Subcutaneous, abdominal, and thoracic encapsulated fat necrosis in bowhead whales Balaena mysticetus from Alaska, USA.

We describe a case series of encapsulated fat necrosis with subcutaneous, abdominal, and thoracic locations in 7 subsistence-harvested bowhead whales Balaena mysticetus. Masses had a variably-dense fibrous capsule surrounding necrotic adipocytes and calcium salts (saponification). One animal also had prior concussive injury, pleural fibrosis, and hepatic lipoma; the other animals had no significant findings. The described condition is uncommon in bowhead whales, with 7/575 (1.2%) observed from 1996 to 2015. The exact mechanisms of development of encapsulated fat necrosis in bowhead whales remain to be determined. Encapsulated fat necrosis has been reported in other baleen whales, humans, and cows. It is usually an incidental finding during post-mortem examination that needs to be differentiated from neoplastic and inflammatory lesions, as the latter may have public health implications. Assessment of further cases in bowhead whales and other baleen whales is warranted to better understand their pathogenesis.

Histopathological changes in the pancreas of cattle with abdominal fat necrosis.

The association between pancreatic disorder and abdominal fat necrosis in cattle remains unclear. The pancreases of 29 slaughtered cattle with or without fat necrosis were collected to investigate pathological changes. Japanese Black (JB) cattle were classified into the FN group (with abdominal fat necrosis; n=9) and N group (without fat necrosis; n=5). The pancreases were also collected from 15 Holstein Friesian (HF) cows. All JB cattle showed high body condition scores. Regarding the pathological findings, fatty pancreas which involves adipocyte infiltration into the pancreas and fat necrosis (saponification) were observed in 25 and 27 cases, respectively. Immunohistochemical staining with anti-Iba-1 antibody showed large numbers of macrophages surrounding the saponified fat in the pancreas. CD3-positive T cells were significantly more common in the pancreas of both the FN and N groups compared with the HF group (P<0.05). Furthermore, fibrosis in the pancreas exhibited a correlative tendency with the formation of necrotic fat mass in the peritoneal cavity (P<0.1). These results indicate that obesity leads to increased severity of pancreatic disorder, including fatty pancreas and pancreatitis. The pathological lesions in the pancreas may play a key role in abdominal fat necrosis through the inflammatory process.

Genetic relationships between internal diseases diagnosed at slaughter and carcass traits in Japanese Black cattle.

The objective of this paper was to estimate the genetic parameters of certain internal diseases (multifocal necrosis in the liver [MNL], bovine abdominal fat necrosis [BFN], and inflammation of the large intestine [ILI]) and to investigate relationships between the internal diseases and carcass traits (carcass weight [CW], rib eye area [REA], rib thickness [RT], subcutaneous fat thickness, and beef marbling score [BMS]). Records of the internal diseases and the carcass traits of 5,788 Japanese Black cattle were used for this study. The data for all the diseases were recorded as binary data as to whether the disease was observed (1) or not (0). Genetic parameters were estimated using linear and threshold animal models. The prevalence rates of MNL, BFN, and ILI were 16.1, 23.0, and 6.8%, respectively, and heritability estimates ± posterior SD were 0.18 ± 0.06, 0.28 ± 0.06, and 0.18 ± 0.06, respectively. The genetic correlations of MNL with BFN and ILI were -0.23 (P = 0.19) and -0.49 (P < 0.05), respectively. In contrast, the correlation between BFN and ILI was positive and high (0.96; < 0.05). The phenotypic correlations of the internal diseases with the carcass traits were weak and not different from 0 except for those of BFN and ILI with CW, REA, and RT, which were all negative (P < 0.05) and ranged from -0.21 (ILI and CW) to -0.05 (BFN and RT). The genetic correlations of MNL with the carcass traits were all weak and not significant. In contrast, the genetic correlations of BFN and ILI with CW, REA, and RT were all negative and significant (P < 0.05) between BFN and CW (-0.36) and between BFN and RT (-0.33). However, the genetic correlations for BFN and ILI with BMS were all positive at 0.21 P( = 0.16) and 0.39 (P < 0.05), respectively. The estimated heritability of the internal diseases suggests that they can be genetically improved. Genetic relationships of BFN and ILI with meat quantity traits were favorable for beef cattle breeding, because lower disease liabilities were associated with improved CW, REA, and RT for BFN and ILI. However, rather strong and unfavorable genetic relationships were found between BFN or ILI and BMS, which is related to meat quality. This suggests that selection for animals with superior BMS would increasingly lead to animals with higher liability to the internal diseases.

