Directive 2010/63/EU introduced requirements for the classification of the severity of procedures to be applied during the project authorisation process to use animals in scientific procedures and also to report actual severity experienced by each animal used in such procedures. These requirements offer opportunities during the design, conduct and reporting of procedures to consider the adverse effects of procedures and how these can be reduced to minimize the welfare consequences for the animals. Better recording and reporting of adverse effects should also help in highlighting priorities for refinement of future similar procedures and benchmarking good practice. Reporting of actual severity should help inform the public of the relative severity of different areas of scientific research and, over time, may show trends regarding refinement. Consistency of assignment of severity categories across Member States is a key requirement, particularly if re-use is considered, or the safeguard clause is to be invoked. The examples of severity classification given in Annex VIII are limited in number, and have little descriptive power to aid assignment. Additionally, the examples given often relate to the procedure and do not attempt to assess the outcome, such as adverse effects that may occur. The aim of this report is to deliver guidance on the assignment of severity, both prospectively and at the end of a procedure. A number of animal models, in current use, have been used to illustrate the severity assessment process from inception of the project, through monitoring during the course of the procedure to the final assessment of actual severity at the end of the procedure (Appendix 1).

Construction of different kinds of prostheses on irradiated bone tissues after tumour surgery is a complicated part of modern implantology. In irradiated regions of the jaws where the bone layers are thin and the blood supply also is minimal, knowledge of the impact of each dose of radiation is very important. The aim of this study was to compare the bone response around titanium implants loaded with fixed bridges in dog mandibles irradiated with total doses of 40, 50 or 60 Gy. The results suggest that after irradiation with 40-50 Gy, when the dose is fractioned in order to achieve higher tolerance of the tissues compared with single dose irradiation, titanium implants may become osseointegrated in the mandibles. For high success rates, however, careful planning of radiotherapy and selection of implantation site with an adequate blood supply are essential.

The isolated gray wolf (Canis lupus) population of the Scandinavian Peninsular is suffering from inbreeding depression. We studied dispersal of 35 wolves fitted with very high frequency (20) or Global Positioning System—global system for mobile (15) radiocollars in the neighboring Finnish wolf population. The growing wolf population in Finland has high numbers of dispersing individuals that could potentially disperse into the Scandinavian population. About half (53%) of the dispersing wolves moved total distances that could have reached the Scandinavian population if they had been straight‐line moves, but because of the irregular pattern of movements, we detected no wolves successfully dispersing to the Scandinavian population. Dispersal to the Scandinavian population was also limited by high mortality of wolves in reindeer (Rangifer tarandus) management areas and by dispersal to Bothnian Bay at times of the year when ice was not present. We suggest that when a small wolf population is separated from source populations by distance, barriers, and human exploitation, wildlife managers could promote the population's viability by limiting harvest in the peripheral areas or by introducing wolves from the source population.

Individual and permanent identification of experimental animals is a common and often essential research practice. There is little information available on the short-term effects of these procedures on the animals. In this study, seven rats were implanted with telemetric devices. The effects of three different identification methods (ear tattoo, ear notching and microtattoo) were compared. Cardiovascular data were collected for 24 h after the procedures. Time periods of 0-1, 1-4, 4-16 h (dark) and 16-24 h after the procedure were analysed separately. The most pronounced differences in measured parameters were observed during the first hour after the procedures were performed. Mean arterial pressure (MAP) was significantly higher (P < 0.012) following the ear tattoo than the microtattoo procedure by a difference of approximately 5 mmHg. Heart rate (HR) was significantly elevated (P < 0.001) after ear tattoo compared with both ear notching (Δ = 31 beats per minute [bpm]) and microtattoo (Δ = 44 bpm). During the 1-4 h period and the following dark period, the MAP was highest in the ear notching group, but no differences were observed in the HRs. During the following dark period (4-16 h) and the next day (16-24 h) differences in MAP and HR were minor. In conclusion, microtattoo appears to cause the mildest changes in HR and blood pressure. Based on these results, ear tattoo and ear notching should be replaced by microtattoo whenever possible.

