Bilateral xanthine nephrolithiasis in a dog

Xanthinuria is an uncommon metabolic disorder clinically manifested as urolithiasis. There are two forms of the disease, congenital and iatrogenic. The former was diagnosed in a four-year-old dachshund bitch. The patient was presented with signs of terminal chronic renal failure. Urine was bacteriologically sterile with massive amorphous crystalluria. Bilateral nephrolithiasis was diagnosed at necropsy. The kidneys were shrunken with marked atrophy of the renal cortex and medulla. Infrared spectrometry revealed that the stones comprised 100 per cent xanthine. Later, two of the patient's siblings were examined for urine xanthine content; both showed higher concentrations of xanthine than a control dog. The described case is compared with seven known published cases of congenital xanthinuria.

[Drug-induced urolithiasis caused by N4-acetylsulfamethoxazole (Biseptol) and oxolinic acid (Desurol)]

The authors describe rare types of drug-induced urolithiasis in two female patients (N4-acetylsulfamethoxazole--a Biseptol metabolite and oxolinic acid--Desurol). To improve the diagnosis of drug induced urolithiasis the authors recommend a combination of microscopic methods and infrared spectroscopy. They findings are documented by photographs and infrared absorption spectra.

[Personal experience with infrared spectrometry analysis of urinary calculi]

Analysis of urinary concrements has a very important place in clinical biochemistry departments, as it is one of the basic prerequisites for effective causal therapy and prophylaxis of nephrolithiasis. Qualitative chemical reactions, used most frequently, have shortcomings as regards the identification of components of calculi and do not provide a real idea on the composition of calculi (9). An accurate identification can be made only by physical methods, which, however, call for very expensive equipment. Clinical departments in Prague, Brno and Ostrava collaborate therefore with research institutes which possess the necessary equipment and where the analyses of calculi are made. Because the majority of clinical biochemical departments have limited access to modern infrared computer controlled spectrometers, this form of collaboration was used also in the authors' department.