RADIOGRAPHIC FEATURES OF AORTIC BULB/VALVE MINERALIZATION IN 20 DOGS

The radiographic features of aortic bulb/valve mineralization in 20 dogs were reviewed. Extent, shape, number, and location of mineralization were recorded. Five of the dogs had additional alternate imaging examinations, including bone scintigraphy, echocardiography, and thoracic computed tomography. A necropsy was done on one dog, and the area of mineralization was evaluated using routine histology. The median age was 10 (mean 9.7; SD +/- 2.7) years. There were five males, seven neutered males, one female, and seven neutered females. The breeds were: Irish setter (6); rottweiler (7); chow-chow (1); miniature dachshund (1); borzoi (1); English setter (1); English springer spaniel (1); great Dane (1); and greyhound (1). Dogs with both right and left lateral radiographs (n = 17) had mineralization visible on both views, more conspicuously on the right lateral radiograph (n = 12). Aortic bulb mineralization was identified on the ventrodorsal radiograph of only one dog. On lateral radiographs, the aortic bulb mineralization was localized within the 4th intercostal space and in the craniodorsal quadrant of the cardiac silhouette. In nine of the dogs, there were complex or multiple mineralizations and in 11 dogs, there was a single curvilinear mineral opacity oriented in a caudoventral to craniodorsal direction. In all radiographs, the mineralization was in the expected position of the aortic bulb, and echocardiography (n = 4), spiral computed tomography (n = 2), and necropsy (n = 1) confirmed that the mineralization was within the aortic bulb. Clinical pathologic data of the dogs suggested no reason for metastatic mineralization. Exact etiopathogenesis of the lesions were not determined in this study. Based on the histologic findings in one dog, the mineralization seen in the aortic root is similar to a form of dystrophic mineralization called Monckeberg's calcific arteriosclerosis in humans. No clinical signs attributable to the mineralization were observed.     

Aberrant migration and surgical removal of a heartworm (Dirofilaria immitis) from the femoral artery of a cat

A cat was evaluated for an acute‐onset of right pelvic limb paresis. Thoracic radiographs revealed normal cardiac size and tortuous pulmonary arteries. Abdominal ultrasound identified a heartworm (HW) extending from the caudal abdominal aorta into the right external iliac artery and right femoral artery. The cat was HW‐antigen positive. Echocardiography revealed a HW within the right branch of the main pulmonary artery and evidence of pulmonary hypertension. An agitated‐saline contrast echocardiogram revealed a small right to left intracardiac shunt at the level of the atria. Surgical removal of the HW was performed with no substantial postoperative complications. There was return of blood flow and improved motor function to the limb. The cat remains mildly paretic on the affected limb with no other clinical signs.     

Vascular ring anomaly with coarctation of the aorta in a cat

A 13-week-old, entire male domestic shorthaired cat was presented with a nine-week history of regurgitation following the ingestion of food. A diagnosis of a vascular ring anomaly with coarctation of the aorta was based on clinical signs, angiography and echocardiography. Surgical exploration via a right lateral thoracotomy confirmed the existence of a persistent right aortic arch with right ligamentum arteriosum, aortic coarctation and an aberrant left subclavian artery. Following the surgical transection of the aberrant left subclavian artery, the cat made an uneventful recovery, showing normal swallowing function with no evidence of regurgitation. Twelve months after surgery, the cat had no special dietary requirements and remained clinically normal.     

Cholecalciferol rodenticide intoxication in a cat.

A 4-month-old 2.5-kg sexually intact female domestic shorthair cat was referred to the teaching hospital because of suspected cholecalciferol intoxication after ingestion of a cholecalciferol-containing rodenticide. At referral, the cat was hypercalcemic, hyperkalemic, and acidotic. Despite management of hypercalcemia and preservation of renal function with physiologic saline solution, furosemide, dopamine, and calcitonin, the cat died, apparently as a result of extensive pulmonary mineralization.     

