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The relation of amyloidosis to social stress induced by crowding in the Syrian hamster (Mesocricetus auratus)



The aim of the presented study was the investigation of a probable influence of social stress on spontaneous amyloidosis. As stress-inducing parameter crowding of the animals was used. 220 Syrian hamsters were kept individually (controls) or with 3, 5, 7 animals per cage. The crowded animals showed a significant decrease in mean survival time. This was linked to a histopathological examined significant increase in the extent and incidence of amyloidosis in several organs of both male and female hamsters. The kidneys and adrenals were most affected. Chronic inflammation as one probable amyloidosis-inducing factor, was not related to the observed morphological alterations. Furthermore the increase of amyloidosis was statistically not connected with an age-dependent development of amyloidosis. Amyloidosis in Syrian hamsters may be not a mere phenomenon of aging and age-related decline of the immune system but rather the results of a complex set of variables, including factors of social environment and social interactions that continuously put stress on the hamsters.
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... Moreover, stress has been proposed as a factor in development of amyloidosis in some species (Cowan and Johnson, 1970;Germann et al., 1990;Papendick et al., 1997). The tissue tropism of amyloid deposition in affected camels was similar to that reported in other species (DiBartola and Benson, 1989). ...
... The grouping of animals leads to an increase in temperature, reducing the energy expenditure necessary to maintain body temperature, which results in a positive energy balance. Moreover, the grouping may cause stress to the animals because hamsters live alone under natural conditions[6,18]. Foster et al.[15]found that hamsters subjected to stress showed statistically increased food intake, weight gain and adiposity. ...
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Although obesity is well established in hamsters, studies using diets with high levels of simple carbohydrate associated with lipids are necessary to assess the impact of this type of food in the body. In this studya high sugar and butter diet (HSB) and high temperature were employed towards this end. Obesity was successfully induced at a temperature of 30.3?C to 30.9?Cafter 38 days feeding the animals an HSB diet.It was shown that although diet is important for the induction of obesity, temperature is also essential because at a temperature slightly below the one required, obesity was not induced, even when the animals were fed for a longer period (150 days).The obese clinical condition was accompanied by biochemical and hematological changes, as increased cholesterol and triglyceride levels and increased leukocyte numbers, similar to alterations observed in obese humans. Furthermore, it was demonstrated that increasing the intake of simple carbohydrates associated with lipids provided evidence of inflammation in obese animals.
... 45,52 Additionally, the social stress of crowded housing is associated with AA amyloidosis in Syrian hamsters and mice in the laboratory setting. 13,22 Thus, captive foxes may experience enhanced SAA transcription from stress-induced glucocorticoid production that could promote amyloidosis. ...
Systemic amyloid A (AA) amyloidosis is highly prevalent (34%) in endangered island foxes (Urocyon littoralis) and poses a risk to species recovery. Although elevated serum AA (SAA) from prolonged or recurrent inflammation predisposes to AA amyloidosis, additional risk factors are poorly understood. Here we define the severity of glomerular and medullary renal amyloid and identify risk factors for AA amyloidosis in 321 island foxes necropsied from 1987 through 2010. In affected kidneys, amyloid more commonly accumulated in the medullary interstitium than in the glomeruli (98% [n = 78 of 80] vs 56% [n = 45], respectively; P < .0001), and medullary deposition was more commonly severe (19% [n = 20 of 105]) as compared with glomeruli (7% [n = 7]; P = .01). Univariate odds ratios (ORs) of severe renal AA amyloidosis were greater for short- and long-term captive foxes as compared with free-ranging foxes (ORs = 3.2, 3.7, respectively; overall P = .05) and for females as compared with males (OR = 2.9; P = .05). Multivariable logistic regression revealed that independent risk factors for amyloid development were increasing age class (OR = 3.8; P < .0001), San Clemente Island subspecies versus San Nicolas Island subspecies (OR = 5.3; P = .0003), captivity (OR = 5.1; P = .0001), and nephritis (OR = 2.3; P = .01). The increased risk associated with the San Clemente subspecies or captivity suggests roles for genetic as well as exogenous risk factors in the development of AA amyloidosis.