Effects of clay on fat necrosis and carcass characteristics in Japanese Black steers.

Twenty 10-month-old Japanese Black steers were used to evaluate the effects of clay on fat necrosis and carcass characteristics. Ten steers (Clay group) were fed the clay (50 g/day) during 10-30 months of age. The other 10 steers (Control group) were not fed it. There was no significant difference in body weight or average daily gain between the two groups (P > 0.05). The occurrence of fat necrotic mass in the Clay group (30%) was lower (P < 0.05) than that in the Control group (90%) at slaughter. The size of necrotic masses in the Clay group was smaller (P < 0.05) than that in the Control group. There was no significant difference in the marbling score, beef color, Longissimus muscle area or subcutaneous fat thickness between the two groups. These results suggest that the clay prevented the occurrence of fat necrosis and did not affect the carcass characteristics in Japanese Black steers.

Diagnostic ultrasonography in cattle with abdominal fat necrosis.

This study describes the ultrasonographic findings in 14 cows with abdominal fat necrosis. Ultrasonography of the abdomen revealed the presence of heterogeneous hyperechoic masses and hyperechoic omentum with localized masses floating in a hypoechoic peritoneal fluid. A hyperechogenic rim was imaged around both kidneys. The intestines were coated with hyperechoic capsules and the intestinal lumens were constricted. Ultrasonographic examination of the pancreatic parenchyma showed an overall increased echogenicity which was homogenously distributed in 3 cases. A diagnosis of abdominal fat necrosis was made with ultrasound-guided biopsy of the echogenic masses, and thereafter at postmortem examination. Results from this study demonstrate the efficacy of ultrasonography as an imaging modality for antemortem diagnosis of abdominal lipomatosis in cattle. To the authors' knowledge, this study is the first that illustrates ultrasonographic findings in cattle affected with abdominal lipomatosis.

Fat necrosis simulating recurrent neoplasia following external beam radiotherapy in a dog.

A 4.5-year-old neutered male dog was diagnosed with incompletely excised well-differentiated lymphangiosarcoma in the right inguinal subcutaneous region. The mass had metastasized to the right hypogastric and medial iliac lymph nodes. Surgery followed by definitive radiation therapy was administered to the primary site and the sites of metastasis. The dog had a complete response to radiotherapy, and minimal acute side effects. Doxorubicin was administered after radiotherapy. Approximately 4 months following radiation therapy, the dog developed a mass, presumed recurrent tumor, in the original site. In a biopsy only steatitis and fibrosis were found. The mass continued to grow and conservative surgical excision was elected. Histopathologically the diagnosis was fat necrosis and steatitis, with a microscopic focus of lymphangiosarcoma. Fat necrosis is an uncommon sequelum to breast irradiation in people and also appears to be rare in animals. Fat necrosis should be considered as a differential diagnosis when recurrent tumor is suspected in a previously irradiated subcutaneous site in a dog.

Characterization of the anemia of inflammatory disease in cats with abscesses, pyothorax, or fat necrosis.

