Larry G. Adams, DVM, PhD, DACVIM

In dogs, leptospirosis most commonly results in acute renal failure (ARF) with or without concurrent (or subsequent) hepatic disease. Although leptospirosis can cause ARF along with acute liver disease (or liver failure), ARF without liver disease has become the most common clinical presentation of the predominant serovars of leptospirosis affecting dogs in the US.

Diagnosis and management of the majority of cases are routine; however, treatment of refractory urinary incontinence cases are frustrating for both the veterinarian and owner. The diagnostic approach to dogs with refractory urinary incontinence should include a thorough history (drugs, age of onset, and timing during the day of incontinence), physical examination (including rectal and neurologic examination), serum biochemistry profile, urinalysis, urine culture, abdominal radiographs and ultrasonography.

Recurrent urinary tract infections (UTI) are a common problem in dogs. There are 2 major types of UTI recurrence: relapse and reinfection. The implications of relapse versus reinfection are important for diagnosis and management of recurrent UTI. Relapses are defined as UTI recurrence of the same species and serologic strain of microorganisms within several weeks of withdrawal of therapy.

Nephroliths are uroliths (calculi) located in the renal pelvis and/or collecting diverticula of the kidney and ureteroliths are calculi located in the ureter. Although only 5 to 7% of all feline uroliths submitted to stone centers for analysis are nephroliths, the true incidence of nephroliths may be higher because many animals with nephroliths are asymptomatic.

Chronic kidney disease (CKD) is the term used to replace the older terms of chronic renal failure and renal insufficiency. This recognizes that CKD has a spectrum of severity from asymptomatic kidney disease to end stage uremia. Although CKD tends to be stable over the short term, it tends to progress to end-stage renal failure over months to years in most animals with CKD.

One of the common clinical scenarios that may present a diagnostic challenge is dogs or cats with urine retention without an obvious cause. The fundamental question in these cases is: "Does this patient have functional urinary retention or mechanical urinary obstruction?"

The most common cause of feline lower urinary tract disease is idiopathic cystitis. Feline idiopathic cystitis, formerly called idiopathic feline lower urinary tract disease, is defined as a disease of undetermined etiology characterized by hematuria, dysuria, pollakiuria and possible urethral plug formation.