Radiation therapy in the treatment of canine and feline thymomas: a retrospective study (1985-1999).

A retrospective study was performed of 17 dogs and seven cats with various stages of thymoma treated with radiation alone or as an adjunctive therapy. Analysis revealed an overall response rate of 75% (15/20 evaluable cases). Partial (i.e., >50% reduction in tumor size) and complete (i.e., no detectable tumor) responses were included. Complete responses were rare (4/20). Three of five animals with stable disease (i.e., <50% change in tumor size) had improvements in clinical signs, despite lack of measurable response. A median survival time of 248 days (range, 93 to 1,657+ days) was achieved in dogs, and a median survival time of 720 days (range, 485 to 1,825+ days) was achieved in cats. Radiation therapy appears to be useful in the management of invasive thymomas in dogs and cats.

A selected review of the physics of radiation therapy.

This article covers some of the basic physics needed to understand and plan radiation therapy. Special attention is given to those issues that are more common in veterinary radiation oncology. Far greater depth of discussion and explanation may be found in many standard texts and should be used for specific information and situations.

Neuroradiation oncology.

Neuroradiation oncology is a subdiscipline that is rapidly developing in veterinary practice. This article reviews the literature and emphasizes the positive results that are being achieved with better techniques and higher doses.

Radiation therapy in the treatment of oral neoplasia.

Oral neoplasia occasionally may be treated adequately with a single modality. Multimodality therapy, however, more often is indicated. This article reviews the recommendations of treatment of oral neoplasia focusing on the role of radiation therapy both singly and as a part of multimodality therapy.

Dry extracorporeal shock wave lithotripsy for treatment of ureterolithiasis and nephrolithiasis in a dog.

A second-generation lithotriptor was used to perform dry extracorporeal shock wave lithotripsy in a dog with ureterolithiasis, nephrolithiasis, and chronic renal failure. Previous studies on the use of lithotripsy in dogs have involved first-generation machines and have primarily concentrated on acute and chronic effects of lithotripsy in experimental models. Treatment in this dog resulted in resolution of ureteral obstruction, ureterolithiasis, and nephrolithiasis, and avoided complications associated with ureteral and renal surgery. The only complication was substantial hematuria of 12 hours' duration immediately after the procedure. Second-generation lithotripsy may offer an effective treatment for ureterolithiasis or nephrolithiasis in selected dogs.

The use of diagnostic computerized tomography and radiation therapy in canine and feline hyperadrenocorticism.

Therapy for canine pituitary-dependent Cushing's syndrome (PDC) has primarily been medical management with o,p'-DDD. This drug therapy does not directly affect the underlying pituitary pathology, and may have undesirable side effects. Pituitary-dependent Cushing's syndrome may be caused by pituitary microadenomas or macroadenomas. Advances in diagnostic imagery have allowed the antemortem diagnosis of pituitary macrotumors. Treatment of pituitary tumors may be attempted with radiotherapy, especially if a diagnosis of macrotumor can be made before the onset of profound neurologic signs.

Thread and sewing needles as gastrointestinal foreign bodies in the cat: a review of 64 cases.

Sixty-four cases of gastrointestinal linear foreign body in the cat were reviewed. Most of the cats were less than 4 years old. The most common clinical signs were persistent vomiting, partial to complete anorexia, and depression. Abdominal palpation by itself was rarely diagnostic. Diagnosis in approximately 75% of the cases was possible, however, by using a combination of oral examination and abdominal palpation. Survey radiography contributed to the diagnosis in 86% of the cases in which it was used, based on evidence of bowel plication, presence of tapered, enteric gas bubbles, gathering of the small intestine, peritonitis, intestinal needles, or bowel obstruction. Surgery (gastrotomy and multiple enterotomies) was necessary in 96.9% of the cases, and most of the cats so treated did well (83.9%). Approximately 50% of the cats with linear foreign body-induced bowel lacerations recovered.

Thymic branchial cysts in the dog and cat.

Branchial cysts of the thymus were diagnosed in 15 dogs and 2 cats. The main clinical sign was dyspnea. Pleural effusion varied in degree from minimal to severe. In all animals, an encapsulated mass in the cranial mediastinal region was found to consist of multiple epithelial cysts embedded in a stroma of fibrous connective tissue, adipose tissue, and vessels. Surgical resection of the cysts was performed in 7 dogs; 3 dogs survived and were clinically normal for 18 to 36 months.

Endomyocardial biopsy in the dog.

A technique for transvenous endomyocardial biopsy of the right ventricular septum was modified from an existing procedure described in man and was applied in the dog. More than 120 procedures were performed in 36 dogs. One dog died, but lesions noticed at necropsy were not sufficient to establish the specific cause of death. Other fatalities or major complications were not encountered.

Primary hyperparathyroidism in a dog.

A 6-year-old male Standard Poodle had hypercalcemia, hypophosphatemia, and a urinary concentrating defect. A parathyroid adenoma involving the left caudal parathyroid gland was surgically removed. Transient hypocalcemia followed, which resolved without treatment. A renal biopsy did not demonstrate renal parenchymal mineral deposition. Urinary concentrating ability returned after surgery.

Leiomyosarcoma of the urinary bladder in a cat.

An 81/2-year-old female domestic short-haired cat was admitted with signs of chronic cystitis. Radiography revealed marked and irregular thickening of the bladder wall. Biopsy revealed the thickening to be a malignant tumor of muscle origin and treatment with proteolytic enzymes was instituted. After one month, the cat was euthanatized because of uremia associated with progressive tumor growth. At necropsy the bladder was grossly thickened. The histopathologic diagnosis was leiomyosarcoma.