Veterinary professionals working in partnership with other competent persons are essential for a successful animal care and use programme. A veterinarian's primary responsibilities are defined by their own professional regulatory bodies, but in this area of work there are further opportunities for contribution, which will assist in safeguarding the health and welfare of animals used in research. These guidelines are aimed not only at veterinarians to explain their duties, and outline the opportunities to improve the health and welfare of animals under their care, but also at employers and regulators to help them meet their responsibilities. They describe the desirability for postgraduate education towards specialization in laboratory animal medicine and detail the many competencies necessary to fulfil the role of the laboratory animal veterinarian. They detail the need for veterinary expertise to promote good health and good welfare of animals used in biomedical research during husbandry as well as when under experimental procedures. Regulatory and ethical aspects are covered as are the involvement of the veterinarian in education and training of others working in the animal care and use programme. Managerial aspects, including occupational health and safety, are also areas where the veterinarian's input can assist in the successful implementation of the programme.

Objectives: The structure of the mandibular condylar cartilage (MCC) is regulated by dynamic and multifactorial processes. The aim of this study was to examine the effects of altered dietary loading, estrogen level, and aging on the structure of the condylar cartilage and the expressions of matrix metalloproteinase (MMP) -3 and MMP-8 of rat MCC.Methods: In this study, Crl:CD (SD) female rats were randomly divided into 3 groups according to dietary hardness: hard diet (diet board), normal diet (pellet), and soft diet (powder). In each group, the rats were further divided into 2 subgroups by ovariectomy at the age of 7 weeks. The rats were sacrificed at 5-and 14-month-old.Histomorphometric analysis of the MCC thickness was performed after toluidine blue staining. Immunochemical staining was done for MMP-3 and MMP-8. A linear mixed model was used to assess the effects of dietary loading, estrogen level, and aging.Results: Increased dietary loading was the main factor to increase the MMP-3 expression and the anterior and central thickness of the MCC. Lack of estrogen was the main factor associated with decreased MMP-8. Aging was associated with the thickness changes of the whole condylar cartilage and the reduced expression of MMP-8. Conclusion:The condylar cartilage structure and metabolism of the female rats are 2 sensitive to dietary loading changes, estrogen level as well as aging. The proper balance of these factors seems to be essential for the maintenance of the condylar cartilage.

SummarySince sounds may induce physiological and behavioural changes in animals, it is necessary to assess and define the acoustic environment in laboratory animal facilities. Sound studies usually express sound levels as unweighted linear sound pressure levels. However, because a linear scale does not take account of hearing sensitivity-which may differ widely both between and within species at various frequencies-the results may be spurious. In this study a novel sound pressure level weighting for rats, R-weighting, was calculated according to a rat's hearing sensitivity. The sound level of a white noise signal was assessed using R-weighting, with H-weighting tailored for humans, A-weighting and linear sound pressure level combined with the response curves of two different loudspeakers. The sound signal resulted in different sound levels depending on the weighting and the type of loudspeaker. With a tweeter speaker reproducing sounds at high frequencies audible to a rat, R-and A-weightings gave similar results, but the H-weighted sound levels were lower. With a middle-range loudspeaker, unable to reproduce high frequencies, R-weighted sound showed the lowest sound levels. In conclusion, without a correct weighting system and proper equipment, the final sound level of an exposure stimulus can differ by several decibels from that intended. To achieve reliable and comparable results, standardization of sound experiments and assessment of the environment in animal facilities is a necessity. Hence, the use of appropriate species-specific sound pressure level weighting is essential. R-weighting for rats in sound studies is recommended.Keywords Auditory sensitivitYi hearing; physiologyi rati sound level; weightings All animals in animal facilities are exposed to environmental sounds. Various sounds have been shown to elicit physiological and behavioural changes in animals, which mean that the acoustic environment should also be controlled. The effects of sounds on hearing, different organs, growth, blood and the circulatory system have been reviewed by several groups (Pfaff 1974, Algers et a1. 1978, Peterson 1980, Gamble 1982. Moreover,

Condylar cartilage is sensitive to the interplay between loading, aging, and sex of middle-aged and older rats. High loading of condylar cartilage increased the thickness of cartilage in younger rats.