A comparative molecular study of the presence of "Candidatus arthromitus" in the digestive system of rainbow trout, Oncorhynchus mykiss (Walbaum), healthy and affected with rainbow trout gastroenteritis
Del-Pozo J.,Easter Bush Veterinary Center |
Del-Pozo J.,University of Stirling |
Turnbull J.,University of Stirling |
Ferguson H.,University of Stirling |
Crumlish M.,University of Stirling
Journal of Fish Diseases | Year: 2010
Observations were made using histopathological techniques in conjunction with a nested polymerase chain reaction (PCR) protocol for the specific detection of " Candidatus arthromitus" on DNA extracted from wax-embedded tissues and fresh digestive contents of rainbow trout. Samples positive for " Candidatus arthromitus" DNA included fish with rainbow trout gastroenteritis (RTGE), clinically normal cohabiting fish, and apparently healthy controls from RTGE positive and RTGE negative sites. The results obtained from the PCR were confirmed by nucleotide sequencing. " Candidatus arthromitus" DNA was found in distal intestine as well as in sections of pyloric caeca, suggesting that both these locations are appropriate for molecular detection of " Candidatus arthromitus" DNA in trout. Furthermore, rainbow trout fry distal intestinal samples from two different hatcheries where RTGE had not been reported were also positive. Differences in " Candidatus arthromitus" DNA detection between paraffin wax-embedded and fresh digestive content samples from the same fish suggested that it may be predominantly epithelium-associated in healthy trout. Parallel histopathological observations indicated that pyloric caeca are the preferred site for visualizing segmented filamentous bacteria (SFB) in trout with RTGE. The results of this study showed that the presence of SFB was not invariably associated with clinical disease and that more information is required to understand the role of these organisms. © 2009 Blackwell Publishing Ltd.
Paoli M.A.,Easter Bush Veterinary Center |
Lahrmann H.P.,Pig Research Center |
Jensen T.,Pig Research Center |
D'Eath R.B.,Animal and Veterinary science Research Group
Animal Welfare | Year: 2016
Tail-biting in pigs (Sus scrofa) reduces welfare and production. Tail-docking reduces (but does not eliminate) tail-biting damage. The reason tail-docking reduces tail damage is unknown. It may reduce pigs' attraction to tails (HI), or increase tails' sensitivity to investigation (H2). To investigate these hypotheses, behavioural differences between 472 individually marked grower pigs with intact tails (nine groups of 25-34 pigs) or docked tails (nine groups of 22-24 pigs) were observed from 5-8 weeks of age on a commercial farm in Denmark. Pens had part-slatted floors, dry feeding and two handfuls of straw per day, and enrichment objects were provided. Behavioural sampling recorded actor and recipient for tail-directed (tail interest, tail in mouth, tail reaction) and investigatory behaviours (belly-nosing, ear-chewing, interaction with enrichment). Scan sampling recorded pig posture/activity and tail posture. Intact-tail pigs performed more overall investigatory behaviours but tail type did not affect the amount of tail-directed behaviours. Larger pigs performed more investigatory and tail-directed behaviours than smaller pigs and females performed slightly more tail investigation. Tail-directed behaviours were not consistent over time at the individual or group level. However, ear-chewing was consistent at the group level. One group with intact tails was affected by a tail-biting outbreak in the final week of the study (evidenced by tail-damage scores) and showed an increase over time in tail posture (tail down) and tail-directed behaviour but not activity. Overall, there were few behavioural differences between docked and undocked pigs: no evidence of reduced tail investigation (HI) or an increased reaction to tail investigation (H2) in docked pigs, and yet docked pigs had less tail damage. We propose that docking might be effective because longer tails are more easily damaged as pigs are able to bite them with their cheek teeth. © 2016 Universities Federation for Animal Welfare.
