4 Dec 2023, 11:22 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Empirical evidence suggests fishes meet the criteria for experiencing pain beyond a reasonable doubt and zebrafish are being increasingly used in studies of pain and nociception. Zebrafish are adopted across a wide range of experimental fields and their use is growing particularly in biomedical studies. Many laboratory procedures in zebrafish involve tissue damage and this may give rise to pain. Therefore, this FELASA Working Group reviewed the evidence for pain in zebrafish, the indicators used to assess pain and the impact of a range of drugs with pain-relieving properties. We report that there are several behavioural indicators that can be used to determine pain, including reduced activity, space use and distance travelled. Pain-relieving drugs prevent these responses, and we highlight the dose and administration route. To minimise or avoid pain, several refinements are suggested for common laboratory procedures. Finally, practical suggestions are made for the management and alleviation of pain in laboratory zebrafish, including recommendations for analgesia. Pain management is an important refinement in experimental animal use and so our report has the potential to improve zebrafish welfare during and after invasive procedures in laboratories across the globe.
23 Nov 2023, 7:01 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Non-alcoholic fatty liver disease (NAFLD) and subsequent steatohepatitis (NASH) is the most common cause of liver disease and liver transplantation in humans. Affecting millions of patients worldwide, diagnosis relies on a biopsy, not without risk to the patient, and emphasises the need for improved diagnostic measures to determine and monitor disease progression. Despite intensive research, approved pharmacological treatment modalities are few, underlining that animal models with increased translational validity are important to advance preclinical drug development. This study validates the applicability of computed tomography (CT) as a non-invasive diagnostic tool for the assessment of liver steatosis in a guinea pig model of NAFLD/NASH. Guinea pigs with induced NAFLD or NASH were compared to healthy controls at two separate time points: week 16, serving as baseline measure, and week 25 to monitor disease progression over time. The animals were subsequently euthanised, and samples were collected to confirm disease stage. The data showed a strong negative correlation between liver triglycerides and Hounsfield unit (HU) values (R2 = 0.8157; p < 0.0001). A significant difference in histopathological scoring and HU values between grade 0 and more advanced stages of steatosis was recorded (p < 0.001), although the degree of liver fibrosis could not be accurately evaluated by differences in HU. In conclusion, the present study validates CT scanning for the determination of hepatic steatosis in guinea pigs, and it strongly supports the technique as a relevant non-invasive diagnostic tool in this species.
3 Nov 2023, 5:59 am
Laboratory Animals
Laboratory Animals, Ahead of Print.
AbstractOn 1 January 2013, research using cephalopod molluscs, from hatchlings to adults, became regulated within Directive 2010/63/EU. There are significant difficulties in captive breeding in the great majority of currently utilised species. Thus, scientific research relies upon the use of wild-caught animals. Furthermore, live cephalopods are shared and transported between different stakeholders and laboratories across Europe and other continents. Despite existing European and national legislation, codes, guidelines and reports from independent organisations, a set of recommendations specifically addressing the requirements for the capture and transport of animals belonging to this taxon are missing. In addition, although training and development of competence for all people involved in the supply chain are essential and aim to ensure that animals do not suffer from pain, distress or lasting harm, the requirements for those capturing and transporting wild cephalopods have not been considered. This Working Group reviewed the current literature to recognise scientific evidence and the best practice, and compiled a set of recommendations to provide guidance on the ‘techniques’ to be used for the capture and transport of live cephalopods for their use in scientific procedures. In addition, we propose to (a) develop standardised approaches able to assess recommended methods and objectively quantify the impact of these processes on animals’ health, welfare and stress response, and (b) design a training programme for people attaining the necessary competence for capture and transportation of live cephalopods, as required by Directive 2010/63/EU.
28 Oct 2023, 3:12 am
Laboratory Animals
Laboratory Animals, Ahead of Print.
Poorly designed preclinical studies may compromise human health due to erroneous conclusions regarding treatment effects in addition to contributing to experimental irreproducibility and wasted resources. Randomization is one of the crucial steps to enhance scientific rigor and is a commonly recognized bias-reducing instrument that increases the reliability and reproduction of studies involving animals (even with syngeneic animals). This procedure should be considered when planning a study and reported during data publication. In this context, this work aimed to highlight the importance of adopting quality measures in preclinical trials, with an emphasis on animal randomization. The ‘Mouse Randomization’ app was developed to help researchers estimate an adequate sample size to obtain significant statistical power, ensuring the ethical use of animals. This app is freely available on the internet to carry out animal randomization and calculate sample sizes for in vivo experiments. We believe that this brief discussion about animal randomization could raise awareness among researchers on how to improve the quality of preclinical research, increasing reproducibility and avoiding animal misuse.
19 Sep 2023, 8:29 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
The reproducibility crisis across animal studies jeopardizes the credibility of the main findings derived from animal research, even though these findings are critical for informing human studies. To clarify and improve transparency among animal studies, the ARRIVE reporting guidelines were first announced in 2010 and upgraded to version 2.0 in 2020. However, compliance with and awareness of those reporting guidelines has remained suboptimal. Journal editors should encourage the authors to adhere to those guidelines. Authors, editors, referees, and reviewers should be aware of the ARRIVE guideline 2.0 when assessing and evaluating the methodology and findings of animal studies. However, we should also question whether reporting guidelines alone can change a research culture and improve the reproducibility of animal investigations. Reported research may not reflect actual research. Large segments of animal research efforts are wasted because of poor design choices and because of non-publication rather than suboptimal reporting. Better training of the scientific workforce, interventions at improving animal research at the design stage, registration practices, and alignment of the reward system with the publication of rigorous animal research may achieve more than reporting guidelines alone.
