Rickard M.,Sequani Ltd. |
Rickard M.,Animal Health and Veterinary Laboratories Agency AHVLA
Animal Technology and Welfare | Year: 2011
When it is not feasible to accommodate and maintain a parent flock and hatchery for varying reasons that might include avoiding production of surplus stock, it is necessary to purchase day old turkeys from selected commercial suppliers and rear them to age. The successful rearing of the required number of turkeys which are 'fit for purpose' to enter a study is challenging. Batches of turkeys may suffer from 'failure to survive syndrome' or 'starve out' 1 during which they fail to eat and subsequently die, excessive feather and vent pecking will lead to further mortalities. The aim of this investigation was to study whether the provision of enrichment items reduced the occurrence of feather pecking therefore reducing mortality within batches of turkeys aged between one day old to 4 weeks of age. This knowledge would be used to implement a reduction in the number of day old turkeys being purchased in order to supplement expected heavy losses and ensure the active program of animal welfare continues to remain at a high standard. Source
Downes N.,Sequani Ltd.
Toxicologic Pathology | Year: 2012
The recent increase in numbers of juvenile toxicity studies over the past few years has doubtless added to our knowledge of the development of organ systems in the young rodent, but it is perhaps rather more difficult to answer the questions as to whether this body of work has served us well in terms of assessing risk in the pediatric population. If there are shortcomings, are they the result of poor study design or poor sensitivity of the model, or are the wrong questions being posed? This article provides a superficial overview of the progress made thus far and considers which aspects of study design and model choice currently fail to adequately address the major issues surrounding pediatric toxicology. © 2012 by The Author(s). Source
Weaver M.L.,Novartis |
Schutzsack J.,LEO Pharma A S |
Parish J.,Covance |
Logsted J.,CiToxLAB |
And 13 more authors.
Toxicologic Pathology | Year: 2016
Minipigs have been used for dermal drug development studies for decades, and they are currently more frequently considered as the second nonrodent species for pivotal nonclinical studies, in lieu of the dog or nonhuman primate, for compounds delivered via standard systemic routes of administration. Little is known about the tolerability of different excipients in minipigs; sharing knowledge of excipient tolerability and compositions previously used in nonclinical studies may avoid testing of inadequate formulations, thereby contributing to reduced animal usage. This article reviews vehicles employed in the Göttingen® minipig based on the combined experience from a number of pharmaceutical companies and contract research organizations. The review includes vehicles tolerated for single or multiple dosing by the Göttingen minipig, some of which are not appropriate for administration to other common nonrodent species (e.g., dogs). By presenting these data for dermal, oral, subcutaneous, and intravenous routes of administration, studies to qualify these vehicles in minipigs can be minimized or avoided. Additionally, investigators may more frequently consider using the minipig in place of higher species if the tolerability of a vehicle in the minipig is known. © Society of Toxicologic Pathology. Source
Downes N.,Sequani Ltd.
Toxicologic Pathology | Year: 2010
The rodent bioassay has been a mainstay of carcinogenic risk assessment for close to half a century; not that it has been without criticism in that time. As early as the 1990s, there were clearly established shortcomings with regard to relevance and extrapolation, but despite these concerns, this test continues relatively unchanged. As our understanding of the mechanisms of carcinogenesis and the availability of investigative techniques improve, there seems less reason than ever to persist with this exercise that provides little meaningful scientific data at great cost in terms of animal usage and pathologist time. This article highlights possible ways to gather and present data pertinent to carcinogenesis in man and suggests that it is the toxicological pathology community that should take the lead here in persuading regulators that there is great room for improvement in this particular aspect of regulatory pathology. Copyright © 2010 by The Author(s). Source
Downes N.,Sequani Ltd.
Toxicologic Pathology | Year: 2015
Throughout the last 50 years, the paradigm for carcinogenicity assessment has depended on lifetime bioassays in rodents. Since 1997, the International Conference on Harmonisation (ICH) S1B has permitted the use of a 2-year rodent bioassay (usually in the rat) and an alternative, genetically modified mouse model to support cancer risk assessment of pharmaceuticals. Since its introduction, it has become apparent that many of the stated advantages of the 6-month Tg mouse bioassay have, in actual fact, not been realized, and the concern exists that an albeit imperfect, 2-year mouse bioassay has been replaced by a similarly imperfect 6-month equivalent. This essay argues strongly that model systems, using cancer as the end point, should be discontinued, and that the recent initiatives, from the Organization for Economic Cooperation and Development and Institute of Peace and Conflict Studies, on 'mode of action,' 'adverse outcome pathways,' and 'human relevance framework' should be embraced as being risk assessments based upon the available science. The recent suggested revisions to the ICH S1 guidelines, utilizing carcinogenicity assessment documents, go some way to developing a science-based risk assessment that does not depend almost entirely on a single, imperfect, cancer-based end point in nonrelevant animal species. © 2015 by The Author(s). Source