Identification of occult micrometastases and isolated tumour cells within regional lymph nodes of previously diagnosed non-metastatic (stage 0) canine carcinomas.

Metastatic dissemination of carcinomas to lymph nodes impacts prognosis and treatment recommendations in human and veterinary medicine. Routine histopathologic evaluation of regional lymph nodes involves haematoxylin and eosin (H&E) staining to identify intra-nodal neoplastic cells; however, identification of small volume metastases (micrometastases and individual tumour cells) may be missed without the aid of immunohistochemistry or additional step-sections. The aim of this study was to identify occult carcinoma metastases in previously diagnosed non-metastatic lymph nodes using step-sections and pancytokeratin (panCK) immunohistochemistry. Samples from 20 regional lymph nodes diagnosed as non-metastatic were serially sectioned and evaluated with panCK. Of these, 25% (n = 5) contained micrometastases (n = 1) or isolated tumour cells (n = 4). This study demonstrates the increased efficacy of serial step-sections combined with panCK immunohistochemistry to identify small volume metastases in regional lymph nodes. The prognostic significance of micrometastases and isolated tumour cells in regional lymph nodes warrants further investigation in veterinary medicine.

Ultrasound and computed tomography of the iliosacral lymphatic centre in dogs with anal sac gland carcinoma.

In this prospective study, we hypothesized that computed tomography (CT) would identify more normal and abnormal iliosacral lymph nodes (LNs) than abdominal ultrasound in dogs with anal sac gland carcinoma (ASGC). Twelve client-owned dogs with ASGC but without distant metastasis were enrolled. Abdominal ultrasound and contrast-enhanced CT scans of the abdomen were obtained. Iliosacral LNs were counted and assessed for location, laterality and size. Significantly (P < 0.00001) more iliosacral LNs were identified with CT (61) than ultrasound (30), including significantly (P = 0.00012) more medial iliac LNs with CT (33) than ultrasound (19). There was no difference in number of internal iliac LNs identified with CT versus ultrasound. Significantly (P = 0.000061) more sacral LNs were identified with CT (15) than ultrasound (0). Ultrasound identified slightly more (7) abnormal iliosacral LNs than CT (5). Contrast CT was able to identify more normal but not more abnormal LNs than ultrasound.

Upper airway obstruction in Norwich Terriers: 16 cases.

BACKGROUND: Norwich Terriers have grown increasingly popular as show animals and pets, and awareness of respiratory problems within the breed is growing. OBJECTIVE: To describe components of obstructive upper airway syndrome in a nonbrachycephalic terrier breed. ANIMALS: Sixteen Norwich Terriers; 12 with and 4 without clinical signs of respiratory disease. METHODS: Prospective case series. Physical and laryngoscopic examinations were performed by 1 investigator in all dogs. Medical and surgical interventions were summarized and results of follow-up examination or owner reports were recorded. RESULTS: The study population was comprised of 9 females (6 intact) and 7 males (5 intact). Median age was 3.0 years (range, 0.5-11 years). Of 12 dogs presented for a respiratory complaint, physical examination was normal in 4 dogs. Laryngoscopic examination was abnormal in 11/12 dogs with redundant supra-arytenoid folds, laryngeal collapse, everted laryngeal saccules, and a narrowed laryngeal opening in most. Of 4 dogs lacking clinical signs, all had normal physical examination; however, 3/4 dogs had similar appearance of the larynx to dogs with clinical signs. Response to surgical intervention was minimal to moderate in all dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Norwich Terriers suffer from an upper airway obstructive syndrome that differs from that encountered in brachycephalic breeds. Affected dogs are difficult to identify without laryngoscopic examination because of the lack of clinical signs and abnormalities in physical examination findings, despite severe airway obstruction. Care is warranted when anesthetizing Norwich Terriers because of the small size of the laryngeal opening.

Outcome in dogs with surgically resected oral fibrosarcoma (1997-2008).

