Effective long-term management of urolithiasis depends on identification and manipulation of factors contributing to initial stone formation; identification of these factors depends on accurate identification of the mineral composition of the urolith involved. The purpose of this study was to determine the chemical composition of uroliths obtained from the low urinary tract of dogs in Mexico City. One hundred and five cases of urolithiasis were studied in which stones were surgically obtained from the low urinary tracts of dogs treated in different hospitals. The chemical composition of the uroliths was quantitatively and qualitatively determined by stereoscopic microscopy, IR-spectroscopy, scanning electron microscopy and X-ray microanalysis. Age of animals ranged from 4 months to 14 years, with a median of 5 years. Composition and distribution of the uroliths were struvite 38.1%, calcium oxalate 26.7%, silica 13.3%, urate 7.6%, mixed 11.4%, compounds 1.9%, and cystine 1%. Most uroliths were found in pure breed dogs (75.2%); 23 different breeds were identified, and more than half of the submissions were from breeds of small size. In our study, the frequency of struvite, calcium oxalate, cystine, urates, mixed and compounds stones are in agreement with papers that report on dog populations in America and Europe, but a higher frequency of silica uroliths was observed in Mexico City dogs.

We describe a simple and feasible procedure for performing intravenous administration of substances in the gerbil. Under light anaesthesia, animals were held in dorsal recumbency and a very small incision of skin, parallel to the femoral vein on the internal side of the thigh, was made. The vein is easily accessible via thin skin incision. An insulin syringe and a 30 G needle were used for the injection. This is an easy and quick method, which, with appropriate anaesthesia, allows rapid recovery.

-Twenty-four hour urinary excretion, fractional excretion and the filtered load of calcium and phosphorus were monitored as hyperparathyroidism evolved in a model of progressive canine renal failure. Thirteen beagles of both sexes aged four and a half months were used. Nine of them were subjected to a renal damaging schedule (neomycine, 60 mg/kg/48 h, IM, 32 weeks) in order to induce chronic renal failure leading to secondary hyperparathyroidism (2HPT group). The remaining four were kept as the control group. The experiment was conducted over 32 weeks. Blood and 24 h urine were collected every four weeks. Calcium, phosphorus and creatinine were analyzed. Plasma parathormone and calcitonin were determined at weeks 0, 12, 24 and 32. The level of renal function in the 2HPT animals was reduced to 25% of that of the controls (endogenous creatinine clearance was 0.45 ± 0.22 mL/min/kg as opposed to 1.81 ± 0.54 mL/min/kg). Hyperparathyroidism was confirmed by a progressive increase in the levels of the parathyroid hormone. Calcitonin levels were not modified. A tendency to hypocalcaemia was observed, reaching statistically significant levels from the twenty-eighth week of the study, when hyperphosphataemia also became significant. Daily urinary excretion of calcium and phosphorus remained at values considered normal throughout the experiment with no alteration imputable to the impaired renal function. This is explained by the decrease in the filtered load of these elements (in both cases statistically significant from the 24th week on) being associated with an increase in their fractional excretion. Thus, calcium and phosphorus urinary excretion values could be maintained in a normal range up to the end of the experiment, showing that renal calcium handling in dogs with experimentally induced renal failure seems to differ from that observed in human patients. renal hyperparathyroidism / calciuria / phosphaturia / parathyroid hormone / calcitonin / dog

The congenital heart disease identified in this beagle family can be classified as conotruncal malformation, and an autosomal recessive mode of inheritance was suggested by pedigree analysis.

A 10-month-old female domestic shorthaired (DSH) cat was presented with peracute respiratory problems. Physical examination revealed dyspnoea, tachypnoea, cyanosis, weak pulse and bradycardia. Auscultation showed pulmonary crepitation and attenuated heart sounds and a pansystolic grade V/VI murmur. The electrocardiogram showed atrioventricular dissociation identified as third-degree sinoatrial block. X-rays showed increased density in the ventral and middle zones of the thorax and loss of definition of the cardiac silhouette and increased diffuse radiographic density of the entire abdomen.Echocardiography revealed dilatation of the right atrium and concentric biventricular hypertrophy. A type 1 persistent truncus arteriosus was diagnosed at necropsy. This is the first case report of this type of arrhythmia in a cat with persistent truncus arteriosus, and its relationship with the described congenital cardiac anomaly is discussed.