Abbondati E.,University of Cambridge |
Del-Pozo J.,Easter Bush Veterinary Center |
Hoather T.M.,University of Cambridge |
Constantino-Casas F.,University of Cambridge |
Dobson J.M.,University of Cambridge
Veterinary Pathology | Year: 2013
Tumor hypoxia has been associated with increased malignancy, likelihood of metastasis, and increased resistance to radiotherapy and chemotherapy in human medicine. Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor that is induced by tumor hypoxia and regulates the pathways involved in cellular response and adaptation to the hostile tumor microenvironment. HIF-1 induces transcription of different proteins, including Ca-IX and Glut-1, which are considered endogenous markers of chronic hypoxia in solid tumors in humans. In this study, sections from 40 canine sarcomas (20 histiocytic sarcomas and 20 low-grade soft-tissue sarcomas) were immunostained for these markers. Expression of Glut-1 was scored based on percentage of positive staining cells (0 = <1%; 1 = 1%-50%; 2 = >50%) and intensity of cellular staining (1 = weak; 2 = strong); Ca-IX was scored based on percentage of positive cells (0 = <1%; 1 = 1%-30%; 2 = >30%). Intratumoral microvessel density was measured using CD31 to assess intratumoral neoangiogenesis. Histiocytic sarcomas showed statistically significant higher Glut-1 immunoreactivity and angiogenesis than did low-grade soft-tissue sarcomas. Intratumoral microvessel density in histiocytic sarcomas was positively associated with Glut-1 immunoreactivity score. These findings suggest a potential role of hypoxia in the biology of these tumors and may provide a base for investigation of the potential prognostic use of these markers in naturally occurring canine tumors. © The Author(s) 2013.
Sargison N.D.,Easter Bush Veterinary Center |
Jackson F.,Moredun Research Institute |
Gilleard J.S.,University of Calgary
Veterinary Journal | Year: 2011
The effects of host age and immune suppression on abomasal parasitic infection in sheep were investigated following single experimental oral infections with MHco3 (ISE), MHco4 (WRS) and MHco10 (CAVR) strains of Haemonchus contortus in naïve 5-month-old crossbred lambs (n= 1 per group) and 15-month-old Greyface sheep treated with methyl prednisolone acetate (n= 2 per group) or without corticosteroid treatment (n= 2 per group). Adult female H. contortus in 5-month-old lambs (n= 1 per group) shed on average 6.5, 3.1 and 8.0 times more eggs than in 15-month-old sheep (n= 4 per group) following infection with MHco3 (ISE), MHco4 (WRS) and MHco10 (CAVR) strains of H. contortus, respectively, over a period of 28. days following the commencement of patency. There was no obvious effect of age of sheep or corticosteroid treatment on the abomasal establishment of H. contortus or on in vitro assays for egg hatching or larval feeding at different concentrations of anthelmintics, although statistical analysis could not be performed due to the small group sizes. © 2010 Elsevier Ltd.
Claxton A.M.,Easter Bush Veterinary Center
Applied Animal Behaviour Science | Year: 2011
Environmental enrichment strategies are used to improve both the physiological and psychological welfare of captive animals, which can be achieved by increasing the expression of natural behaviour and decreasing abnormal behaviours. Examples of successful environmental enrichment include the improvement of enclosure design, and the provision of feeding devices, novel objects, appropriate social groupings and other sensory stimuli. However, a key factor contributing to how a captive animal interacts with its environment is its relationship with humans. Firstly, this paper focuses upon the extent to which an animal's fear of humans may affect its overall behaviour, and the consequences of the subsequent human-animal relationship (HAR).Widely studied in farmed animals, the majority of data collected in the area of the HAR in exotic species largely focuses on primates and it is therefore also considered that further investigation is required to understand the impact of the HAR, particularly on the behaviour and welfare of a broader range of zoo-housed species - whose routine involves daily contact with both familiar and unfamiliar people. Research concerning the HAR is put into context of the field of environmental enrichment by discussing evidence which suggests that human contact meets some of the criteria that traditional methods of environmental enrichment aim to satisfy. A model has been developed to test the HAR in the zoo environment and, in doing so, predictions can be reliably made about how animals may react to humans. Here, the model has been further adapted to include predictions about the extent to which the HAR may affect an animal's daily behaviour budget and its reactions to other aspects of the zoo environment. It is also suggested that comparisons can be made directly between an animal's response to humans and to traditional enrichment methods in an attempt to determine if the HAR itself has any use as a form of environmental enrichment. Future research in this field has important implications for the management of captive zoo-housed animals through the design of appropriate husbandry procedures to improve captive animal behaviour on a species-specific basis and, in turn, for satisfying the zoo mission as a whole. © 2011 Elsevier B.V.