Oral fibrosarcoma (FSA) is a common oral tumour in dogs, and historically reported survival times after surgical excision range from 7.0 to 12.2 months with local recurrence rates of 32-57%. The purpose of this retrospective study was to report outcome in a cohort of dogs with oral FSA treated with surgical excision with or without adjuvant radiation therapy. Twenty-nine dogs with a histological diagnosis of FSA arising from the oral cavity that underwent surgical resection of their oral FSA were included in this study. Twenty-one dogs were treated with surgical excision alone and eight dogs with both surgery and radiation therapy. The median progression-free interval was >653 days. The median survival time was 743 days. The 1- and 2-year survival rates were 87.7 and 57.8%, respectively. Seven (24.1%) dogs developed local recurrence. Seven dogs (24.1%) developed metastasis.

Diagnosis and surgical management of ureteral calculi in dogs: 16 cases (1990-2003).

AIMS: To examine the clinical signs, laboratory and radiographic findings, surgical technique, ureterolith composition, and post-operative outcomes in dogs managed surgically for ureterolithiasis to determine whether surgical removal of ureteroliths in dogs resulted in a positive clinical outcome. METHODS: The medical record database of a university veterinary hospital in Pennsylvania, USA, was searched for dogs that underwent surgery to remove obstructive ureteral calculi between 1990 and 2003. Records were reviewed for signalment, clinical history and examination findings, radiographic and laboratory test results, surgical technique, and ureterolith analysis. Follow-up information was obtained from telephone interviews with owners or referring veterinarians, or by reviewing the medical record of subsequent hospital visits. RESULTS: Sixteen dogs were included in this study; ten were neutered females, two intact females and four castrated males. Abdominal radiography revealed ureteral calculi in 14/16 dogs, renal calculi in 8/16, cystic calculi in 8/16, urethral calculi in 1/16, renomegaly in 6/16 and renal mineralisation in 5/16. Ureterolith type included struvite in six dogs, calcium oxalate in five, calcium phosphate in one, and a mix of struvite, calcium phosphate and calcium oxalate in another. Compared to dogs with non-struvite ureteroliths, those with struvite ureteroliths had a higher pre-operative white blood cell (WBC) count (25.6, SD 7 vs 17.6, SD 6 x 103 cells/mul; p=0.046), and were more likely to have a purulent discharge from the ureteral incision noted at the time of surgery (p=0.015). Following discharge, 14/16 dogs were re-evaluated. Median survival time was 904 days (range 2-1,876). Two dogs required additional surgery on the urinary tract. Four dogs died or were euthanised because of azotaemia and clinical signs related to the urinary system or non-specific signs of illness (vomiting, lethargy) at 8, 90, 333 and 904 days post-operatively. CONCLUSIONS: Surgical management of ureteroliths was successful and resulted in good long-term survival in the majority of dogs examined in this small study population. Similar proportions of calcium oxalate and struvite ureteroliths were identified. CLINICAL RELEVANCE: The use of the ureteral surgery may increase as the frequency of diagnosis of ureteroliths in dogs increases.

Use of sevoflurane for anesthetic management of horses during thoracotomy.

OBJECTIVE: To evaluate sevoflurane as an inhalation anesthetic for thoracotomy in horses. ANIMALS: 18 horses between 2 and 15 years old. PROCEDURE: 4 horses were used to develop surgical techniques and were euthanatized at the end of the procedure. The remaining 14 horses were selected, because they had an episode of bleeding from their lungs during strenuous exercise. General anesthesia was induced with xylazine (1.0 mg/kg of body weight, IV) followed by ketamine (2.0 mg/kg, IV). Anesthesia was maintained with sevoflurane in oxygen delivered via a circle anesthetic breathing circuit. Ventilation was controlled to maintain PaCO2 at approximately 45 mm Hg. Neuromuscular blocking drugs (succinylcholine or atracurium) were administered to eliminate spontaneous breathing efforts and to facilitate surgery. Cardiovascular performance was monitored and supported as indicated. RESULTS: 2 of the 14 horses not euthanatized died as a result of ventricular fibrillation. Mean (+/- SD) duration of anesthesia was 304.9 +/- 64.1 minutes for horses that survived and 216.7 +/- 85.5 minutes for horses that were euthanatized or died. Our subjective opinion was that sevoflurane afforded good control of anesthetic depth during induction, maintenance, and recovery. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of sevoflurane together with neuromuscular blocking drugs provides stable and easily controllable anesthetic management of horses for elective thoracotomy and cardiac manipulation.