IMAGING DIAGNOSIS—MULTIMODALITY FINDINGS IN AN ADULT DOG WITH PRIMARY SARCOMA OF THE PULMONARY ARTERY AND MYOCARDIAL METASTASES

Intravascular pulmonary artery sarcomas in combination with myocardial metastasis are rare in dogs. We describe the radiographic, echocardiographic, and electrocardiographic‐gated (ECG‐gated) computed tomographic angiography (CTA) findings in a dog with pulmonary artery sarcoma. All imaging studies demonstrated severe main pulmonary artery enlargement. Echocardiography and ECG‐gated CTA revealed a mass occluding the lumen of the right pulmonary artery. In addition, CTA revealed focal left ventricular myocardial contrast enhancement and parenchymal lung changes. Postmortem examination confirmed the presence of a large thrombus associated with arteriosclerosis and an intravascular sarcoma in the right pulmonary artery with metastases to the myocardium, lungs and brain.     

Aortic body chemodectoma causing pulmonary oedema in a cat

A seven-year-old male domestic shorthaired cat was presented with persistent dyspnoea. Thoracic radiography and echocardiography revealed pulmonary oedema and a mass at the base of the heart. At necropsy the mass was found to be an aortic body chemodectoma that had metastasised to the sternal lymph node. This is a rare tumour in the cat, the third reported case where there was evidence of metastasis, and only the second reported case where there was evidence of lymphocytic infiltration of the primary tumour. Pulmonary oedema is an unusual presentation of this tumour in the cat.     

Longitudinal left ventricular myocardial dysfunction assessed by 2D colour tissue Doppler imaging in a dog with systemic hypertension and severe arteriosclerosis

A 12-year-old sexually intact male Vendee Griffon Basset was presented for acute pulmonary oedema. Severe systemic systolic arterial hypertension (SAH) was diagnosed (290 mmHg). Despite blood and abdominal ultrasound tests, the underlying cause of the systemic hypertension could not be determined, and primary SAH was therefore suspected. Conventional echocardiography showed eccentric left ventricular hypertrophy with normal fractional shortening. Despite this apparent normal systolic function, 2D colour tissue Doppler imaging (TDI) identified a marked longitudinal systolic left ventricular myocardial alteration, whereas radial function was still preserved. Three months later, the dog underwent euthanasia because of an acute episode of distal aortic thromboembolism. Necropsy revealed severe aortic and iliac arteriosclerosis. SAH related to arteriosclerosis is a common finding in humans, but has not been previously described in dogs. Moreover, its consequence on longitudinal myocardial function using TDI has never been documented before in this species.     

Plexogenic pulmonary arteriopathy in a cat with non‐restrictive ventricular septal defect and chronic pulmonary hypertension

A 10‐week‐old, male, domestic long‐hair cat was medically managed for congenital heart disease over a period of 8 years. Regular clinical examinations, including sequential echocardiography, documented a non‐restrictive paramembranous ventricular septal defect, secundum‐type atrial septal defect and aortic dextroposition. Pulmonary arterial hypertension was diagnosed by the presence of high‐velocity tricuspid regurgitation, bidirectional low velocity flow across the ventricular septal defect, pulmonary arterial dilation and severe right ventricular hypertrophy without evidence of pulmonary outflow tract obstruction. The cat remained clinically stable until it died suddenly at 8 years of age. Histopathology of the lungs found evidence of plexogenic pulmonary arteriopathy. Despite severe pulmonary vascular lesions, other post‐mortem evidence of right heart failure was lacking and death was attributed to a fatal cardiac arrhythmia. In this case report of a cat with chronic pulmonary hypertension over 8 years, plexogenic lesions were found on histopathology. The microscopic findings resemble those previously reported in dogs.     

Peripheral pulmonary artery stenosis in three cats

Case 1 involved a 4-month-old intact male Somali cat in which peripheral pulmonary artery stenosis (PPS) was recognized after a cardiac murmur remained following patent ductus arteriosus ligation. Case 2, which involved a 1-year-old neutered male Norwegian Forest cat, and Case 3, which involved a 6-month-old intact female American Curl cat, were referred, because of cardiac murmurs. Grades III to IV/VI systolic heart murmurs were auscultated at the left heart base in all 3 cats. All cases showed bilateral pulmonary artery stenosis, although there were no associated clinical signs. In Cases 1 and 2, the pressure gradient through the stenosis decreased after treatment with atenolol.     