The purpose of this study was to describe the anemia of inflammatory disease (AID) in cats with naturally-occurring inflammatory diseases, such as abscesses (n = 12), pyothorax (n = 6), and fat necrosis (n = 3). Exclusion criteria were positive FeLV/FIV tests, neoplasia, nephro-, hepato- or endocrinopathies, and blood loss anemia. CBC, clinical biochemistry, measurements of serum erythropoietin, iron, total iron-binding capacity (TIBC), ferritin, acute phase proteins, erythrocytic osmotic fragility (OF), and Coombs' tests were performed. A decrease in hematocrit of 1-28% (median, 10%) occurred within 3-16 days (median, 8 days). The anemia was mild (n = 11), moderate (n = 8), or severe (n = 2). In most cases it was normocytic normochromic, non-regenerative (n = 18), or mildly regenerative (n = 3). Sixteen cats had leukocytosis and 5 mild hyperbilirubinemia. The Coombs' test results were negative for 8 cats and positive for 1 cat. OF was increased in 2 out of 14 cats. Hypoalbuminemia (n = 18) and hyperglobulinemia (n = 16) resulted in a lowered albumin/globulin-ratio in 19 cats. Iron and TIBC were low in 2/19 and 6 /19 cats, respectively. The ferritin concentrations were normal in 7 cats and increased in 12 cats. The acute phase proteins alpha1-acid-glycoprotein and haptoglobin were increased in 14/14 and 13/14 cats, respectively. Erythropoietin was normal (n = 4), mildly increased (n = 7) or severely increased (1). Two cats were euthanized due to their underlying disease, 3 cats needed blood transfusions. AID in cats is usually mild to moderate, non-regenerative, and normocytic normochromic. It can be clinically relevant causing severe and transfusion-dependent anemia. AID seems to be multifactorial with evidence of iron sequestration, decreased RBC survival, and insufficient erythropoietin production and bone marrow response. Specific and supportive therapy, including transfusions, can reverse these processes.

Diffuse mesenteric lipodystrophy (massive fat necrosis) in a cat.

Clinical, radiographic, and pathological findings of diffuse mesenteric lipodystrophy in a 3-year-old, female domestic short-haired cat are described. The animal had fallen from a height of approximately 20 metres 6 weeks previously, after which it developed respiratory distress and anorexia. The cat was thin, exhausted and had rapid, shallow, open-mouthed breathing. Serial upper gastrointestinal contrast radiographs showed a prolonged transit time of the contrast medium due to restricted gastric emptying, and filling defects of the duodenojejunal portions of the small intestines. The cranial abdominal cavity contained large, firm, white masses that adhered to most of the anterior abdominal organs. The intestinal walls were completely surrounded by large, hard, lobulated masses of lipomatous tissue. The masses were characterised histologically by extensive areas of coagulative necrosis of adipocytes containing foci of saponification. The lesions resembled those of massive fat necrosis or lipomatosis in cattle, pigs and deer.

Intrathoracic lipoma in a Labrador retriever.

Pyrexia, granulocytosis and hyperglobulinaemia were the main clinical findings in an unusual case of intrathoracic lipoma in a 12-year-old male Labrador retriever. The response to antibiotic and anti-inflammatory treatment was poor, prompting further investigation. Survey radiographs and ultrasonography revealed a cavitated, fluid-filled soft tissue mass in the right hemithorax, which was successfully removed resulting in rapid resolution of clinical signs. Lipomas are rare intrathoracic extrapulmonary tumours. Previously reported clinical signs are dyspnoea and coughing, attributed to the mass effect of the lipoma. The unusual presentation in this case was caused by necrosis of the lipoma, probably owing to torsion of the pedicle attaching it to the cranial mediastinum.

Nodular fat necrosis in the feline and canine abdomen.

The radiographic appearance of nodular fat necrosis is described in ten cats and one dog. The most common radiographic sign was the presence of a focal mineralized circular to oval soft tissue mass in the abdominal fat as present in 9 cats. These masses had a distinct eggshell-like rim encapsulating the lesion. In one cat and one dog multiple masses were present, without radiographic signs of mineralization. Abdominal ultrasound was performed in three cats and one dog, findings included the presence of hyperechoic masses with associated acoustic shadowing, some with a hypoechoic centre. Almost all animals were old and obese. In three cats and one dog, changes were confirmed with biopsy or post mortem examination. Lesions having the appearance of those in this paper are most likely incidental findings and should not be confused with abdominal masses of neoplastic origin. Ultrasound can be helpful in identifying such lesions.

Serum apolipoprotein B-100 concentrations in healthy and diseased cattle.

