A riding was presented for evaluation of an enlarging mass in the right cervical region and weight loss of 8 months' duration. The mass had been present for approximately 2 years, but had been increasing in size over the last few months. The owner estimated that the gelding had lost approximately 90 kg. The owner also reported that the gelding had exhibited several episodes of tachypnea associated with anhidrosis over the last 2 weeks and had noted behavioral abnormalities manifested as pacing in the paddock and difficulty when handled.On presentation, the gelding was thin, but was bright and alert. On physical examination, a firm, oblong mass approximately 12 X 9 cm was palpated dorsolateral to the trachea, immediately caudal to the angle of the mandible. The mass was loosely attached and nonpainful. Based on location, the mass was suspected to be a neoplastic thyroid gland. Normal rectal temperature (37.6"C), and respiratory rate (20 breathslminute) were present. However, an intermittent mild tachycardia (48-56 beatdminute) that lasted several minutes and occurred at various times throughout the day was noted. No other abnormalities were noted on clinical examination.Results of CBC and serum biochemistry were within reference range. A homogenous mass that was interspersed with several areas of centrally located hypoechoic foci was observed ultrasonographically, using a 7.5-MHz linear transducer (Ausonics Opus 1, Ausonics, Sydney, Australia). This structure was consistent with the right thyroid gland. Cytologic examination of a fine-needle aspirate of the mass revealed a population of oval to round cells with indistinct cytoplasmic borders, marked anisokaryosis, and prominent nucleoli. Some cells contained darkly pigmented cytoplasmic granules. These changes were consistent with thyroid adenocarcinoma,' but histopathology was recommended for definitive diagnosis (Fig 1).Baseline serum total thyroxine (TT,) concentration measured by a commercially available radioimmunoassay (RIA) kit was 12.4 nmol/L (normal reference range: 8. concentration measured using a commercially available equilibrium dialysis and RIA kit was >126.1 pmol/L (normal reference range: 8.8-30.4 pmol/L; Free T4 by Equilibrium Dialysis, Nichols Institute Diagnostics, San Juan Capistrano, CA). Both assay kits had previously been validated for use in horses.' These results were compatible with a functional thyroid tumor. Treatment options included surgical thyroidectomy or radioactive thyroid ablation using '''1. Adjunct treatment with antithyroid drugs such as methimazole or propylthiouracil also was considered. Surgical resection of the mass was elected due to financial considerations and the limited use of these drugs in horses.The horse was anesthetized and maintained with isoflurane in oxygen, and placed in lateral recumbency with the head and neck extended. A 12-cm skin incision was made caudal to the ramus of the mandible and ventral to the linguofacial vein. Blunt dissection was used to expose the tumorous thyroid gland. The mass was smoot...

Ultrasonographic features of canine abdominal malignant histiocytosis (MH) of 16 dogs are reported. The most common finding was the presence of hypoechoic nodules in the spleen, some of which caused distortion of the splenic margin. The liver was the second-most commonly affected organ. Hepatic ultrasonographic features were highly variable, including hypoechoic, hyperechoic, or mixed echogenic lesions. Other common ultrasonographic abnormalities included hypoechoic nodules in the kidneys and mesenteric and medial iliac lymphadenopathy. The results of this study suggest that the ultrasonographic appearance of canine abdominal MH is nonspecific, and definitive diagnosis requires cytologic or histologic examination.

The aim of this retrospective study was to determine the clinical usefulness of thoracic ultrasonography compared to thoracic radiography in evaluation of Rhodococcus equi pneumonia. Criteria for patient inclusion in this study were: (1) isolation of R. equi from transtracheal aspirate, (2) radiographic evaluation of the pulmonary parenchyma, and (3) sonographic evaluation of the pulmonary parenchyma. Seventeen foals met this criteria and their medical records were reviewed. Pyogranulomatous pneumonia was identified radiographically in 13 foals. Severe consolidative pneumonia with no detectable abscessation was identified radiographically in three others. Both consolidation and abscessation were identified radiographically in one. In this foal only consolidation was ultrasonographically identified. Ultrasonographically, pulmonary abscessation was identified in 12 foals and pulmonary consolidation with no detectable abscessation was identified in three others. Sonographic examination allowed detection of only pleural irregularities in one foal, which was subsequently found to have pyogranulomatous pneumonia radiographically. Results indicate that ultrasonography may be an accurate alternative imaging modality for detection of pulmonary pathology attributed to R. equi pneumonia in foals when thoracic radiography is not available.

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Clinical diagnosis of renal tumors in the horse has been difficult because the traditional diagnostic techniques are inadequate. Because of this shortcoming, early publications rarely reported antemortem diagnosis of primary renal tumors. Conventional radiographic techniques cannot effectively outline kidneys in the adult horse. With the advent of ultrasonography, a new dimension to the evaluation of the large‐animal kidney has been introduced. Percutaneous diagnostic ultrasonography provides a noninvasive method of examining both kidneys. This report describes a 15 year‐old Tennessee Walking Horse mare presented for evaluation of a mass in the sublumbar region, polyuria and polydipsia. Clinical examination and laboratory test results suggested intra‐abdominal neoplasia. Two‐dimensional ultrasonographic images of the mass were consistent with renal neoplasia. Histologic diagnosis of ultrasound‐guided renal biopsy was renal tubular cell carcinoma.