs with diabetes mellitus, post obstructive diuresis, ingestion or administration of large quantities of solute containing sodium chloride, glucose.
  • Ingestion of nephrotoxic plants like lilies.
  • Iatrogenic: administration of nephrotoxic drugs (aminoglycosides, diuretics (furosemide, mannitol), corticosteroids, anticonvulsants (phenytoin), alcohol.
  • Hyperthyroidism Hyperthyroidism.
  • Diabetes insipidus - central, renal.
  • Traumatic, neoplastic.

Primary polydipsia

  • Psychogenic drinking - behavioral problems including boredom, pyrexia, pain.
  • Organic disease of the anterior hypothalamic thirst center due to neoplasia or trauma.
In other species consider inflammatory disease in the brain but this is not documented in guinea pigs.

Predisposing factors

General

Specific

  • Underlying disease such as renal failure, systemic infection causing pyrexia.
  • Administration of corticosteroids, nephrotoxic drugs (aminoglycosides), diuretics, anticonvulsants.

Pathophysiology

  • Average daily water consumption in guinea pigs: 10-15 mL/100 g BW/day. If fed a lot of high-moisture leafy vegetables will drink less than those on hay and pellets.
  • Urine production for rodents is calculated at 3.3-4.2 mL/100 g BW/day.
  • Urine production and water consumption are regulated by the hypothalamus, pituitary gland, and kidneys.
  • Polydipsia is usually a response to polyuria to maintain normal circulating body fluid volume. Hypertonic plasma activates the thirst mechanism.
  • Polyuria can occur as a response to polydipsia, although this is not as common. Plasma is hypotonic due to excessive water intake and anti-diuretic hormone (ADH) secretion.

Timecourse

  • Depends on etiology.
  • PU/PD due to obstruction (urolithiasis Urolithiasis) may be acute.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Hawkins M G (2006) Diagnostic evaluation of urinary tract calculi in guinea pigs. Exot DVM 8 (3), 43-47.

Other sources of information

  • Hawkins M G & Bishop C R (2012) Disease Problems of Guinea Pigs. In: Ferrets, Rabbits, and Rodents Clinical Medicine and Surgery. 3rd edn. Eds: Quesenberry K E & Carpenter J W. Elsevier. pp 295-310.
  • Hawkins M G (2011) Polyuria and polydipsia. In: Blackwell's Five-Minute Veterinary Consult: Small Mammal. Ed: Oglesbee B L. Wiley-Blackwell. p 314-316.


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