ABSTRACT. A 10-year-old male Korean domestic short-haired cat was presented with refractory lower urinary tract obstruction. The cat was treated by urethral stent placement using a self-expanding nitinol intraluminal stent (Zilver ® 535 biliary stents, COOK ® , U.S.A.) subsequent with balloon expansion. Although the cat showed 2 days of transient hematuria after the stent placement, no further obstruction was occurred after the stent placement. Follow-up studies performed at monthly intervals have found no re-stenosis or particular complications, to date.KEY WORDS: feline, FLUTD, FUS, urethral obstruction, urethral stent.J. Vet. Med. Sci. 71(9): 1255-1259, 2009 Lower urinary tract disease (LUTD) in cats has numerous causes including infection, trauma, urolithiasis, urethral obstruction or neoplasia [1]. Unlike dogs however, the most frequent cause for haematuria and dysuria in cats is unknown. This has led to numerous terms such as feline urologic syndrome (FUS), feline interstitial cystitis (FIC; based on similarities with the human condition) and idiopathic feline lower urinary tract disease (iFLUTD) [8,16]. It is reported that 70% of non-obstructive LUTD is idiopathic and that 25% is due to cystoliths [6]. Obstructive causes of LUTD are usually intraluminal with the majority caused by urethral plugs rather than uroliths. Urethral plugs have large amounts of matrix and minerals (usually struvite) and any crystalline material is disorganized. The general features of urolithiasis are similar for cats and dogs although struvite uroliths in cats are less associated with bacterial infections [6,7].Although the successful treatment of iFLUTD is often achieved with the removal of dry diets, stress reduction and increased water supply after re-canalization with indwelling urethral catheterization and warm saline flushing [5,7]. However, iFLUTD often re-occurs and progresses to refractory iFLUTD, which requires perineal urethrostomy to permanently relieve recurrent obstructions in male cats [5,7]. However, there can be post-operative problems such as stricture, recurrent urinary tract infections and perineal hernias [8,16].Urethral stent placement using self-expanding metallic stents under fluoroscopic guidance is widely used in humans and dogs with urethral obstructions secondary to transitional and prostatic tumors [9,[12][13][14]. This technique has several advantages over conventional surgical methods, because it can be used to rapidly, safely, and effectively relieve urethral obstructions, especially in patients in which other traditional techniques have failed, are not available, or not indicated [18]. These techniques are minimally invasive and can therefore lead to reduced peri-operative morbidity and mortality, shorter anesthesia times and shorter hospital stays, although the expense for urethral stent placement is substantial. This case report described the clinical application of urethral stent in a cat with refractory urethral obstruction.A 10-year-old male Korean domestic short-haired cat (3.9 kg of body w...