Xanthinuria in a domestic shorthair cat

Abstract

| the VETERINARY RECORD SHORT COMMUNICATIONS catheter connected to a closed urine collection system. Routine blood work, including a complete blood count and serum chemistry profile, was unremarkable. Urinalysis revealed crystals suspected to be xanthine, and an inactive sediment. Plasma and 24-hour urine samples were submitted for xanthine and hypoxanthine measurements using HPLC and UV detection (Agilent 1000 series; Agilent Technologies), and 24-hour urine was submitted for uric acid measurements using a commercial enzymatic test (Roche Diagnostics) in an automatic analyser (Roche/ Hitachi Modular P800).Twenty-four-hour urine collection was subsequently performed in three unrelated male cats (control cats) that were presented for obstructive FLUTD not associated with crystalluria. The affected cat and the three controls were fed a regular adult moist maintenance diet before presentation and a diet for urinary tract disease (Feline Urinary Moist food; Royal Canin) during the time of sample collection. The plasma and urine xanthine and hypoxanthine levels were markedly higher, and urine uric acid levels were markedly lower, in the case than in the control cats ( Table 1). The urine xanthine:creatinine and hypoxanthine:creatinine ratios were higher, and the urine uric acid:creatinine ratio was lower, than in the three control cats (Table 1). These results are consistent with a lack of conversion of xanthine to uric acid, as would occur with a deficiency in xanthine oxidase, leading to xanthinuria.A perineal urethrostomy was performed and the cat made an uneventful recovery from the surgical procedure. It was treated with 0·01 mg/kg buprenorphine (Temegesic; Essex Chemie) intravenously every six hours for four days, 2·5 mg phenoxybenzamine (Phenoxybenzamin; Streuli) orally every 12 hours for three days, and 10 mg/kg amoxicillin and 2·5 mg/kg clavulanic acid (Clavaseptin; Vétoquinol) orally every 12 hours for 14 days.Five days after surgery, the cat was urinating without difficulty and was discharged from hospital in good general condition. A physical examin ation 11 months after surgery was unremarkable, and the cat continued to urinate without difficulty. It was still fed with regular commercial feline moist foods due to poor compliance with purine-restricted diets. A complete blood count was unremarkable and serum chemistry revealed mild azotaemia (urea 16·8 mmol/l, reference range 6·7 to 12·5 mmol/l; creatinine 185 µmol/l, reference range 53 to 141 µmol/l). Urinalysis revealed a specific gravity of 1·027, and an inactive sediment with very large numbers of yellow-brown spheroid crystals of varying size, resembling ammonium urates or amorphous urates (Fig 1). Urine bacterial culture revealed no growth. An abdominal ultrasound examination revealed small kidneys with mildly hypoechogenic cortices and suspected renal pelvic urolithiasis. Blood and urine spot samples were again analysed for purine concentrations. Xanthine and hypoxanthine were again markedly higher, and urine uric acid was again markedly lower, than...

Hereditary xanthinuria and urolithiasis in a domestic shorthair cat

“…This report describes a young adult castrated DSH cat with xanthinuria similar to 5 previously described cats (White 1997; Tsuchida 2007; Schweighauser 2009; Mestrinho 2013). A diagnosis of hereditary xanthinuria was suspected based upon the urinary crystal morphology and confirmed by analyses showing calculinmade up of 100% xanthine together with high urinary xanthine values.…”

“…In cats, xanthinuria (Online Mendelian Inheritance in Animals 001283-9685) was previously described in 5 domestic shorthair (DSH) cats (White 1997; Schweighauser 2009; Mestrinho 2013) and 1 Himalayan cat (Tsuchida 2007). Laboratories dealing with urolith analysis reported that 0.1–0.3% of feline calculi analyzed were composed of xanthine (Osborne 2004; Canon 2007; Hesse 2012).…”

Xanthine Nephrolithiasis in a Galician Blond Beef Calf

“…It is usually associated with the administration of allopurinol as part of the medical management for urate urolithiasis [6]. Naturally occurring xanthinuria has been reported only rarely in dogs, including a family of Cavalier King Charles [13] and Dachshunds [1,3], and in cats [9,12,15].…”

“…Definitive diagnosis of naturally occurring xanthinuria based upon plasma and urine uric acid concentrations are characteristically very low, xanthine high and low or no activity of the enzyme XDH [2,9,15]. Another possibility to confirm the disease is to examine the family line: siblings, sire and the dam, but unfortunately the dam had been slaughtered one week prior the calf was euthanized, and there were no siblings.…”

The effect of disease on the urinary purine metabolite concentrations in dogs

“…Uric acid: ­creatinine ratios in spot urine samples have been used to qualitatively identify hyperuricosuric dogs with a mutation of the urate transporter SLC2A9 (Karmi and others 2010) and these results were consistent with previous uric acid measurement via 24-hour urine collections (Bartges and others 1999). In a study of cats, concurrent xanthine and uric acid measurement in spot urine samples and 24-hour urine samples were positively correlated (Schweighauser and others 2009). …”