ABSTRACT
BACKGROUND: Lowering the dose of desoxycorticosterone pivalate (DOCP) for the treatment of dogs with primary hypoadrenocorticism (PH) decreases costs and could lead to increased owner motivation to treat their affected dogs. OBJECTIVE: To evaluate the efficacy of a low-dose DOCP treatment protocol in dogs with PH. ANIMALS: Prospective study, 17 client-owned dogs with naturally occurring PH (12 newly diagnosed, 5 previously treated with fludrocortisone acetate [FC]). METHODS: Dogs with newly diagnosed PH were started on 1.5 mg/kg DOCP SC; dogs previously treated with FC were started on 1.0-1.8 mg/kg DOCP SC. Reevaluations took place at regular intervals for a minimum of 3 months and included clinical examination and determination of serum sodium and potassium concentrations. The DOCP dosage was adjusted to obtain an injection interval of 28-30 days and to keep serum electrolyte concentrations within the reference interval. RESULTS: Median (range) follow-up was 16.2 months (4.5-32.3 months). The starting dosage was sufficient in all but 2 dogs and had to be significantly decreased after 2-3 months to a median dosage (range) of 1.1 mg/kg (0.7-1.8). Dogs 3 years of age or younger needed significantly higher dosages compared to older dogs. None of them, however, needed the 2.2 mg/kg DOCP dosage, recommended by the manufacturer. CONCLUSIONS AND CLINICAL IMPORTANCE: A starting dosage of 1.5 mg/kg DOCP is effective in controlling clinical signs and serum electrolyte concentrations in the majority of dogs with PH. An additional dose reduction often is needed to maintain an injection interval of 28-30 days. Young and growing animals seem to need higher dosages.
Subject(s)
Addison Disease/veterinary , Desoxycorticosterone/analogs & derivatives , Dog Diseases/drug therapy , Mineralocorticoids/administration & dosage , Addison Disease/drug therapy , Addison Disease/economics , Age Factors , Animals , Desoxycorticosterone/administration & dosage , Desoxycorticosterone/economics , Desoxycorticosterone/therapeutic use , Dog Diseases/economics , Dogs , Female , Male , Mineralocorticoids/economics , Mineralocorticoids/therapeutic use , Potassium/blood , Prospective Studies , Sodium/bloodABSTRACT
BACKGROUND AND PURPOSE: Vascular endothelial growth factor (VEGF), a specific pro-angiogenic factor is proposed to be involved in cancer progression and resistance to radiation therapy by promoting angiogenesis and by protecting endothelial cells from radiation induced apoptosis. The aim of this study, was first to assess the influence of ionizing radiation on plasma VEGF concentration in spontaneous canine tumors during fractionated radiation therapy with curative or palliative intent and second to analyze plasma VEGF concentration as predictor for treatment outcome. PATIENTS AND METHODS: For plasma VEGF analysis a human VEGF enzyme linked immunosorbent assay was used. Sixty dogs with various tumor types were included in this study. Dogs were irradiated with either low dose per fx (3-3.5 Gy per fraction, total dose: 42-49 Gy, group A: curative intent) or high dose per fx (6-8 Gy per fraction, total dose: 24-30 Gy, group B: palliative intent). Blood samples were taken before and after dose application at certain time points during therapy. Follow-up evaluation was performed for analysis of time to treatment failure and survival. RESULTS: Repeated measures analysis showed no increase of plasma VEGF in dogs treated with fractionated radiation therapy (group A and B). Dichotomizing baseline plasma VEGF into two groups with high and low plasma VEGF, resulted in shorter time to treatment failure in dogs with high plasma VEGF levels (TTF, group A: P=0.038, group B: P=0.041). CONCLUSIONS: This study demonstrated that dogs with a plasma VEGF level higher than 5 pg/ml had a poorer outcome after radiation therapy. It is therefore, suggested, to use plasma VEGF as predictor for treatment outcome in radiation therapy.
