Ovine pregnancy toxemia, a disease that affects adult ewes in the final stages of pregnancy and which is caused by a negative energy imbalance, requires the usage of dextrose substances for treatment. It has been proven that it is possible to induce reticular groove closure by means of an intravenous injection of lysine-vasopressin (LVP) at doses of 0.08 IU/kg B.W., which enables oral administration of glucose solutions that can be used in pregnancy toxemia therapy. The aim of this research is to compare the effectiveness of conventional treatment with i.v. glucose solution versus coadministration of LVP and a commercial sugar-water solution. This was administered orally to eight ewes to which we experimentally had provoked pregnancy toxemia by fasting. The use of commercial sugar, replacing other glucose solutions, could facilitate and cheapen the therapy for this disease significantly. The results obtained indicate that the joint administration of LVP and an oral solution of commercial sugar produce a noteworthy increase in glycaemia, which has a longer effect over time despite being less marked than with i.v. administration of glucose solution. Therefore, it could be used in the therapy of this disease. Besides, it is also able to normalize other parameters used to evaluate energy metabolism in ewes during the days of the trial.