Ultrasonographic findings in a cow with ascites due to thrombosis of the caudal vena cava.

This case report describes a three-year-old Swiss Braunvieh cow with ascites due to thrombosis of the caudal vena cava. Ultrasonography verified the ascites and revealed dilatation of the abdominal portion of the caudal vena cava (4.8 cm). It was presumed that the caudal vena cava was occluded by a thrombus or by perivenous compression cranial to the dilatation. Post mortem findings included: a massive accumulation of fluid in the abdominal cavity; a 15 cm long thrombus in the subphrenic region of the caudal vena cava; multiple pulmonary abscesses; severe thrombosis of the pulmonary vasculature; hepatic congestion; oedematous abomasal folds; and severe thrombophlebitis of the left jugular vein and both udder veins, due to poor intravenous injection technique. Ascites caused by thrombosis of the caudal vena cava is rare because collateral routes of venous return, including the udder veins, are usually established. It was therefore concluded that the ascites was attributable to bilateral thrombosis of the udder veins.     

Caudal vena cava thrombosis-like syndrome in a horse

A 9-year-old Quarter horse was presented for chronic refractory pneumonia. On necropsy, an hepatic abscess, caudal vena cava thrombosis, pulmonary thromboembolism, and embolic pneumonia were identified. Similar lesions have been reported in cattle as caudal vena cava thrombosis syndrome, however this syndrome has not previously been reported in horses.     

Clinical findings and diagnosis of thrombosis of the caudal vena cava in cattle

This paper describes the causes, clinical findings and diagnosis of caudal vena caval thrombosis in cattle. Occlusion of the vein is caused by a 'white' thrombus, and typical clinical signs include chronic weight loss, poor general condition and intermittent fever. Most affected cattle have respiratory signs; in some, pulmonary haemorrhage, ascites and sudden death occur. Haematological analyses, endoscopy of the respiratory tract and ultrasonographic examination of the pleura, liver and abdomen should be carried out in cattle suspected of having thrombosis of the caudal vena cava. The most important diagnostic finding is dilatation of the caudal vena cava seen via ultrasonography. Normally, the caudal vena cava appears triangular in cross section but in cattle with thrombosis it is oval or circular. The prognosis is poor and there is no treatment.     

Ultrasonographic findings in three cows with chronic ragwort (Senecio alpinus) poisoning

Three cows with regwort (Senecio alpinus) poisoning were examined clinically, haematologically and ultrasonographically, and biopsy specimens of the liver were examined histologically. At the end of the study, the cows were euthanased and examined postmortem. The major clinical signs included severely disturbed general demeanour and behaviour, and severe diarrhoea. One cow was photosensitive. The activities of liver enzymes and the concentration of bilirubin were high in all of the cows. In two of the cows, ultrasonographic examination revealed a heavy accumulation of abdominal fluid, which was diagnosed as non-inflammatory ascites. In all the cows, the liver parenchyma was heterogeneous, and cows 1 and 2 had multiple echogenic foci 5 to 10 mm in diameter. In cow 3, the facies diaphragmatica of the liver appeared irregular in outline owing to the presence of nodules which were approximately 5 cm in diameter. The liver was also greatly enlarged and extended almost to the linea alba ventrally and beyond the reticulum cranially. All the cows had portal hypertension and the portal vein was dilated, resulting in oedema of the walls of the gall bladder, the small intestines and the omentum. The diameter of the caudal vena cava was reduced as a result of the impaired hepatic circulation. Histological examination of liver biopsy specimens revealed severe hepatic fibrosis in all the cows.     

Cushing's disease complicated with thrombosis in a dog

Thrombosis is a potential complication of hyperadrenocorticism (HAC) in dogs. An 8-year-old male Beagle diagnosed with pituitary-dependent HAC had complicated with thrombosis in the caudal vena cava and abdominal aorta, which was treated by hypophysectomy and antithrombotic therapy. After hypophysectomy, hypercortisolemia disappeared and the general condition was also significantly improved. Ultrasonography after hypophysectomy revealed that the thrombus remained in the abdominal aorta, but the thrombus in the caudal vena cava had disappeared. However 692 days after the hypophysectomy, the dog had an acute onset of dyspnea and died. Postmortem examination revealed the presence of thrombi in the abdominal aorta and the pulmonary artery. Observations from this case show that HAC dogs must be attention to thrombosis.     

