Usefulness of serum amyloid A for the diagnosis of pyelonephritis in cats: A prospective evaluation.

BACKGROUND: The diagnosis of pyelonephritis in cats is challenging and development of a noninvasive and accurate biomarker is needed. HYPOTHESES: Serum amyloid A (SAA) is increased in cats with pyelonephritis, but not in cats with other urinary tract diseases. ANIMALS: A cohort of 125 cats (149 observations). METHODS: This was a prospective study. Group 1 included cats with a diagnosis of pyelonephritis either confirmed by bacterial culture of pelvic urine (Group 1a) or presumed (1b). Group 2 included cats for which pyelonephritis was ruled out (with certainty: Group 2a or judged unlikely: Group 2b). SAA concentration was compared between groups, and accuracy of SAA for the diagnosis of pyelonephritis was calculated using a Receiver Operating Characteristic (ROC) curve analysis. RESULTS: Median SAA concentration was significantly higher in Group 1a (86.8 mg/L [73.3; 161.5]; n = 8) than in Group 2a (4 mg/L [1.8; 5.6], n = 19; P < .001) and in Group 2b (5.4 mg/L [3.1; 9.7], n = 113; P < .001). It was also significantly higher in Group 1b (98.8 mg/L [83.1; 147.3]; n = 9) than in Group 2b (P < .001) and Group 2a (P < .001). Optimal diagnostic cut-off for SAA concentration was 51.3 mg/L. yielding a sensitivity of 88% (95% confidence interval: [64%; 99%]) and a specificity of 94% (95% confidence interval: [88%; 97%]). CONCLUSIONS AND CLINICAL IMPORTANCE: Measurement of SAA could be used to rule out pyelonephritis in the case of low suspicion of the disease. Increased SAA concentration is suggestive of pyelonephritis despite a lack of specificity.

Alendronate treatment in cats with persistent ionized hypercalcemia: A retrospective cohort study of 20 cases.

BACKGROUND: Limited information is available concerning treatment of ionized hypercalcemia in cats. HYPOTHESIS/OBJECTIVES: Describe clinical findings in a cohort of cats with persistent ionized hypercalcemia and evaluate long-term tolerance and efficacy of alendronate in these patients. ANIMALS: Twenty cats with persistent ionized hypercalcemia of undetermined origin, presented for routine or referral consultation at the teaching hospital of Maisons-Alfort (France). METHODS: Medical records were retrospectively reviewed. Cats were divided into Group 1 (cats that received alendronate as well as other treatments, n = 11) and Group 2 (cats that did not receive alendronate, n = 9). Survival analysis (Kaplan-Meier method, log-rank test, and Cox proportional hazard models) was conducted to compare time to selected outcomes. RESULTS: Azotemia was present in 15 cats (75%). Alendronate treatment was administered and well tolerated during the entire follow-up period (median, 9.5 months; interquartile range [IQR], 6.3; 27) in all cats from Group 1, except in 1 cat that developed severe hypophosphatemia, prompting treatment discontinuation. Univariate analysis determined that alendronate treatment was significantly associated with shorter time to reach a 15% decrease in ionized calcium concentration (iCa) from baseline during follow-up (119 days vs median not reached, P = .02). This association was no longer significant after adjustment for age and initial iCa. CONCLUSIONS AND CLINICAL IMPORTANCE: Alendronate overall was well tolerated with chronic use in this cohort, and can be considered a treatment option for persistent ionized hypercalcemia in cats.

Renal adenocarcinoma associated with hypertrophic osteopathy in a cat.

CASE SUMMARY: A 10-year-old neutered male domestic shorthair cat was diagnosed with renal adenocarcinoma associated with hypertrophic osteopathy. The cat was referred for chronic ambulation difficulties. The physical examination showed a painful thickening of all four limbs, a right cranial abdominal mass and a conjunctival hyperaemia. Radiographic findings were consistent with extensive periosteal new bone formation involving not only the diaphyses of the fore- and hindlimbs, but also of the pelvis, tarsus and carpus. Abdominal ultrasonography and CT revealed a mass within the right kidney and a primary neoplasm was suspected. A ureteronephrectomy of the right kidney was performed and histopathology confirmed the diagnosis of renal adenocarcinoma. Although clinical improvement of the lameness occurred after surgery, no radiographic changes of hypertrophic osteopathy lesions were observed at the 9-month follow-up. RELEVANCE AND NOVEL INFORMATION: Feline cases of hypertrophic osteopathy are rarely reported in the literature and only a few of them were associated with abdominal neoplastic diseases. To our knowledge, this is the first case of renal adenocarcinoma associated with hypertrophic osteopathy in a cat.