Diagnostic approach to lower urinary tract disease (Proceedings)
The clinical signs of many lower urinary tract diseases (LUTD) in dogs and cats are similar. Correct identification of the underlying disease process is critical to the development and implementation of a successful treatment plan. The diagnostic approach to dogs and cats with lower urinary tract signs should depend on the pet's age and signalment, history and severity of clinical signs.
When assessing a patient with lower urinary tract disease, the signalment may be very helpful in narrowing the list of possible etiologies. For example, younger cats are more likely to have idiopathic lower urinary tract disease, while this disease occurs much less commonly in cats greater than 10 years of age. Sex is important in that female patients are more likely to have bacterial urinary tract infections, etc. Knowledge of breed predispositions to specific lower urinary tract disease will also help to focus diagnostic efforts. For example, Bichon's are predisposed to developing calcium oxalate stones, male Dalmatian's are predisposed to developing urate stones, and older Scottish terriers have a predisposition for transitional cell carcinoma of the bladder.
A complete and detailed history from the owner is very important in establishing a diagnosis. Along with the chief complaint, it is imperative to obtain information about the past and present history, including environment and diet. Specific questions should focus on the patients' general attitude and activity level, water consumption, frequency and pattern of urination, abnormalities in the smell or colour of the urine, any other system abnormalities. Additionally, information about all previous treatments and response to therapy should be obtained. Common presenting complaints of patients with lower urinary tract disease include stranguria, pollakiuria, hematuria, and inappropriate urination. Although inappropriate urination may be a behavioural issue, especially in cats, this should be a diagnosis of exclusion and all medical causes should be investigated.A thorough physical exam, including visual inspection of the external genitalia may also be helpful in localizing the problem. Perineal dermatitis and/or wetness could indicate urinary incontinence. Abdominal palpation may be used to assess bladder size and turgor. Palpation of the abdomen may also be helpful in identifying pain. Transrectal palpation of the urethra can be used to detect urethroliths, urethral tumors, urethral tone, and prostatic disease, all of which can contribute to lower urinary tract signs.
The typical initial minimum database for any patient presenting for lower urinary tract signs includes a detailed history, physical exam, urinalysis, urine culture and survey abdominal radiography. More extensive laboratory evaluations including complete blood count and serum chemistry panel should be considered for older animals or patients with comorbid conditions. Additional diagnostic testing such as ultrasound, contrast radiography, or cystoscopy should be considered in patients with persistent or chronic signs or in those that have not had the expected clinical response to previous therapies.