Background: The correlation between renal dimensions and renal function in cats with chronic kidney disease (CKD) is unclear. Hypothesis/Objectives: To investigate the relationship between renal dimensions and CKD severity in cats using ultrasound examination. Animals: Nineteen healthy cats and 30 cats with CKD. Methods: Renal ultrasound images obtained between 2012 and 2016 were reviewed. Severity of CKD was determined using the International Renal Interest Society CKD staging system. Renal length, cortical thickness, medullary thickness, and corticomedullary ratio were measured, and the relationship between these renal dimensions and serum creatinine concentrations as well as differences in dimensions between the control and disease groups was investigated. The sensitivity and specificity of the renal dimensions for differentiation of the CKD also were evaluated. Results: The disease group was subdivided into stage I to II (15 cats) and stage III to IV (15 cats) groups. Cortical thickness was significantly decreased in both disease groups and negatively correlated with disease severity. Compared with other renal dimensions, cortical thickness had a stronger linear correlation with the reciprocal of the serum creatinine concentration and superior diagnostic performance (Youden index: left kidney, 90.0% sensitivity and 94.7% specificity for a cutoff of 4.7 mm; right kidney, 83.3% sensitivity and 94.7% specificity for a cutoff of 4.5 mm). Conclusions and Clinical Importance: Decreased renal cortical thickness is observed in cats with loss of renal function. Measurement of cortical thickness using ultrasonography could be a useful method to evaluate the progression of CKD in cats.

Background: Osteosarcoma (OS) is the most common primary malignancy of the bone and is notoriously resistant to radiation therapy. High-dose cytotoxic chemotherapy and surgical resection have improved the survival rate and prognosis of patients with OS. Nonetheless, treatment challenges remain when the tumor cannot be removed by surgery. Boron neutron capture therapy (BNCT) provides high linear energy transfer (LET) radiation, and its internal targeted characteristics make BNCT a novel therapy for removing OS and reducing radiation damage to adjacent healthy tissues. Methods: In this study, a UMR-106-grafted OS rat model was developed, and boric acid (BA) was used as the boron drug for BNCT. The pharmacokinetics of BA, following intravenous injection, were evaluated to determine the optimal time window for neutron irradiation. OS-bearing rats were irradiated by an epithermal neutron beam at Tsing Hua Open-Pool Reactor (THOR). The therapeutic efficacy of and tissue response after BNCT were evaluated by radiographic and histopathological observations. Results: OS-bearing rats were irradiated by neutrons in the first hour following the intravenous injection of BA. The prescription-absorbed doses in the tumor regions were 5.8 and 11.0 Gy. BNCT reduced the body weight of the tumor-bearing rats, but they recovered after a few days. The BA-mediated BNCT effectively controlled the orthotopic OS tumor, reduced osteolysis, and induced bone healing. Autoradiography and histological analysis confirmed that the BA retention region is consistent with the calcification region in OS tissue. Conclusion: BA is specifically retained in OS, and the BA-mediated BNCT can significantly reduce the tumor burden and osteolysis in OS-bearing rats.

Summary: A 5-year-old female intact Mastiff dog was presented with a history of vaginal discharge for 1 day. Physical examination revealed a sanguineo- purulent vaginal discharge and systemic inflammatory response syndrome. Abdominal radiographs showed several dilated and gasfilled tubular loops. The differential diagnoses included emphysematous pyometra or small intestinal mechanical ileus. Surgical exploration of the abdomen demonstrated a severely dilated and gas-filled uterus, and emphysematous pyometra was confirmed. The patient’s clinical signs resolved after ovariohysterectomy. Histopathology revealed mild endometrial cystic hyperplasia with infiltration of inflammatory cells in the superficial endometrial epithelia. Enterococcus avium, an α-hemolytic gram-positive coccus, was isolated from the uterus. This paper highlights the radiographic features of emphysematous pyometra and a pathogen that has never been reported to be associated with canine pyometra previously.

Renal cortical anisotropy backscattering artifact (CABA) is a focal hyperechoic region where the tubules are parallel to the incident ultrasound beam, reflecting most of the beams to the transducer. To investigate the association between chronic kidney disease (CKD) and the absence of renal CABA in cats. Ultrasonographic renal images of 40 cats with CKD (stage II-IV) and 36 clinically healthy cats were blindly evaluated by two observers to determine the visibility of renal CABA. Inter- and intraobserver agreements were evaluated using McNemar’s test. The association between the absence of renal CABA and CKD was assessed using Fisher’s exact test. Excellent intraobserver and substantial interobserver agreements were demonstrated. A significant association (P < .0001) between absent renal CABA and CKD stage was revealed in all cats. Cats with CKD had an increased risk of the absence of renal CABA (Odds ratio, 56.0; 95% CI, 13.8–227.0) compared with the clinically healthy cats. The absence of renal CABA revealed 87.5% sensitivity and 88.9% specificity to detect CKD in all cats, and 91.7% sensitivity and 83.3% specificity in aged cats. Our study demonstrated a correlation between feline CKD and the absence of renal CABA, providing a feasible and alternative method for feline CKD evaluation.