AORTIC AND CARDIAC MINERALIZATION IN THE DOG

Aortic and cardiac mineralization was found in 21 of 3443 (0.61%) canine thoracic radiographs. In none of 786 feline thoracic radiographs reviewed were such lesions present. Mineralizations were superimposed on the ascending aorta (19 dogs) or on the caudal cardiac silhouette (2 dogs). In 2 of 4 dogs mineralization was identified echocardiographically dorsal to the aortic valve in close proximity to coronary arteries. Computed tomography confirmed mineralization of the aortic arch and root in 2 of 2 dogs. Necropsy and histopathologic examination in 1 dog revealed multiple nodular aortic tunica media calcifications with adjacent areas of degeneration. Lesions were significantly overrepresented in older dogs and in Rottweilers, and regarded as dystrophic calcification, caused either by age-related degenerative changes or chronic disease-related processes. There was no evidence of clinical significance attributed to the mineralization in any dog. Aortic and cardiac mineralization should be recognized as an incidental, non-significant finding in dogs of advanced age and differentiated from pleural and pulmonary structures.     

Palliative balloon angioplasty in a cat with right pulmonary arterial branch stenoses and concurrent absence of the left pulmonary artery

Unilateral absence of the left or right pulmonary artery with concurrent contralateral pulmonary arterial branch stenoses is an exceptionally rare disorder. We describe this anomaly in a cat with severe exercise intolerance and respiratory distress. Transthoracic echocardiography and angiography demonstrated the absence of the left pulmonary artery with concurrent right pulmonary branch stenosis. Palliative balloon angioplasty of the right pulmonary artery substantially reduced right ventricular systolic pressure load and alleviated the patient's clinical signs.     

Unusual vascular ring anomaly associated with a persistent right aortic arch in two dogs

An unusual vascular ring anomaly consisting of a persistent right aortic arch and a left ligamentum arteriosum extending from the main pulmonary artery to an aberrant left subclavian artery and left aortic arch remnant complex was identified in a German shepherd dog and a great Dane. The left subclavian artery and left aortic arch remnant complex originated at the junction between the right distal aortic arch and the descending aorta and coursed dorsal to the oesophagus in a cranial direction. The attachment of the ligamentum arteriosum to the aberrant left subclavian artery was approximately 5 cm cranial to the point of origin of the aberrant left subclavian artery and left aortic arch remnant complex from the descending aorta in both dogs. This anomaly observed in both dogs is similar to an anomaly reported in humans, in which a persistent right aortic arch is found in conjunction with an aberrant left subclavian artery and a left aortic arch remnant (Kommerell's diverticulum). Surgical ligation and division of the left ligamentum arteriosum in both dogs, along with division of the left subclavian artery in the great Dane, resulted in resolution of clinical signs in both of the dogs in this report.     

Diagnosis of pulmonary thromboembolism in a cat using echocardiography and pulmonary scintigraphy

A 10-year-old male cat was presented with sudden onset of respiratory difficulties. Clinical examinatlon revealed an acute dyspnoea with cyanosis associated with a left systolic heart murmur. Standard thoracic radiographs excluded pulmonary oedema and showed very few pulmonary changes given the intensity of the respiratory compromlse. Echocardiographic examination revealed hypertrophic cardiomyopathy and a thrombus In the right pulmonary artery. Pulmonary sclntlgraphy confirmed a pulmonary thromboembolism with hypovascularisatlon of the left cranial lobe and of the ventral segment of the right lobe. Conservative treatment was instituted using an antibiotic (doxycycllne), anticoagulants (heparin, coumadine) and a calcium lnhlbitor (diltiazem). The cat was given absolute rest. The general condition of the animal improved.     

Pulmonary artery banding for ventricular septal defect in dogs and cats

Five dogs and 1 cat had pulmonary artery banding for ventricular septal defect and congestive heart failure. An umbilical tape band constricted the pulmonary artery to one-third its original diameter, increased the right ventricular pressure, and decreased the left ot right shunt. Five animals had remission of clinical signs; 1 dog died of right ventricular failure due to a band that had been applied too tightly. The results indicated pulmonary artery banding is helpful in reduction of clinical signs, due to increased flow to the lungs from ventricular septal defect.     

