Laboratory Animals最新文献

A breeding pair of genetically engineered laboratory mice (Mus musculus) presented in apparent copulatory lock (coital tie). After anesthetizing the animals, gentle traction was used to separate the pair at which point a vaginal prolapse was detected and the penis was covered with black, firm, dry crusts and noted to have a solid pale, tan, firm cylindrical mass adhering to its glans. The vaginal prolapse was reduced and the female was returned to its cage. The male mouse had a severely distended bladder which could not be expressed and was euthanized. Histopathologic examination of the distal two-thirds of the penis revealed diffuse, acute coagulative necrosis. The mass adhered to the distal penis was a homogenous granular eosinophilic material consistent with a copulatory plug. While copulatory plugs and locks have been described in some rodent species, they have not been reported in laboratory mice. While the cause of the adherence of the plug to the penis could not be determined, we hypothesize that its adherence to both the penis and the vagina led to the lock and subsequently to ischemic necrosis of the distal penis.

Anesthesia with isoflurane prior to carbon dioxide euthanasia is recommended as a refinement, but vaporizer access can be limited. An alternative to vaporizers is the 'drop' method, introducing a fixed volume of isoflurane into the induction chamber. Previous work suggests that isoflurane administered at a concentration of 5% via the drop method is effective but aversive to mice; lower concentrations have not been tested. We assessed mouse behavior and insensibility with induction using the drop method for isoflurane concentrations below 5%. Male Crl:CD-1 (ICR) mice (n = 27) were randomly allocated to one of three isoflurane concentrations: 1.7%, 2.7%, and 3.7%. During induction, measures of insensibility and stress-related behaviors were recorded. All mice reached a surgical plane of anesthesia, and mice exposed to higher concentrations did so more quickly; as concentrations increased from 1.7 to 2.7 and 3.7%, the time to recumbency (Least squares means ± SE: 120.5 s ± 8.1, 97.9 s ± 8.1, and 82.8 s ± 8.1, respectively), loss of righting reflex (149.1 s ± 8.5, 127.7 s ± 8.5, and 100.7 s ± 8.5, respectively), and loss of pedal withdrawal reflex (214.5 s ± 8.3, 172.2 s ± 8.3, and 146.4 s ± 8.3, respectively) all declined. Rearing was the most frequently performed stress-related behavior, and was most pronounced immediately following isoflurane administration for all treatments. Our results indicate that the drop method can be used to effectively anesthetize mice with isoflurane concentrations as low as 1.7%; future work should assess mouse aversion.

The objective of this study was to investigate the feasibility of external jugular vein catheterization through an ear vein in piglets. Forty-six sevoflurane-midazolam anaesthetized piglets were included. External jugular vein catheterization was conducted through the ear vein using the Seldinger technique. Part 1 (n = 27): optimal puncture site was based on the deltoid tuberosity as a landmark to reach the external jugular vein. The final position of the catheter was verified in 25 piglets using computer tomography. Catheterization time was recorded and patency of the catheter assessed by repeated blood sampling for up to 4 h. Part 2 (n = 19): ear vein catheterization was without taking into account any landmarks. Functionality for blood sampling was evaluated as described in part 1. Catheter advancement was possible in 25/27 and 18/19 piglets in parts 1 and 2, respectively. Median (range) time required for successful catheterization was 1.95 (1-10) min (n = 38). The deltoid tuberosity was a good landmark to reach the external jugular vein. But blood sampling was also possible through catheters ending slightly cranial to the external jugular vein. Despite successful catheter advancement, blood sampling was not possible from one catheter in each part of the study (total: two piglets). One of these catheters presented luminal damage, while the other one presented as normal after being removed from the animal. Summarizing, central vein catheterization through the ear vein was feasible in 93.5% and repeated blood sampling was possible in 89.1% of the piglets (n = 46).