Thrombosis of the caudal vena cava presenting as an unusual cause of an abdominal mass and thrombocytopenia in a dog

Thrombosis of the caudal vena cava in a dog secondary to metastatic neoplasia is described. The dog had a palpable abdominal mass and persistent thrombocytopenia due to a thrombosed caudal vena cava that was surgically removed. A few days after its removal, the dog died and neoplastic cells of neural crest origin were identified at the edge of the thrombus. Massive thrombosis can be an unusual cause of platelet consumption, leading to thrombocytopenia and disseminated intravascular coagulation. Deep vein thrombosis of the vena cava can occur in dogs and may mimic an abdominal mass. Multiple mechanisms may be involved in the development of venous thrombosis, including endothelial damage by neoplastic cells and the presence of a hypercoagulable state secondary to neoplasia. Extensive collateral circulation may allow removal of diseased vena cava.     

Liver abscesses in Holstein dairy cattle: 18 cases (1992-2003)

BACKGROUND: The characteristic clinical manifestations, clinicopathologic findings, treatment, and outcome of dairy cattle with liver abscess are poorly defined. ANIMALS: The study included 18 Holstein cows with liver abscesses. METHODS: A retrospective study of medical records was performed. Cattle with liver abscess were identified by ultrasound examination or exploratory laparotomy. RESULTS: The most common reason for examination was anorexia (14/18). Five cows had fever, 5 were bradycardic, and 5 were tachycardic. Peritonitis (n=6) and vagal indigestion (n=4) were the most frequently associated diseases. Neutrophilia (n=14), hyperfibrinogenemia (n=11), and high serum globulin concentration (n=10) were characteristic of chronic inflammation. Evidence of liver disease on serum biochemistry profile was uncommon. The most common bacterium isolated from the abscess was Arcanobacterium pyogenes (n=4). Anaerobic bacteria were isolated frequently (n=7). There were 6 polymicrobial isolates, with both aerobic and anaerobic bacteria, out of 8 positive samples. Medical treatment was successful in 5 of 7 cattle. Five cows were euthanized and postmortem examination revealed 2 cattle with thrombosis of caudal vena cava. CONCLUSIONS AND CLINICAL IMPORTANCE: Holstein dairy cattle affected by liver abscess exhibit no pathognomonic clinical signs. Clinicopathologic findings were often consistent with a chronic active inflammation. Liver abscesses should be included in the differential diagnosis in cattle with a chronic inflammatory process, cranial peritonitis, or vagal indigestion. Prolonged treatment with antimicrobials might be successful.     

Ultrasonographic characteristics of abdominal and thoracic abscesses in cattle and buffaloes

Six cows and five buffaloes with abdominal and thoracic abscesses were examined clinically and ultrasonographically. There was a wide range of clinical signs and at least 50% of the animals exhibited dull demeanour, anorexia, abdominal pain, recurrent tympany and/or weight loss. Three cases of abdominal abscesses were imaged in the left ventral abdomen between the rumen and abdominal wall, two cases were imaged at the xiphoid cartilage near the reticular wall and one case was imaged on the right ventral abdomen between the jejunum and right abdominal wall. Four cases of thoracic abscesses were imaged in the third intercostal space on the left side; however, one case of abscess was imaged in the fourth intercostal space, also on the left side. The content of the abscess was echogenic in eight animals and anechoic in three. In three animals, the content of the abscess was partitioned by echogenic septae. In two cows, the echogenic content of the abscess was surrounded by a narrow rim of anechoic fluid. The diameters of the abscesses were 5-10 cm in three cows, 11-15 cm in seven cows and >15 cm in one cow. In every case, the diagnosis was confirmed by centesis and aspiration of the abscess, which yielded purulent material. There were biochemical data of hypoalbuminaemia and hyperglobulinaemia and 90% of tested animals had neutrophilia. Five cows were examined at slaughter, where the ultrasonographic diagnosis was confirmed.     

