A 12-year-old intact female Schnauzer was referred for the evaluation of poorly controlled diabetes mellitus: despite insulin therapy, blood glucose concentration was consistently high, indicating a decreased insulin sensitivity. Laboratory analyses revealed persistent hyperglycemia, glucosuria, and ketonuria. Diagnostic approaches were performed to identify concurrent disorders that can cause insulin resistance. The dog was found to have concurrent hyperadrenocorticism, hyperlipidemia, pancreatitis, and vaginal cytology indicating diestrus in the estrus cycle. Trilostane administration for hyperadrenocorticism improved the insulin response; however, the dog remained hyperglycemic. Eventually, the dog showed complete remission without insulin administration 1 week after the ovariohysterectomy. The dog remained in remission for approximately 4 months, but eventually relapsed and the condition was permanent. Diestrus in intact females and hyperadrenocorticism are known to be the two main causes of insulin resistance in dogs. After the management of these conditions, the dog achieved diabetes remission, which rarely achieves in dogs. In cases of insulin resistance, such as hormonal imbalances or inflammatory conditions, remission can be achieved by addressing the underlying cause. Hence, it is important to assess the presence of comorbidities associated with insulin resistance in dogs with poorly controlled diabetes mellitus and to treat each condition as soon as possible.

A 10-year-old spayed female Yorkshire Terrier visited for a physical checkup. The bitch had a history of ovariohysterectomy for treatment of pyometra a year ago. On physical examination, the dog was bright and alert. Complete blood counts, serum biochemistry and blood gas analysis results did not show any deviations within normal ranges. Radiographic and ultrasonographic examinations revealed unilateral hydronephrosis and hydroureter of the right kidney and ureter, and obstruction of the distal ureter was observed. On the basis of these results, nephroureterectomy was performed. During the operation, the adhesion of the distal ureter and surrounding tissue cells were observed without the evidence of the ureteral ligation. The distal ureteral obstruction was presumed to be adhesion caused by fibrous tissue formation between ureter and retained broad ligament, or incompletely removed blood clots following ovariohysterectomy. This case report describes the occurrence of hydroureteronephrosis caused by adhesion of the distal ureter following ovariohysterectomy in a bitch.