Mediastinal Serous Cavity Mesothelioma in Two Dogs.

The mediastinal serous cavity (MSC)-well documented but seldom recognized in the caudal mediastinum-is embryologically derived from the omental bursa. Mesothelioma arising from the MSC in two dogs is described. Both dogs presented with acute life-threatening hemorrhagic pleural effusion. Contrast computed tomography revealed a large solitary spherical-to-cylindrical tumor in the caudal mediastinum with variably thick, contrast-enhancing walls with lobular to frond-like proliferations that arose circumferentially and projected internally into a single, variably sized, fluid-attenuating lumen. The wall and lumen corresponded to the serous membrane and serous cavity of the MSC. Surgical exploration confirmed that both tumors arose from the mediastinum. Both had similar histologic findings, and special stains were necessary for definitive diagnosis. The tumor was nonresectable in one dog, and it was euthanized intraoperatively. The other survived 7 mo. An MSC mesothelioma should be considered a possible cause of hemothorax in dogs that may be detected on thoracic radiography and computed tomography. Differential diagnoses include esophageal foreign body or neoplasm, paraesophageal diaphragmatic hernia, MCS empyema, and pulmonary adenocarcinoma, with thoracic computed tomography helping to rule out foreign body and diaphragmatic hernia. For confirmed neoplasms, histochemistry and immunohistochemistry should be performed to differentiate between mesothelioma and pulmonary adenocarcinoma.

Hemothorax in Three Dogs with Intrathoracic Extracardiac Hemangiosarcoma.

Intrathoracic extracardiac hemangiosarcoma (HSA) is rare in dogs. This report describes three dogs with acute onset dyspnea due to hemorrhagic pleural effusion resulting from intrathoracic extracardiac masses, which were confirmed as HSA by histopathology. The dogs were stabilized with thoracocentesis and intravascular fluid resuscitation. Computed tomography identified intrathoracic masses, which were not originating from the heart or pulmonary parenchyma. Surgical exploration was performed in all cases. Case 1 was euthanized intraoperatively as the tumor could not be dissected from the aorta. In cases 2 and 3, hemostasis and resection of the tumors was successful. Case 2 was euthanized 1 mo after surgery and case 3 was alive at the time of writing, 5 mo postoperatively. Intrathoracic extracardiac HSA should be considered as a differential for nontraumatic hemothorax and surgical treatment can be palliative.

[Haemoabdomen and haemothorax in a cow with metastatic granulosa cell tumor]. / Hämoabdomen und Hämothorax bei einem Rind mit metastasierendem Granulosazelltumor.

This case report describes the clinical, ultrasonographic, pathological and histological findings in a two-year-old Swiss Braunvieh cow with granulosa cell tumor and metastases in the abdomen and thorax. The cow was ill and had tachycardia, coughing, increased breath sounds, positive reticular foreign body tests and a tense abdominal wall. Ultrasonography revealed a massive accumulation of hypoechoic fluid in the thorax and abdomen, and abdomino- and thoracocentesis yielded red fluid indicative of abdominal and thoracic haemorrhage. Because of a poor prognosis, the cow was euthanized and examined postmortem. Multiple nodular lesions were seen in the omentum, liver, spleen and lungs. The left ovary was grossly enlarged and nodular in appearance. Histological examination of the lesions revealed granulosa cell tumour of the left ovary and metastases in the omentum, liver, spleen and lungs.

Fatal hemothorax following management of an esophageal foreign body.

A 10.8-year-old, spayed female toy poodle presented with an esophageal foreign body. The foreign body was removed endoscopically, and a gastrostomy tube was placed to provide nutritional support during esophageal healing. The gastrostomy tube was later removed by endoscopic retrieval of the bulb through the esophagus. Immediately afterward, the dog developed hemothorax and eventually died. It was determined that many small arterial branches were avulsed from the aorta. The involved sections of aorta histopathogically evidenced medial necrosis, which was believed to be related to a prior disruption of blood flow through the vasa vasorum.

Hemiurothorax following diaphragmatic hernia and kidney prolapse in a cat.

A 3-year-old cat was presented with increasing dyspnoea over the past four days. Unilateral pleural effusion was diagnosed and a modified transudate was drained several times. Surgical exploration revealed intra-thoracic prolapse of the left kidney and partial herniation of the spleen through a dorsal, circumferential diaphragmatic tear. Biochemical analysis of the pleural fluid confirmed urothorax. Due to excessive fibrin deposit on the well-vascularised kidney it was impossible to re-establish left urinary pathways. Left-sided nephrectomy and diaphragmatic herniorrhaphy were performed. Postoperative recovery was uneventful and complete. This is the first report of an urothorax in veterinary medical literature.