ULTRASONOGRAPHIC DIAGNOSIS: CRANIAL VENA CAVA THROMBOSIS IN A COW

A 5-year-old Hereford cow was donated to Oregon State University, College of Veterinary Medicine. Two weeks before presentation the cow was treated by a left-flank laparotomy to correct a uterine torsion that revealed an excessive amount of abdominal fluid and a full term dead fetus. Ultrasonographic evaluation of the right cranioventral thoracic cavity was performed owing to physical examination (muffled heart sounds, areas of silence) and thoracocentesis findings suggestive of pleuritis. Ultrasonography revealed hypoechoic pleural effusion and a mass of mixed echogenicity visible within the right atrial lumen extending into the cranial vena cava. A diagnosis of cranial vena cava thrombosis was demonstrated at necropsy. The clinical, ultrasonographic, and pathological features of this less common condition (cranial vena cava thrombosis) in cattle are discussed.     

Caudal vena caval thrombosis following treatment of deep digital sepsis

A diagnosis of caudal vena caval thrombosis was made by ultrasonography of a Holstein cow presented for lethargy and poor milk production. Medical treatment was unsuccessful and the cow was euthanized. The diagnosis was confirmed at necropsy and Fusobacterium necrophorum was isolated from the thrombus. This paper discusses potential novel sources of caval thrombosis in this case.     

Ultrasonographic measurement of caudal vena cava to aorta ratios for determination of volume depletion in normal beagle dogs

A noninvasive method for quantifying hydration status would be helpful for clinical management and for research applications in dogs. This prospective, experimental, pilot study aimed to assess the feasibility of ultrasonographic measurement of the caudal vena cava to aorta ratio as a method for quantifying volume depletion in dogs. In 12 normal beagle dogs, furosemide was administered intravenously at a dose of 1 mg/kg, every 2 h, for 8 h, to induce consecutive volume depletion. Every 30 min after administration, ultrasonographic images of the caudal vena cava and aorta, and physical and biological parameters related to dehydration were acquired. On transverse and longitudinal planes of caudal vena cava and aorta images, the height and area of the caudal vena cava and aorta were measured to calculate the caudal vena cava/aorta ratios. All images were acquired by approaching from the right intercostal space with the dogs in left lateral recumbency. A negative correlation was present between the percentage of weight loss in dogs and all four investigated caudal vena cava/aorta ratios (transverse plane width of the caudal vena cava [TW]/aorta; transverse plane height of caudal vena cava [TH]/aorta; longitudinal plane area of the caudal vena cava [TA]/aorta; and longitudinal plane maximal height of the caudal vena cava [L]/aorta). Significant differences (P < 0.001) were seen between dogs with and without clinical signs of dehydration for all caudal vena cava/aorta ratios. Findings indicated that ultrasonographic caudal vena cava/aorta ratios are feasible methods for quantifying volume depletion and for use as an adjunct to standard subjective methods for estimating hydration status in dogs.     

Effect of prostaglandin F2 alpha on hormone concentrations in dairy cows after parturition

This study was designed to evaluate the effects of exogenous prostaglandin F2 alpha (PGF2 alpha) on hormone secretion in cows without a corpus luteum. Blood samples were taken from 10 Friesian dairy cows at frequent intervals from a jugular vein and the caudal vena cava starting between nine and 20 days after parturition. PGF2 alpha (25 mg dinoprost) was injected intramuscularly into five cows after the first eight hours of sampling. Plasma concentrations of 13,14-dihydro 15-keto PGF2 alpha (PGFM) increased rapidly but had returned to baseline by 14 hours after injection. There was no significant effect of the treatment on the time taken by the cows to resume ovarian cycles, and it had no consistent effect on plasma luteinising hormone (LH) patterns; however the amplitude of pulses of LH was temporarily suppressed in two cows and the frequency of pulses of LH was immediately increased in one cow. Treatment with PGF2 alpha had no significant effect on the concentration of oestradiol in blood from the vena cava. It is concluded that any enhancement of the reproductive performance of cows treated with PGF2 alpha after parturition is not due to a direct effect on pituitary-ovarian function.     

