Case Description—A 4-month-old Missouri Fox Trotter colt was examined for a 5-week history of head tilt after treatment for suspected pulmonary Rhodococcus equi infection.
Clinical Findings—Computed tomography revealed osteolysis of the occipital, temporal, and caudal portion of the parietal bones of the left side of the cranium. A soft tissue mass compressing the occipital region of the cerebral cortex and cerebellum was associated with the osteolytic bone.
Treatment and Outcome—A rostrotentorial-suboccipital craniectomy approach was performed to remove fragmented occipital bone, debulk the intracranial mass, and obtain tissue samples for histologic examination and bacterial culture. All neurologic deficits improved substantially within 3 days after surgery. Bacterial culture of the resected soft tissue and bone fragments yielded R equi.
Clinical Relevance—Intracranial surgery in veterinary medicine has been limited to dogs and cats; however, in select cases, extrapolation of surgical techniques used in humans and small animals can assist with intracranial procedures in horses.
Case Description—A 13-year-old llama was examined because of lethargy, inappetence, and syncope.
Clinical Findings—Physical examination revealed muffled heart and lung sounds and peripheral edema. Clinicopathologic abnormalities included lymphopenia, hyperglycemia, prerenal azotemia, mild hyponatremia, mild hypoalbuminemia, and high γ-glutamyltransferase and creatine kinase activities. On ultrasonography, the liver appeared hyperechoic and ascites and pleural effusion were seen. Echocardiography revealed severe dilatation of the right atrium, right ventricle, and pulmonary artery; severe tricuspid regurgitation; and high right ventricular systolic pressure consistent with right-sided heart failure secondary to pulmonary hypertension.
Treatment and Outcome—Treatment with furosemide was attempted, but because of failing health, the llama was euthanized 4 weeks later. Macronodular cirrhosis of the liver, glomerulonephritis, and intimal fibrosis and medial hypertrophy of muscular pulmonary arteries were seen on histologic examination of postmortem specimens.
Clinical Relevance—Findings in this case were similar to those reported for human patients with portopulmonary hypertension secondary to hepatic cirrhosis. Pulmonary hypertension secondary to hepatic disease should be considered in the differential diagnosis of right-sided heart failure.
Case Description—An approximately 5-year-old sexually intact male alpaca was evaluated because of a right-sided maxillary mass that had recurred after previous surgical debulking.
Clinical Findings—Clinical, radiographic, and CT examination revealed an approximately 1.5-cm-diameter soft tissue mass associated with expansile osteolysis of the maxillary alveolar bone, beginning at the level of the right maxillary third premolar tooth extending caudally to the level of the rostral roots of the second molar tooth.
Treatment and Outcome—Right partial maxillectomy was performed, and histologic examination revealed an incompletely excised fibrosarcoma with osseous metaplasia. External beam radiation therapy to the tumor bed was initiated 1 month after surgery. Computerized planning was performed, and a total radiation dose of 48 Gy was prescribed in eleven 4.4-Gy fractions. Follow-up CT evaluations 6 and 58 weeks after radiation therapy was completed revealed no evidence of tumor recurrence. No clinical evidence of tumor recurrence was detected through 110 weeks after radiation therapy.
Clinical Relevance—The oral fibrosarcoma in the alpaca described here was successfully treated with surgical excision and adjuvant radiation therapy, resulting in excellent quality of life of the treated animal.
Objective—To evaluate samarium Sm 153 lexidronam (153Sm-EDTMP) as a treatment option for dogs with bony tumors of the skull.
Design—Retrospective case series.
Animals—Dogs with multilobular osteochondrosarcoma (MLO) or osteosarcoma (OSA) of the skull.
Procedures—Veterinary Medical Teaching Hospital records from the Universities of Missouri and Florida from 1986 to 2006 were searched for dogs with primary skull tumors treated with 153Sm-EDTMP.
Results—25 dogs were initially evaluated, with 5 dogs subsequently excluded because of inadequate follow-up or unrelated death. Seven OSAs and 13 MLOs were diagnosed. Tumors involved the occipital and frontal bones (n = 10), zygomatic arch and maxilla region (6), palate (3), and mandible (1). No clinically important adverse effects related to 153Sm-EDTMP treatment were documented. Of the 20 dogs evaluated 21 days after injection with 153Sm-EDTMP, 4 had subjective improvement, 13 had progressive disease, and 3 had insufficient follow-up. On the basis of radiographic findings, metastasis was suspected in 1 dog; 16 dogs had no metastasis evident, and medical records were insufficient for 3 dogs. Survival time, defined as the 153Sm-EDTMP injection date to the date of death, ranged from 3 to 1,314 days (median, 144 days).
Conclusions and Clinical Relevance—The subjective improvement in 4 patients and lack of clinical evidence of adverse effects suggested that 153Sm-EDTMP injection may be an option for the treatment of dogs with MLO or OSA of the skull when other treatments have failed or surgery is not possible.
Objective—To evaluate use of a radiolabeled peptide nucleic acid–peptide conjugate (RaPP) targeting B-cell leukemia-lymphoma 2 (BCL2) mRNA for scintigraphic detection of neoplastic lymphocytes in dogs with B-cell lymphoma and to assess associations among RaPP uptake, time to tumor progression (TTP), and BCL2 mRNA expression.
Animals—11 dogs with B-cell lymphoma and 1 clinically normal dog.
Procedures—Scintigraphic images were acquired 1 hour after IV injection of the RaPP. Regions of interest (ROIs) were drawn around lymph nodes, liver, and spleen; ROI intensity (relative to that of an equally sized region of muscle in the same image) was measured. Each ROI was also subjectively categorized as positive or negative for increased RaPP uptake. Expression of BCL2 mRNA was determined via quantitative reverse transcriptase PCR assay of a lymph node sample from dogs with lymphoma. Associations among imaging results, TTP, and BCL2 mRNA expression were evaluated.
Results—Increased RaPP uptake was detected in affected tissues of dogs with lymphoma. Dogs with superficial cervical lymph node ROIs categorized as negative (n = 8) for increased RaPP uptake had a significantly longer TTP than did dogs for which this ROI was considered positive (2). Measured intensity of mandibular and superficial cervical lymph node ROIs was negatively associated with TTP. Associations among BCL2 mRNA and ROI intensity or TTP were not significant.
Conclusions and Clinical Relevance—Increased RaPP uptake at mandibular or superficial cervical lymph node ROIs may be a negative prognostic indicator in dogs with lymphoma. A larger investigation is needed to determine clinical value of the RaPP for disease detection and prognostication.