Association between systolic blood pressure and target organ damage in naturally occurring cases of systemic hypertension in the dog.

Chronic elevation in the systolic blood pressure (SBP) adversely affects the lifespan in the dog by causing injury to the eye, heart, kidney and brain. Understanding the association between SBP and target organ damage (TOD) helps in risk categorization and treatment planning. Therefore, a prospective study was undertaken to find the association between SBP and renal resistive index (RI) in naturally occurring cases of canine systemic hypertension. Based on the ACVIM guidelines 2018, dogs (n=135) were categorized into four risk groups of SBP, viz., A (minimal), B (low), C (moderate), and D (high). Ophthalmoscopy and echocardiography were used to assess ocular and cardiac changes, respectively. Nephrosonography, urinalysis, and RI were used to assess kidney damage. Odds ratio (OR) was used to quantify the risk of TOD for different categories of SBP. One-way Anova with Tukey's post-hoc test was used to test the effect of different SBP risk groups on urine protein creatinine ratio (UPC) and RI as well as the effect of number of TOD on the RI. Pearson's correlation test was done to see the relation of SBP with UPC and RI. Tortuous retinal vessels were common in group B with an OR of 11 (95% CI: 0.59-207). Retinal hemorrhage and left ventricular hypertrophy were common in group D with an OR of 13 (95% CI: 0.67-234) and 11 (95% CI: 0.61-207), respectively. A significant strong positive correlation of SBP with UPC (R2=0.65) and RI (R2=0.58) was observed. The renal RI significantly increased when the number of TOD was ≥ 2. It was concluded that SBP and RI are associated with the number and severity of TOD and might be valuable in risk classification in hypertensive dogs.

Abnormal renovascular resistance in dogs with diabetes mellitus: correlation with glycemic status and proteinuria.

Present study was conducted with the objectives of determining the renal vascular resistance in dogs with diabetes mellitus and to study the correlation between the indices of renovascular resistance with glycemic status, systolic blood pressure (SBP) and proteinuria in dogs with diabetes mellitus. This study was conducted on seventeen diabetic dogs and ten apparently healthy dogs. Increased renal resistive index (RI) and pulsatility index (PI) were observed in diabetic dogs as compared to healthy dogs. Systemic hypertension and proteinuria were observed in 10 and 3 out of 17 diabetic dogs, respectively. Significant positive correlation was observed between the indices of renovascular resistance and fasting blood glucose levels and between the indices of renovascular resistance and serum glycated hemoglobin levels. No correlation was observed between the indices of renovascular resistance and SBP as well as the indices of renovascular resistance and proteinuria. As the indices of renovascular resistance correlate significantly with glycemic status, they can be used as the early marker for kidney damage in diabetic patients. Among these indices renal PI was found to be more sensitive than renal RI.