Two-year study of bovine hepatic abscessation in 10 abattoirs in County Cork, Ireland

The livers from 6337, 12- to 16-month-old heifers slaughtered in 10 domestic abattoirs over a period of two years were examined; 368 (5.8 per cent) had gross lesions, of which 120 (1.9 per cent) had abscesses, 74 (1.17 per cent) had only scarring, and 44 (0.7 per cent) had telangiectasis (so-called 'sawdust' liver). Of the 120 livers in which abscesses were detected, 53 (44 per cent) had a single large abscess (>4 cm diameter), 44 (36.6 per cent) had a single small abscess (<4 cm), and 23 (19 per cent) had more than two abscesses; in 20 of them (16.6 per cent) the abscesses were resolving, and in 10 (8.3 per cent) the abscesses were ruptured. Forty-three (35.8 per cent) of the livers with abscesses had adhesions to the diaphragm and diaphragmatic lung lobes, three (2.5 per cent) had adhesions to other abdominal organs, 12 (10 per cent) also had scarring and two (1.7 per cent) also had lesions due to liver fluke. There was no significant association between the liver fluke lesions and the abscesses. In 46 (38.3 per cent) of the livers the abscesses were located in the mid-dorsal diaphragmatic or dorsocranial area of the liver; 28 (23.3 per cent) were adjacent to the posterior vena cava and could as a result have caused thromboembolic disease. Clinical signs attributable to the abscesses were observed in only one animal.     

Ultrasonographic examination of the liver in cows

The size of the liver, as well as the situation and diameter of vessels in cattle were determined by use of ultrasonography. Ultrasonographic examinations of the liver were performed on 10 cows 10 times within 2 weeks, using a 3.5-MHz linear transducer on the right side in the 12th, 11th, and 10th intercostal spaces. Dorsal and ventral margin of the liver as well as localization and diameter of the caudal vena cava and the portal vein were determined in each intercostal space. Furthermore, the angle of the liver in the ventral area between the visceral surface and the diaphragmatic surface, the dorsal margin, and the circumference of the gall bladder were determined. The ultrasonographic values of liver size and localization in healthy cows can be used as reference values for the diagnosis of changes in liver size attributable to illness.     

49-month survival following caval venectomy without nephrectomy in a dog with a pheochromocytoma

An 11 yr old spayed female Labrador retriever was diagnosed with a right adrenal tumor. At surgery, adhesions to the right kidney were dissected, allowing the right kidney to be preserved. The tumor showed extensive invasion into the suprarenal vena cava. It was felt that thrombus removal via venotomy could not be performed. Instead, the vena cava was ligated caudal to the liver and cranial to the right renal vein. The neoplastic gland was then excised en bloc together with the portion of the invaded caudal vena cava. Hind limb edema had developed preoperatively and increased transiently in the first days postoperatively. The animal was discharged 6 days postoperatively with no other clinical disorders, and hind limb edema resolved over time. Histopathology identified a pheochromocytoma. The dog died 49 mo later. A neoplastic thrombus of the vena cava may require venotomy to allow thrombus removal. Occasionally, removal of the thrombus by venotomy may prove impossible. In such a situation, en bloc removal of the concerned portion of the vena cava may be performed with a good long-term outcome provided that gradual occlusion of the vena cava by the thrombus has allowed time for collateral circulation to develop.     

Extensive venous thrombosis and hind-limb edema associated with adrenocortical carcinoma in a dog.

A 10-year-old, spayed female, mixed-breed dog was referred for evaluation of bilateral hindlimb edema and weakness. Abdominal ultrasonography showed increased echogenicity of the lumen of the caudal vena cava from the level of the urinary bladder to the level of the cranial pole of the right kidney. Bilateral saphenous venograms displayed numerous filling defects in the caudal vena cava, right external iliac vein, right femoral vein, and the right common iliac vein. Extensive venous thrombosis was diagnosed, and the animal was euthanized. Necropsy confirmed the presence of venous thrombosis and revealed a right adrenocortical carcinoma that had invaded the caudal vena cava.     

