Long-term outcome of domestic ferrets treated surgically for hyperadrenocorticism: 130 cases (1995-2004).

OBJECTIVE: To determine the long-term survival rate and factors that affect survival time of domestic ferrets treated surgically for hyperadrenocorticism. STUDY DESIGN: Retrospective case series. ANIMALS: 130 ferrets with hyperadrenocorticism that were treated surgically. PROCEDURES: Medical records of ferrets surgically treated for hyperadrenocorticism were reviewed. Data recorded included signalment, duration of clinical signs prior to hospital admission, CBC values, serum biochemical analysis results, anesthetic time, surgical time, concurrent diseases, adrenal gland affected (right, left, or both [bilateral]), histopathologic diagnosis, surgical procedure, caudal vena caval involvement (yes or no), postoperative melena (yes or no), days in hospital after surgery, and whether clinical signs of hyperadrenocorticism developed after surgery. RESULTS: 130 ferrets were entered in the study (11 of 130 ferrets were admitted and underwent surgery twice). The 1- and 2-year survival rates were 98% and 88%, respectively. A 50% survival rate was never reached. Combined partial adrenal gland resection with cryosurgery had a significantly negative effect on survival time. No other risk factors were identified. Survival time was not significantly affected by either histopathologic diagnosis or specific affected adrenal gland (right, left, or bilateral). CONCLUSIONS AND CLINICAL RELEVANCE: Ferrets with adrenal gland masses that were treated surgically had a good prognosis. Survival time of ferrets with hyperadrenocorticism undergoing surgery was not affected by the histologic characteristic of the tumor, the adrenal glands affected (right, left, or bilateral), or complete versus partial adrenal gland resection. Debulking was a sufficient surgical technique to allow a favorable long-term outcome when complete excision was not possible.

Comparison of radiographic and anatomic femoral varus angle measurements in normal dogs.

OBJECTIVE: To determine if the clinically practiced method of radiographic femoral varus angle (R-FVA) measurement is repeatable, reproducible, and accurate. STUDY DESIGN: Radiographic and anatomic study. ANIMALS/SAMPLE POPULATION: Normal Walker hound cadavers (n=5) and femora (n=10). METHODS: Cadavers were held in dorsally-recumbent and torso-elevated positions as 3 craniocaudal radiographs were made of each femur, by each of 2 different technicians. Femora were then harvested for direct measurement of anatomic femoral varus angle (A-FVA). R-FVA was measured on each radiograph by each of 3 examiners on 3 separate occasions. Intra-observer (repeatability) and inter-observer (reproducibility) variance in R-FVA measurement and the strength of relationship between R-FVA and A-FVA (accuracy) were determined. RESULTS: Mean (+/-SD) A-FVA was 5.2+/-2.1 degrees (range, 2.4-8.2 degrees). Mean (+/-SD) R-FVA was 5.8+/-1.0 degrees (range, 2.7-9.6 degrees). Intra-observer variance (range: 11-16%) and inter-observer variance (16%) were acceptable. The strength of relationship between measured R-FVA and A-FVA (maximum adjusted R(2)<0) was unacceptably low regardless of observer, patient position, or radiographic technician. CONCLUSION: R-FVA measurement was repeatable and reproducible, but not statistically accurate in predicting A-FVA in these 5 normal Walker hounds. The detected inaccuracy may be real or the result of a selection bias for normal dogs obscuring the true relationship. CLINICAL RELEVANCE: R-FVA may not be an accurate method of femoral varus measurement in dogs with A-FVA<10 degrees. Using Slocum's criteria for distal femoral osteotomy (R-FVA>10 degrees), the procedure would not have been erroneously performed in any of the normal dogs of this study.

Long-term outcome of distal femoral osteotomy for treatment of combined distal femoral varus and medial patellar luxation: 12 cases (1999-2004).

OBJECTIVE: To determine long-term outcome of distal femoral osteotomy as a component of treatment for distal femoral varus and medial patellar luxation in large-breed dogs. DESIGN: Retrospective case series. ANIMALS: 12 dogs (16 stifle joints). PROCEDURES: Medical records and radiographs were reviewed to identify large-breed dogs with medial patellar luxation (grade > or = 2) and femoral varus angle > or = 12 degrees treated with distal femoral osteotomy, with a minimum follow-up (by a veterinarian) of 18 months. Signalment, weight, medial patellar luxation and lameness grade, pre- and postoperative femoral varus angle, surgical technique, time to radiographic bone union, and complications were recorded. Follow-up with owners via questionnaire was performed > 18 months after surgery. RESULTS: 16 corrective distal femoral osteotomies were performed with ancillary medial patellar luxation procedures in 12 dogs; 4 dogs had staged bilateral procedures. Mean +/- SD preoperative and postoperative femoral varus angles were 16.3 +/- 4.3 degrees and 3.9 +/- 2.5 degrees , respectively. Mean +/- SD time to radiographic union of the distal femoral osteotomy was 52.6 +/- 13 days. One dog had Kirschner wire migration from the tibial tuberosity. Patellar luxation was not detected after surgery in any dog. Mean +/- SD follow-up by a veterinarian was 1,335 +/- 410 days and by use of an owner questionnaire was 1,497 +/- 464 days. All 10 variables of owner-observed patient comfort and function were significantly improved. CONCLUSIONS AND CLINICAL RELEVANCE: Distal femoral osteotomy in combination with traditional treatment provided predictable osteotomy healing, patellar stabilization, and long-term improvement in patient comfort and function when used to treat combined distal femoral varus and medial patellar luxation in large-breed dogs.