Today's Veterinary Practice

SEP-OCT 2015

Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.

Issue link: http://todaysveterinarypractice.epubxp.com/i/561362

Contents of this Issue

Navigation

Page 18 of 83

tvpjournal.com | September/October 2015 | TOday'S VeTerinary PracTice Feline STruViTe & calcium OxalaTe urOliThiaSiS Peer reviewed 17 nephroliths and ureteroliths (Figure 3). 13 Ultrasonography can also be used to document renal pelvic dilation (pyelectasia) (Figure 4) and ureteral dilation in cases of ureteral obstruction. • Double-contrast cystography: Affords increased sensitivity for detecting small or radiolucent uroliths (usually not necessary for calcium oxalate and struvite urolithiasis). • Intravenous urography and ultrasonography: May be used to detect radiolucent nephroliths and differentiate mineralized renal tissue from actual nephroliths. Intravenous urography can also be used to document ureteral obstruction. • Ultrasound-guided antegrade pyelography: To document ureteral obstruction (Figure 5). Cystoscopy Transurethral cystoscopy may be performed in both male (fexible scope) and female (rigid scope) cats for the diagnosis of cystoliths; however, general anesthesia is required. In female cats, holmium:YAG laser lithotripsy associated with cystoscopy may be used to noninvasively "break up" cystoliths and remove them from the bladder without surgery. Cystoscopy may also be used to obtain biopsy tissue from the lower urinary tract. Laboratory Findings Urine pH, crystalluria, and presence of urease- producing bacteria may aid in the presumptive identifcation of urolith type. Serum ionized calcium concentrations should be assessed in cases of suspected calcium oxalate uroliths to rule out hypercalcemia. Uroliths may be caused by a UTI (struvite) or may compromise normal host defense mechanisms and predispose cats (especially female cats) to UTI. Therefore, a urine culture should be routinely performed. Defnitive Diagnosis Defnitive diagnosis requires quantitative mineral analysis of uroliths that have been voided or recovered from the urinary tract. TREATMENT General principles for treatment of urethral calculi include relief of urethral obstruction and bladder decompression, if necessary, which can usually be accomplished by: • Passage of a small-bore catheter • Cystocentesis • Dislodgment of urethral calculi by hydropropulsion. Fluid therapy should be initiated to restore water and electrolyte balance, if postrenal azotemia exists. Surgical Therapy Surgical intervention for calcium oxalate nephroliths (beyond dietary treatment—see Calcium Oxalate Uroliths, page 19—to help slow urolith growth) is usually not recommended. Similarly, surgical intervention of ureteral uroliths is usually not FIGURE 3. Ultrasound image of dilated ureter with ureterolith. FIGURE 4. Ultrasound image of dilated renal pelvis (pyelectasia) associated with ureteral obstruction. FIGURE 5. Positive contrast antegrade pyelogram demonstrating pyelectasia and ureteral obstruction due to a ureterolith.

Articles in this issue

Links on this page

Archives of this issue

view archives of Today's Veterinary Practice - SEP-OCT 2015