Extensive caudal vena cava thrombosis secondary to unilateral renal tubular cell carcinoma in a dog

A nine-year-old German shorthaired pointer cross was admitted because of partial anorexia, exercise intolerance and haematuria. On clinical examination, subcutaneous oedema, purpura and ascites were detected along with a palpable mass in the right craniodorsal abdomen. Laboratory findings included regenerative anaemia, leucocytosis, thrombocytopenia, azotaemia, increased blood serum alkaline phosphatase and proteinuria. Radiographic and ultrasonographic examinations revealed a large neoplasm involving the right kidney. Computed tomography further showed that the neoplastic tissue had spread into the lymph nodes, the wall of the caudal vena cava, the liver and lungs. The right renal vein, caudal vena cava and iliac veins appeared enlarged and secondarily thrombosed. A diagnosis was made of renal tubular cell carcinoma with secondary venous thrombosis. Gross postmortem examination confirmed the imaging findings, while light and electron microscopic examination revealed that the neoplasm was a solid carcinoma originating from the proximal convoluted renal tubules.     

Caudal vena cava kinking in dogs with ascites

A 9-year-old dog with spontaneous ascites was found to have hepatic vein distension and a tortuous vena cava on abdominal ultrasound. In right lateral recumbency, the caudal vena cava crossed the diaphragm and became kinked before entering into the right atrium. Following this observation, we performed an experimental study in a normal dog to determine whether kinking of the caudal vena cava could be the result and not the cause of ascites. Ascites was induced using warm saline injected through a needle inserted into the abdominal cavity. Venograms were collected from different body positions, under four conditions: before and after a total of one, two and 3 liters of saline had been injected. Caudal vena cava kinking was observed in the experimental dog after 2 liters of fluid had been injected. Vena cava obstruction may cause ascites, but we found that sometimes caudal vena cava kinking can be the result and not the cause of the peritoneal effusion.     

Computed tomographic and magnetic resonance imaging features of canine segmental caudal vena cava aplasia

O bjective : To describe the computed tomographic and magnetic resonance imaging features of segmental caudal vena cava aplasia and associated vascular anomalies in dogs.
M ethods : A retrospective study was performed reviewing computed tomographic and magnetic resonance imaging archives of eight institutions for dogs with segmental caudal vena cava aplasia. Inclusion criteria included a computed tomographic or magnetic resonance imaging study and supportive diagnostic and follow-up information. Abdominal vessels were reviewed for size, shape, location and course (including tributaries and branches) and classified as normal, abnormal or shunt vessels.
R esults : Ten dogs with segmental caudal vena cava aplasia were identified. In all dogs, postrenal caval blood was shunted to either a right or a left azygos vein, with seven different angiographic patterns. Affected dogs were predominantly female (70 per cent) and young (mean 2·6 years). Additional portocaval and porto-azygos shunt vessels were identified in two cases each. Computed tomographic angiography and magnetic resonance angiography depicted details of abdominal vessels including thrombus formation in one dog.
C linical S ignificance : Segmental caudal vena cava aplasia is a vascular congenital anomaly in the dog that can be associated with thrombosis and portosystemic shunts. Computed tomographic angiography and magnetic resonance angiography are excellent tools to demonstrate the complex vascular anatomy and to guide treatment planning for portosystemic shunts and thrombolytic therapy.     

Pericardial ectopic liver in a cat

An aged domestic short-haired cat was presented for examination because of a six week history of weight loss, diarrhoea, and increased appetite. Clinical examination revealed the cat to be emaciated, icteric and the liver was enlarged. Laboratory tests confirmed the presence of hepatic disease and radiographic examination showed hepatomegaly and ascites together with an enlarged globular heart. Ultrasonography showed a heart of normal size surrounded by tissue and/or fluid within the pericardial sac. Following euthanasia, necropsy revealed the presence of ectopic hepatic tissue within the pericardial sac. Both normally positioned liver and the intrapericardial hepatic tissue showed chronic active pericholangitis and nodular hyperplasia. There was no evidence of a diaphragmatic peritoneal-pericardial hernia, but the intrapericardial mass was connected to the liver by a thin cord of tissue ventral to the caudal vena cava.