Background: Most dogs with primary hypoadrenocorticism (HA) have a mineralocorticoid deficiency, which decreases renal tubular sodium reabsorption and potassium excretion. Limited information is available concerning the clinical value of measuring urine electrolytes to aid in an HA diagnosis. Objectives:We aimed to evaluate the diagnostic utility of urine electrolyte measurements in dogs with HA.Methods: Urine sodium and potassium concentrations were measured in 89 dogs, including 39 dogs with HA and 50 controls with nonadrenal illness. Fractional excretions of sodium (FE Na ) and potassium (FE K ) were also calculated. Urine electrolytes and fractional excretion values were compared between the groups. Sensitivities and specificities were determined for various cut-points. Results:The median urine sodium to potassium (Na:K) ratio was twofold greater (P < .001), and median FE Na was fourfold greater (P < .001) in HA dogs as compared with controls. However, no cut-point for any variable with >90% sensitivity or specificity provided a corresponding specificity or sensitivity of >50%. When only dogs with abnormal serum or plasma electrolytes were included in the analyses, absolute urine electrolyte concentrations and FE Na were not different between study populations (P > .05 for all comparisons), but the FE K was increased (P = .005) and the urine potassium:creatinine ratio was decreased (P < .001) in the control dogs compared with the dogs with HA.Conclusions: Urine electrolyte concentrations and fractional excretions are altered in dogs with HA. However, substantial overlap exists with control dogs with nonadrenal illness. Therefore, these values are unlikely to have diagnostic utility for dogs with HA.

Case series summary Seven cats were found to have postoperative subcutaneous ureteral bypass (SUB) occlusion secondary to blood clot formation. An increase in serum creatinine led to imaging and clot detection in all but one case. Alteplase, a tissue plasminogen activator, was infused into the SUB via the port in four cats, intravesicularly via a transurethral urinary catheter in one cat, and by both routes in two cats. Patency of the SUB was re-established in all cats within 2 days. No short- or long-term complications directly attributed to alteplase administration were observed. Relevance and novel information The results of this case series suggest that alteplase infusion via either the SUB port and/or a transurethral catheter should be considered prior to surgical intervention for the treatment of postoperative SUB occlusion secondary to a blood clot.

OBJECTIVE To determine if urine electrolyte assessments can be used to monitor the adequacy of mineralocorticoid therapy in dogs with hypoadrenocorticism (HA). ANIMALS 29 dogs with naturally occurring glucocorticoid- and mineralocorticoid-deficient HA. PROCEDURES Urine sodium and potassium concentrations, sodium-to-potassium ratios, sodium-to-creatinine ratios, and potassium-to-creatinine (K:Cr) ratios were evaluated in dogs with newly diagnosed HA that were treated with desoxycorticosterone pivalate (DOCP). Dogs underwent measurements of urine and serum sodium, potassium, and creatinine concentrations and plasma renin activities twice monthly for up to 3 months. Regression analyses and calculation of coefficients of determination (R2) were performed to investigate potential associations between urine and serum variables. Urine variables also were compared between dogs considered to be undertreated or overtreated based on plasma renin activities. RESULTS Urine K:Cr ratios were significantly associated with serum potassium concentrations 10 to 14 days (P = .002) and 30 days (P = .027) after the initial DOCP injection, but R2 values were only 0.35 and 0.17, respectively. Urine K:Cr ratios (median [IQR]) also were higher in dogs that were overtreated with DOCP (1.3 [0.7 to 2.3]) as compared to those dogs that were undertreated with DOCP (0.8 [0.5 to 0.9]) at 10 to 14 days after the initial DOCP injection (P = .039) but not at 30 days after the initial injection. Other urine variables were not significantly different between undertreated and overtreated dogs. CLINICAL RELEVANCE Measures of urine electrolytes were not useful for assessing the adequacy of mineralocorticoid therapy in HA dogs that were treated with DOCP.