Hemothorax in 2 horses.

This report documents the successful conservative medical management of hemothorax in 2 horses. Hemothorax occurred after a lung biopsy procedure (horse 1) and strenuous exercise on a treadmill (horse 2). The horses had tachypnea, tachycardia, nostril flaring, hemoptysis, and pawing. Hemothorax was suspected based upon absence of auscultable ventral lung sounds; development of cool extremities and pale, tacky mucous membranes; the ultrasonographic appearance of moderate to severe amounts of pleural fluid; and a concurrent decrease in hematocrit and total plasma protein. Both horses were treated successfully by intranasal administration of oxygen, intravenous administration of balanced polyionic solutions, and treatment with antibiotics, nonsteroidal anti-inflammatory drugs, and analgesics. In neither case was pleural blood removed. The hemothorax resolved in both horses without lasting abnormalities. Hemothorax does not require drainage for successful resolution.

A survey of koala road kills in New South Wales.

Between 1984 and 1990, 75 koalas (Phascolarctos cinereus) from the central northern coast of New South Wales (Australia) were presented for necropsy due to motor vehicle accidents. The koalas consisted of 44 males and 31 females. Fifty one of these were between 2 and 7 yr (39 males and 12 females). The greater proportion of koalas, especially males, were struck by vehicles between June and December. The main injuries detected were head injuries (44), hemoperitoneum (16), limb injuries (16), hemothorax (15) and spinal injuries (7). Nine koalas were not dead at the time of the accident but died later following complications from the trauma. Twelve koalas had evidence of underlying disease at the time of accident. Ten of these had either conjunctivitis, cystitis, prostatitis, periovarian cysts, endometritis or a combination of the diseases. All 10 koalas still had good body condition. It is suggested that healthy young to middle-aged males are particularly prone to vehicular accidents during the mating period. This has implications for the management of local koala populations.

Pleural effusions and diseases of the pleura.

There are four factors that govern fluid movement to or from the pleural space: hydrostatic pressure, colloid osmotic pressure, filtration coefficient, and lymphatic function. When any of these factors are altered, fluid accumulates within the pleural space. Congestive heart failure, pancreatitis, neoplasia, hypoalbuminemia, and pulmonary thromboembolism can evoke pleural effusions by altering normal fluid transport mechanisms. This approach to pleural effusion helps to explain fluid accumulation. Chylothorax, hemothorax, and empyema are also covered in the article.

Hemothorax associated with telangiectatic osteosarcoma in a dog.

Hemothorax in a dog was attributed to bleeding from an intrathoracic mass attached to the sixth through the tenth ribs. The mass contained numerous cavernous, blood-filled spaces as well as bands of osteoid and occasional foci of osseous tissue. The diagnosis was telangiectatic osteosarcoma. Telangiectatic osteosarcoma is an uncommon variant of osteosarcoma. Cavernous, blood-filled spaces and paucity of bone are important histologic features. Metastasis was described in one of the seven telangiectatic osteosarcomas reported in dogs, and none was found in this case.

Thoracic trauma.

The physiologic equilibrium of chest injury patients is frequently precarious, and mild stress during examination and treatment may precipitate acute decompensation and death. This is particularly true with the respiratory system, where the normally large respiratory reserve capacity may be rapidly lost. Accurate assessment of the nature of the thoracic injury and the severity of that injury must be determined in order to formulate a therapeutic plan. Many thoracic injuries, such as pneumothorax, pulmonary contusions, or rib fractures, will be self-limiting. Other conditions must be recognized for their potentially lethal nature and dealt with aggressively, and these include cardiac tamponade, tension pneumothorax, and esophageal perforation. By performing a systematic evaluation of the patient and confirming or denying the presence of all possible types of thoracic injury, the veterinarian may avoid overtreatment of self-limiting lesions and recognize and aggressively treat those with potentially fatal outcomes.

[Dyspnoea due to intrathoracic haemorrhage and haemangiosarcoma in a horse (author's transl)]. / Benauwdheid intrathoracale verbloeding met haemangiosarcomen bij een paard

Post-morten examination of a fourteen-year-old mare of the Gelderland breed, which had been treated for severe dyspnoea and had subsequenlty died, revealed the presence of haemothorax, atelectasis of the lung and a metastasized haemangiosarcoma of the left ovary. The haemothorax could have resulted from rupture of one of the metastases.