The correlation between the severity of thyroid dysfunction and renal function has been documented in humans with normal renal function. Together with the decreased cardiac output that occurs in hypothyroidism, 6 these processes lead to decreased GFR and increased serum creatinine concentration in experimental animals and humans.

Intrarenal vasoconstriction, 4 decreased response to vasodilators in the kidney, 1 and decreased activity of the renin-angiotensin-aldosterone-system (RAAS) 5 all cause decreases in RBF. 3 Most effects of hypothyroidism on kidney function are opposite those caused by hyperthyroidism. Hyperthyroidism increases the rate of several physiologic processes, which is reflected in decreased systemic vascular resistance, increased cardiac output and increased RBF, 1 hypertrophic and hyperplastic tubules, 2 and increased GFR. 1- 7 These changes in kidney function are mediated indirectly by effects on the cardiovascular system and renal blood flow (RBF) and directly by effects on glomerular filtration rate (GFR), tubular secretory and absorptive capacities, and the structure of the kidney. Hyper and hypothyroidism are known to alter kidney function in humans and experimental animals other than dogs.

area under serum concentration versus time curve.

Re-establishment of a euthyroid state increased GFR significantly. 01).Ĭonclusion: GFR was <2 mL/min/kg in untreated hypothyroid dogs. GFR increased significantly with levothyroxine supplementation the corresponding results were 1.6 ± 0.4 mL/min/kg at T0, 2.1 ± 0.4 at T1, and 2.0 ± 0.4 at T6 ( P <. All dogs remained normotensive throughout the study. Their average body weight decreased from 35 ± 18 kg at T0 to 27 ± 14 kg at T6 ( P <.

Results: At T0, the average age of dogs in the study group was 6.3 ± 1.4 years. Results are expressed as mean ± standard deviation. Statistical analysis was performed using a general linear model. If needed, levothyroxine dosage was adjusted and reassessed after 1 month. The response to therapy was monitored at T1 by measuring serum total thyroxine and thyroid stimulating hormone concentrations. Methods: Blood pressure and GFR (measured by exogenous creatinine clearance) were measured before treatment (T0, n = 14) and at 1 month (T1, n = 14) and at 6 months (T6, n = 11) after beginning levothyroxine supplementation therapy (20 μg/kg/d, PO). The objective of this study was to assess GFR in hypothyroid dogs before implementation of thyroxine supplementation and after re-establishing euthyroidism.Īnimals: Fourteen hypothyroid dogs without abnormalities on renal ultrasound examination or urinalysis. Hypothesis: Hypothyroidism influences GFR in dogs. Background: Glomerular filtration rate (GFR) is decreased in humans with hypothyroidism, but information about kidney function in dogs with hypothyroidism is lacking.

Dog pica kidney disease