Objectives

In this study it was evaluated the hydro-saline balance of healthy dogs and in dogs with naturally acquired chronic renal failure (CRF).

Material & Methods

In order to classify the animals as normal or ill, they were followed up at least for three months and the evaluations included physical examination, serum chemical profile, urinalysis and creatinine clearance. The balance evaluations were performed for 30 consecutive days. The animals were logged in metabolic cages and the study began after an adaptation period. Animals showing necessity of supportive therapy was excluded.

Results

The results showed differences in water and sodium balance and homeostasis considering male versus female and healthy versus CRF dogs. Animals having CRF, in clinical stable condition, showed a tendency to lose sodium from the body reserves with no changes in water balance neither in serum effective osmolality. Negative sodium balance was detected in CRF females.

Conclusions

In dogs, the sodium and water balance are influenced by gender. The CRF changes the body sodium homeostasis, causing sodium loss that is more severe in females. Studies focusing sodium requirements and balance, in health and disease, must consider these facts.

This work was supported by FAPESP and CNPq-Brazil.