A high prevalence of AA-amyloidosis was identified in a breeding colony of northern tree shrews ( Tupaia belangeri) in a retrospective analysis, with amyloid deposits in different organs being found in 26/36 individuals (72%). Amyloid deposits, confirmed by Congo red staining, were detected in kidneys, intestines, skin, and lymph nodes, characteristic of systemic amyloidosis. Immunohistochemically, the deposited amyloid was intensely positive with anti-AA-antibody (clone mc4), suggesting AA-amyloidosis. The kidneys were predominantly affected (80%), where amyloid deposits ranged from mild to severe and was predominantly located in the renal medulla. In addition, many kidneys contained numerous cysts with atrophy of the renal parenchyma. There was no significant association between concurrent neoplastic or inflammatory processes and amyloidosis. The lack of distinctive predisposing factors suggests a general susceptibility of captive T. belangeri to develop amyloidosis. Clinical and laboratory findings of a female individual with pronounced kidney alterations were indicative of renal failure. The observed tissue tropism with pronounced kidney alterations, corresponding renal dysfunction, and an overall high prevalence suggests amyloidosis as an important disease in captive tree shrews.
Hamsters and gerbils belong to the order Rodentia and lives in relatively arid environments and both are extremely popular as pets. Hamsters and gerbils are also being used in clinical research across the globe and knowledge of their basic anatomy and physiology is of extreme importance in providing adequate care of these species. Hamsters and Gerbils commonly present for a variety of conditions which are discussed in this chapter. GI diseases, neurological and dermatologic diseases, reproductive tract problems and tumors are among the most common conditions in hamsters and gerbils presented for veterinary care. This chapter addresses the most common presentations for the two species.
Nine cases of amyloidosis in caracals (Caracal caracal) from three different institutions in Europe were reviewed and evaluated histopathologically. The six males and three females died between 2008 and 2018 at an age of 6 yr ± 2.5 mo (median ± interquartile range). In two out of nine (2/9) animals, amyloidosis was an incidental postmortem finding; the animals died of bronchopneumonia and gastric ulceration due to Helicobacter spp., respectively. Seven (7/9) animals suffered from acute renal failure due to amyloidosis, one of them additionally of cardiac decompensation. The predominant clinical signs were weight loss, lethargy, dys- or anorexia, dehydration, increased BUN and creatinine, and azotemia. The main gross lesion was a pale renal cortex on cut surface; in two animals, the kidneys appeared enlarged. Histologically, glomerular amyloid was present in every animal (9/9), and was the predominant renal manifestation of amyloidosis. Additional findings included splenic amyloid (8/8), amyloid in the lamina propria of the intestine (5/5), and amyloid in the lingual submucosa (4/4). Gastric mineralization was present in four animals suffering from renal failure. In the animal dying from bronchopneumonia, severe pancreatic amyloid deposits mainly affecting the exocrine pancreas (1/5) were identified. Immunohistochemistry was employed to identify amyloid AA in eight cases; only in the caracal dying from bronchopneumonia AA was amyloid confirmed. In several organs, especially in those where only small amyloid deposits were detected, a Congo red stain was often necessary to confirm the deposition. The etiology of the amyloidosis remains unknown. Three caracals were related within two generations, another three within four generations, so one might hypothesize a familial trait. In conclusion, amyloidosis should be considered as a significant disease in the caracal. Particularly in cases with renal disease, it should be included as a major differential diagnosis.
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In this study, the effects of shelter density on feed intake, live weight gain and feed conversion ratio were investigated in lambs. A total of 40 male lambs at the age of 6 months were used (each group include 10 lambs). Animal number in the paddock constituted the basis of the experimental groups. These groups were as follow: 1 with one animal in the paddock, 2 with two animals in the paddock, 5 with five animals in the paddock and 10 group with ten animals in the paddock. 2.25 m2 areas provided each animal. The highest feed intake was found in 1 group (1251.96 g) followed by 2 group (1125.47 g), 5 group (1124.82 g) and 10 group (1105.56 g). Similarly, the highest daily live weight gain was found in 1 group (255.35 g) followed by 2 group (228.57 g), 5 group (212.49 g) and 10 group (194.67 g) (p<0.01). The best feed conversion ratio was found in 1 (4.90) and 2 (4.92) groups, followed by 5 (5.29) and 10 groups (5.68). In conclusion, this study showed that the increasing of animal density in paddock was affected negatively feed intake, live weight gain and feed conversion ratio.
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