Chronic myocardial infarction due to arteriosclerosis of coronary arteries followed by acute thromboembolism of caudal abdominal aorta in a cat

A 10-year-old cat with the paresis of hind limbs was initially diagnosed as a hypertrophic cardiomyopathy followed by acute thromboembolism of caudal abdominal aorta from the findings of the medical examinations. However, this case was proved to be an chronic myocardial infarction due to arteriosclerosis of coronary arteries by the pathologic diagnosis. In the left ventricular, the hypertrophy and the narrowing were slight, and a coagulative infarction was seen obviously. The intramural coronary arteriosclerosis showed thickening of the wall due to medial hyperplasia by fibrosis, and arterial stenosis. Myocardial infarction and arteriosclerosis are scarcely any reports of these lesions in cats. This case is valuable for an extremely rare case of myocardial infarction in the cat.     

Pulmonary embolism and cor pulmonale in a cat

A 14-year-old male neutered cat experienced pulmonary embolism 15 days following surgical debridement of a recurrent dorsolumbar abscess. Clinical signs were dominated by respiratory distress. Pulmonary embolism was suggested from the lateral thoracic radiograph by the presence of an abruptly attenuated lobar artery and a contiguous oligaemic area in the caudal lung lobe. Pulmonary hypertension was demonstrated on Doppler echocardiography by right pulmonary artery dilation and tricuspid regurgitation raising the pulmonary arterial pressure to 56 mmHg. Chronic pulmonary hypertension, assumed from right ventricular wall hypertrophy, and hypokinesia, indicating chronic cor pulmonale, was suggestive of chronic rather than acute pulmonary embolism. Postmortem histological evidence of pulmonary arteriolar occlusion confirmed the diagnosis of pulmonary embolism.     

High mortality with severe dystrophic cardiac calcinosis in C3H/OUJ mice fed high fat purified diets

Severe degenerative myocardial disease occurred in female C3H/OUJ mice fed purified diets for 36 weeks; the diet contained 5% or 20% fat as non-hydrogenated soybean oil. Deaths of lactating females of this group (17/35 high fat diet and 7/35 low fat diet animals) were due to sudden cardiovascular collapse. Cardiomegaly with marked atrial and ventricular myocardial mineralization was seen at necropsy. Histologically, the random, myopathic foci were characterized by severe myocardial degeneration, mineralization, and fibrosis. Mural thrombosis, pulmonary arteriosclerosis, and mild myocardial inflammatory cell infiltrates were also present. Pathological changes were similar to those of dystrophic cardiac calcinosis, an incidental necropsy finding in certain mouse strains.     

Aberrant right subclavian artery causing megaoesophagus in three cats

Three entire, domestic, shorthair male cats (age range: 3 months to 5 years) were referred because of regurgitation. Megaoesophagus attributable to aberrant right subclavian artery, originating from the aorta at the level of the fourth intercostal space, was diagnosed in all cats using thoracic radiography and CT angiography. One cat had concurrent patent ductus arteriosus with a normal aortic arch. Three‐dimensional volume‐rendered CT images were used to assess the malformations and to plan surgery for the treatment of the vascular anomalies. Different surgical approaches were used in the two kittens. The third cat was not operated. CT angiography is well suited for preoperative planning in cats with aberrant right subclavian artery alone or in combination with other vascular anomalies.     

Pulmonary artery dissection causing haemothorax in a cat: potential role of Dirofilaria immitis infection and literature review

A 7-year-old male castrated domestic short-haired cat suddenly died. Gross examination revealed severe right-sided haemothorax with blood clots, four adult filarial nematodes in the blood clots and the caudal vena cava and haemorrhage dissecting into the tunica media of the right pulmonary artery. Histopathological investigation showed fibrosis of the tunica intima and disorganization/fragmentation of the elastic fibres accompanied by fibrous tissue deposition in the tunica media of both branches of pulmonary artery. Degenerative vasculopathy (intimal fibromuscular hyperplasia and medial hypertrophy/hyperplasia) involving pulmonary arteries was also observed. The polymerase chain reaction amplification and sequencing confirmed the identification of the parasite as Dirofilaria immitis. A diagnosis of pulmonary artery dissection with haemothorax and concomitant heartworm disease was formulated. Degenerative processes of the tunica media have been reported to cause pulmonary artery dissection in both humans and animals. Pulmonary artery remodelling induced by heartworms may be considered the underlying cause in the first case of feline pulmonary artery dissection, herein described.