The purpose of this study was to establish the normal range of serum apolipoprotein B-100 (APO B-100) concentration in clinically normal cattle, and to assess its abnormalities with clinical diseases. We measured the serum concentration of APO B-100 in cattle of varying ages, breeds and sex, maintained under normal field conditions. Blood samples were obtained from 735 apparently healthy cattle and 146 cows with various diseases. The concentration of serum APO B-100 in cattle was assayed by the single radial immunodiffusion method. The concentration of serum APO B-100 in healthy adult breeding bulls (mean +/- SD: Holstein; 101 +/- 46 microg/ml, Japanese Black; 106 +/- 46 microg/ml) was significantly (P<0.001) lower than that in cows (Holstein; 259 +/- 63, Japanese Black; 210 +/- 46 microg/ml), while that of APO B-100 in steers (Holstein; 290 +/- 86 microg/ml, Japanese Black; 302 +/- 90 microg/ml) was similar to the level in cows. The concentration of serum APO B-100 in cattle varied with sex and breed. APO B-100 concentration in cattle was decreased in association with metabolic disorders such as ketosis, displaced abomasum and fatty liver. From these results, it is assumed that the level of serum APO B-100 will be applied to diagnosis of metabolic diseases in cattle.

Lipogenic and lipolytic activities in isolated adipocytes from cattle with fat necrosis.

The metabolic activity and cellularity of adipocytes isolated from the abdominal adipose tissue of normal heifers and heifers with fat necrosis were compared. The basal rate of U-14C glucose incorporation into total lipids in adipocytes from the periphery of the necrotic mass was higher than that in the colonic mesentery of both the affected and normal heifers. In the affected animals. adipocytes from the mesentery of the spiral colon and adipocytes from the periphery of the necrotic mass failed significantly to increase the incorporation of labelled acetate and glucose, respectively, in response to insulin. In the presence of adrenalin, adipocytes from the colonic mesentery and the periphery of the necrotic mass of the affected heifers released more glycerol than adipocytes from the colonic mesentery of normal animals. In addition, the mean diameters of adipocytes from the colonic mesentery and the periphery of the necrotic mass of the affected heifers were significantly greater than those from the colonic mesentery of normal animals. These results indicate that excessive fattiness in abdominal adipose tissue may predispose cattle to fat necrosis.

Lipoprotein lipase activity of post-heparin plasma in Japanese black cattle affected with fat necrosis.

Post-heparin plasma (PHP) lipoprotein lipase (LPL) activity and serum lipoprotein concentration were examined in Japanese Black cows affected with fat necrosis. The PHP-LPL activity in the affected cows was significantly (P < 0.001) higher than in normal animals and tended to reduce 4 weeks after treatment with isoprothiolane. This finding indicates that affected cows have a predisposition to deposit more fat into adipose tissue than normal animals. The serum concentrations of triglyceride in beta-lipoprotein and of cholesterol, phospholipid and total lipid in alpha-lipoprotein were significantly (P < 0.05) lower in the affected cows. Elevated levels of phospholipid and total lipid in alpha-lipoprotein as well as decreased levels of non-esterified fatty acid (NEFA) were observed after medication. It is suggested that isoprothiolane produces an improvement in hepatic lipid metabolism including acceleration of plasma NEFA uptake and alpha-lipoprotein secretion in affected cows.

Effects of isoprothiolane and phytosterol on lipogenesis and lipolysis in adipocytes from rats of dietary fat necrosis.

To study effects of isoprothiolane and phytosterol on dietary fat necrosis, 3 groups of rats were fed hardened-tallow (HT) diet. Two groups of rats received either isoprothiolane (50 mg/kg) or phytosterol (20 mg/kg) orally once a day consecutively for 10 weeks. One group of rats received standard diet (CE-2) as a control. Fat necrotic lesions were observed in epididymal and perirenal adipose tissues from all rats in the 3 groups fed HT diet. Rats with fat necrosis were characterized by visceral type obesity and saturation in fatty acid composition of triglyceride in adipose tissue. The highest glucose conversion to total lipids was seen in adipocytes from the rats given phytosterol. There was no lipolytic response to epinephrine stimulation (1-100 microM) in adipocytes from the rats given only HT diet, while similar response of adipocytes from the 2 groups treated with either drug to those from the rats fed standard diet was observed. The levels of total saturated fatty acids of phospholipid in adipose tissue from the rats given either drug were lower than that of the rats given only HT diet. These data suggest that either drug alters fatty acid composition of phospholipid in fat cell membrane and enhances lipolysis of the cells.