Auditory disabilities have a large impact on the human population worldwide. Research into understanding and treating hearing disabilities has increased significantly in recent years. One of the most relevant animal species in this context is the guinea pig, which has to be deafened to study several of the hearing pathologies and develop novel therapies. Applying kanamycin subcutaneously and furosemide intravenously is a long-established method in hearing research, leading to permanent hearing loss without surgical intervention at the ear. The intravenous application of furosemide requires invasive surgery in the cervical area of the animals to expose the jugular vein, since a relatively large volume (1 ml per 500 g body weight) must be injected over a period of about 2.5 min. We have established a gentler alternative by applying the furosemide by puncture of the leg veins. For this, custom-made cannula-needle devices were built to allow the vein puncture and subsequent slow injection of the furosemide. This approach was tested in 11 guinea pigs through the foreleg via the cephalic antebrachial vein and through the hind leg via the saphenous vein. Frequency-specific hearing thresholds were measured before and after the procedure to verify normal hearing and successful deafening, respectively. The novel approach of systemic deafening was successfully implemented in 10 out of 11 animals. The Vena saphena was best suited to the application. Since the animals' condition, post leg vein application, was better in comparison to animals deafened by exposure of the Vena jugularis, the postulated refinement that reduced animal stress was deemed successful.

Competent, confident and caring laboratory animal caretakers, technicians and technologists (LAS staff) are vital for good animal welfare, high-quality science and a secure Culture of Care. This requires high-quality education, training, supervision and continuing professional development (CPD) of LAS staff. However, there is a lack of harmonisation regarding how this education and training is conducted among European countries, and nor are there recommendations adapted to Directive 2010/63/EU. Therefore, FELASA and EFAT established a working group with the task of establishing recommendations for education, training and CPD for LAS staff. The working group established five different levels (LAS staff levels 0-4), defining the required level of competence and attitude, as well as suggesting educational requirements for reaching each level. Defining these levels should help to ensure that appropriate educational and CPD activities are in place, and to enable employers and LAS staff to determine the level and career stage attained. Furthermore, proper assessment of competencies and effective CPD schemes for all relevant staff should be established. Regulators should support this by setting standards for competence assessment and ensuring that they are consistently applied. In addition, establishments should involve the LAS staff in defining and developing the Culture of Care. The Animal Welfare Body should be involved and have oversight of education, training and CPD. These recommendations will contribute to harmonisation and increased quality of education, training and CPD, as well as provide clearer career pathways for LAS staff, helping to ensure high standards of animal welfare and science.

Directive 2010/63/EU of the European Parliament and the Council of 22 September 2010 states that at the end of a procedure, the most appropriate decision on the future of an animal previously used or intended for use in scientific procedures should be taken on the basis of animal welfare and potential risks to the environment. Member States may allow animals to be rehomed provided the health of the animal allows it, there is no danger to public health, animal health or the environment and if appropriate measures have been taken to safeguard the wellbeing of the animal. In countries where rehoming is permitted, it is the responsibility of the Animal Welfare Body to advise on a rehoming scheme which must include appropriate socialization in order to help facilitate successful rehoming, avoid unnecessary distress to the animals and guarantee public safety. This paper reviews the EU legislation, existing guidance, current literature and best practice to define rehoming, sets out general considerations for rehoming laboratory animals including socialization and provides practical advice on the steps required in a rehoming scheme. For those species most frequently rehomed, more detailed species-specific sections are included.

Application of dextran sodium sulfate (DSS) is often used to induce experimental colitis. Current state of the art is to refrain from the use of analgesics due to their possible interaction with the model. However, the use of analgesics would be beneficial to reduce the overall constraint imposed on the animals. Here, we analyzed the effect of the analgesics Dafalgan (paracetamol), Tramal (tramadol) and Novalgin (metamizole) on DSS-induced colitis. To study the effect of those analgesics in colitis mouse models, acute and chronic colitis was induced in female C57BL6 mice by DSS administration in the drinking water. Analgesics were added to the drinking water on days four to seven (acute colitis) or on days six to nine of each DSS cycle (chronic colitis). Tramadol and paracetamol had minor effects on colitis severity. Tramadol reduced water uptake and activity levels slightly, while mice receiving paracetamol presented with a better overall appearance. Metamizole, however, significantly reduced water uptake, resulting in pronounced weight loss. In conclusion, our experiments show that tramadol and paracetamol are viable options for the use in DSS-induced colitis models. However, paracetamol seems to be slightly more favorable since it promoted the overall wellbeing of the animals upon DSS administration without interfering with typical readouts of colitis severity.