19 Sep 2023, 8:27 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Rats are a commonly used animal model for the study of the pathogenesis and novel treatments of glaucoma, which is induced experimentally using invasive, painful procedures. Peribulbar anaesthesia (PBA) is frequently used in people and domestic animals prior to ophthalmic surgeries to provide excellent perioperative analgesia. Our goal was to develop a PBA technique adapted to rat anatomy, improving the welfare of animals used as a model for glaucoma. Eighteen rat cadavers (n = 36 eyes) were used to establish the optimal needle insertion location. Five injection techniques using 0.1 mL/100 g lidocaine 2% and a contrast agent (1:1 volume ratio) were compared via computed tomography (CT). CT images were scored for injectate distribution at four locations: extraconal, intraconal, around the optic nerve and at the orbital fissure (scale 0–8, where 0 = none and 8 = excellent). Median scores using the dorso-medial-75° (5; range 2–6) and medial-canthus (4.5; range 2–8) injection techniques were not different from the dorso-medial-45° (4; range 3–6) technique and were higher (better distribution) compared with mid-ventral (3; range 2–5) and ventro-lateral (2; range 1–3) techniques. The two superior techniques were used in two experimental rats (n = 4 eyes) to determine the volume of bupivacaine 0.5% necessary to affect corneal touch threshold (CTT) and periocular skin sensitivity (PSS). A volume of 0.05 mL/100 g decreased CTT and PSS for several hours, while a larger volume produced excessively long effects. Dorso-medial-75° or medial-canthus PBA using 0.05 mL/100 g bupivacaine are likely to provide ocular and periocular analgesia in rats, with minor transient adverse effects.
19 Sep 2023, 8:20 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
The Yale Animal Resource Cost and Benchmarking survey©, conducted in US academic Animal Research/Resource Centers (ARC), was modified to capture similar thematic information in European Union (EU; including the non-EU countries Switzerland and the UK) academic ARCs, which are members of the League of European Research Universities (LERU). Participating institutions came from Denmark, England, Finland, France, Germany, Ireland, Italy, Netherlands, Scotland, Spain, and Switzerland. Survey data analysis suggests that: (a) in LERU programs, it is common to have more than one ARC under the umbrella of a single institution with organizational “lumping” of the financial, regulatory, and/or operational tasks under one administrative unit; (b) accreditation by an outside agency (e.g., the Association for the Assessment and Accreditation of Laboratory Animal Care) is more common in US than LERU ARCs; (c) LERU ARCs are responsible for murine breeding, which contrasts with US ARCs, where ∼40% of rodent breeding is managed by researchers; (d) cryopreservation is the most frequently requested fee-for-service offering among LERU participants (75% of participants) compared to 30% of US participants; (e) like US programs, almost all LERU programs have mice and rats, but fewer LERU programs have nonhuman primates (NHPs), and none have dogs on census; (f) LERU ARCs have about an equal amount of vivarium housing and procedure space, while US facilities have twice as much housing as procedure space; (g) a higher percentage of LERU colonies are free of Helicobacter and murine norovirus compared to US colonies; and (h) more LERU ARCs used environmental microbiologic monitoring of rodent colonies compared to US programs.
19 Sep 2023, 8:19 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
The Yale Animal Resource Cost and Benchmarking survey, conducted in United States (US) academic animal research/resource centres (ARC), was modified to capture similar information in European Union (EU) (including the non-EU countries Switzerland and the United Kingdom) academic ARCs, who are members of the League of European Research Universities (LERU). Participating institutions came from Denmark, England, Finland, France, Germany, Ireland, Italy, Netherlands, Scotland, Spain and Switzerland. Survey data analysis suggests that (a) per diem rates have similar compositions in LERU and US programs, with >50% of the rates dedicated to recovering salary and fringe, followed by supplies (∼25%), facility costs (∼10%) and other expenses (∼15%); (b)  ∼60% of US and LERU programs under-recover mouse care costs; (c) on average, LERU programs have a small positive net-operating balance, while US programs average a large deficit; (d) in LERU programs <50% of institutions fund the animal program deficit, while in US programs almost 100% of such deficits are covered by the institution; and (e) when setting per diem rates, both US and LERU programs rank cost accounting as the most influential factor. Both US and LERU programs are reluctant to raise per diem rates to the extent required to recover costs and, thus, continue to under-recover costs, resulting in the animal program being ‘caught in the middle’ between the competing financial challenges of investigator ‘affordability’ and the animal program’s fiduciary responsibility to the institution.
14 Sep 2023, 6:51 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Voluntary oral drug administration using sweet substances promotes rodents’ therapeutic compliance while reducing stress induced by forced drug administration. We aimed to test whether rats would willingly eat strawberry jam or condensed milk from a syringe, and which one they would prefer. Our results show that rats prefer condensed milk, demonstrating its potential as a vehicle for the voluntary oral administration of drugs in experimental protocols.
14 Sep 2023, 6:30 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Anesthetics are commonly used in fish for surgery and to facilitate capture, handling and transport in aquaculture and experimental procedures. In research, the selection of the anesthetic depends on its properties and on the recovery time. Eugenol has been pointed out as an effective anesthetic for fish, alternative to traditional drugs. Although Cnesterodon decemmaculatus is widely used as a model in ecological bioassays, no anesthetic protocol has been reported for this species. The aim of the present study was to evaluate the induction time (i.e. time to reach anesthetic stage VI) and recovery time in individuals of C. decemmaculatus subjected to eugenol at a fixed concentration, according to sex and pregnancy status. Forty-one fish were divided into three groups: males, pregnant females and non-pregnant females. They were measured for total length, standard length and weight, and the condition factor (K) was calculated. No significant differences in induction and recovery times were found for sex, pregnancy status and K between groups. Results are a contribution toward the development protocol of a standard anesthetic protocol for C. decemmaculatus.