25 Jun 2019, 9:47 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
The use of juvenile conventional pigs as a preclinical animal model to perform pharmacokinetic (PK), pharmacodynamic (PD) and safety studies for the paediatric population is increasing. Repetitive oral administration of drugs to juvenile pigs is however challenging. A representative method which can be used from birth till adulthood is necessary. The current study presents the placement and use of a gastrostomy button in pigs with a weight ranging from 2.4 to 161 kg. The surgical placement was performed via a laparotomic procedure on, each time, 12 pigs (six male, six female) of 1 week, 4 weeks, 8 weeks and 6–7 months old. For every age category, eight pigs were part of a PK study with a non-steroidal anti-inflammatory drug (NSAID) and four pigs served as a control group. No severe complications were observed during surgery. The button remained functional for 10 days in 40 out of 48 pigs. No significant differences in body temperature or white blood cell count were observed during the trial. Three control pigs showed signs of inflammation indicating a NSAID might be warranted. Autopsy revealed minimal signs of major inflammation in the abdominal cavity or the stomach. A limited number of pigs showed mucosal inflammation, ulcers or abscesses in the stomach or around the fistula. These results indicate that the laparotomic placement of a gastrostomy button might be considered safe and easy in growing pigs to perform repetitive oral dosing preclinical studies. However, the method is not advised in pigs weighing more than 100 kg.
25 Jun 2019, 6:24 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
A cohort of captive-bred red-eared slider turtles, Trachemys scripta, was received from a commercial vendor. Shortly after arrival, several turtles presented as lethargic with subjectively pale skin and multifocal areas of cotton-like tufts in the mouth area and distal extremities. The water was treated with a commercial anti-fungal and anti-bacterial preparation of Victoria Green B and acriflavine. Despite treatment, 10 turtles were euthanized and others demonstrated persistent clinical signs. A live turtle was submitted to a commercial diagnostic laboratory for microbiologic and histologic evaluation. Seven cultures were obtained from this turtle and numerous organisms grew from each culture, including Flavobacterium sp. Blood film analysis demonstrated intracytoplasmic gamonts of Haemogregarina sp. within erythrocytes. On necropsy, internal organs appeared to be slightly more adhered within the coelomic cavity than normal. The urinary bladder was markedly distended with turbid, dark yellow urine. Microscopic evaluation of the tissues revealed significant parasitism with Myxidium sp., Spirorchis sp. and Neopolystoma orbiculare. No fungal organisms were identified on histology or grown in culture. While there are scattered reports of these pathogens in freshwater turtles, none of the cases reported describe such extensive co-infections. It is likely that complicated infection and shipping stress exacerbated clinical signs typically seen with these organisms. Efforts to minimize stress and administration of prophylactic antiparasitic agents during the acclimation period may aid in reducing the consequences of internal parasitism in aquatic turtles.
19 Jun 2019, 9:39 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Plasma lipid and glucose levels are important parameters for evaluating the onset and development of metabolic and cardiovascular diseases. In clinical and experimental studies of humans or mice, fasting is often required before testing plasma lipid and glucose levels. The rabbit is a valuable animal model for cardiovascular disease research. However, whether fasting is necessary for measuring plasma lipid and glucose levels in rabbits remains unclear. In the current study, 12 healthy Japanese white rabbits (males weighing 2.5–3.0 kg) were randomly divided into a chow diet group (n = 6) and a high cholesterol diet group (n = 6). They were fed either a standard chow diet or a chow diet supplemented with 0.5% cholesterol and 3% corn oil for 12 weeks. After 12 weeks, the plasma levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and glucose were measured before and after various fasting durations (8, 12, 16, 20 and 24 h). The results showed that there were no significant differences in lipid levels between the fasting and non-fasting samples, whereas glucose levels were lower after 8 h of fasting than in the absence of fasting. Moreover, the glucose levels were restored to normal after 8 h of refeeding. These results indicate that fasting does not affect plasma lipid values in rabbits but that fasting is important for determining the glucose level in rabbits. These findings may be helpful for future rabbit experiments and beneficial for animal welfare.
13 Jun 2019, 10:44 pm
Laboratory Animals
Laboratory Animals, Ahead of Print.
Hygienic monitoring of laboratory rodents has focused more and more on the analysis of environmental sample material by quantitative polymerase chain reaction (qPCR) assays. This approach requires profound knowledge of specific genetic sequences of the agents to be monitored and the assays need to be permanently adapted to take the latest research into account. [Pasteurella] pneumotropica was recently reclassified into the new genus Rodentibacter, with Rodentibacter (R.) pneumotropicus and R. heylii as the most commonly detected species in laboratory mouse colonies. This study aimed at the development of a specific qPCR assay for the simultaneous detection of both agents.A novel primer probe set, based on detection of the specific virulence factor‚ ‘inclusion body protein A’ gene (ibpA), was confirmed by testing the assay on currently described Rodentibacter type species and other Pasteurellaceae. Furthermore, it was validated within four different barrier units and results were compared with the cultural analysis of sentinel mice.The assay was suitable to specifically detect R. pneumotropicus and R. heylii and discriminate them from other murine Rodentibacter spp. In addition, it revealed high sensitivity for the detection of both agents in environmental sampling material including exhaust air dust in individually ventilated cage systems. Altogether, higher pathogen prevalence was detected via qPCR of environmental samples compared with cultural diagnostics of sentinel mice.This study describes a qPCR assay for the simultaneous detection of R. pneumotropicus and R. heylii. This assay was demonstrated to be beneficial during routine health monitoring, especially with regard to environmental sampling strategies.
2 Jun 2019, 11:00 pm
Laboratory Animals
Laboratory Animals, Volume 53, Issue 1_suppl, Page 28-203, June 2019.
2 Jun 2019, 11:00 pm
Laboratory Animals
Laboratory Animals, Volume 53, Issue 1_suppl, Page 7-25, June 2019.
2 Jun 2019, 11:00 pm
Laboratory Animals
Laboratory Animals, Volume 53, Issue 1_suppl, Page 3-3, June 2019.
2 Jun 2019, 11:00 pm
Laboratory Animals
Laboratory Animals, Volume 53, Issue 1_suppl, Page 2-2, June 2019.
30 May 2019, 12:26 am
Laboratory Animals
Laboratory Animals, Ahead of Print.
In this study, the effect of four anaesthetic protocols that included the combination of xylazine (X) and ketamine (K) with acepromazine (A) and opioids (methadone (Me), morphine (Mo) or tramadol (T)) was evaluated in laboratory rats of both sexes. Ultrasonic vocalization (USV) was used as an indicator of pain during the recovery period. The objective was to evaluate the physiological parameters and the analgesic effect of each protocol to determine which protocol was the safest and fulfil the requirements of a balanced anaesthesia. The better protocols were the XKA protocol for both sexes and the XKMe protocol for females because the combinations achieve surgical plane of anaesthesia in rats. However, pain assessment during the formalin test revealed that rats anaesthetized with XKA produced more numbers of USV, suggesting that it is not a good protocol for the control of immediate postoperative pain. All protocols produced depression in body temperature and respiratory and heart rates, and had important effects, such as micturition and maintenance of open eyes. Only rats anaesthetized with XKA protocol did not present piloerection. These results demonstrated that good monitoring and care during anaesthesia must be included to prevent complications that compromise the life of the animal and to ensure a good recovery. The inclusion of analgesia in anaesthesia protocols must be used routinely, ensuring minimal presence of pain and thus more reliable results in the experimental procedures.
17 May 2019, 1:10 am
Laboratory Animals
Laboratory Animals, Volume 53, Issue 3, Page 259-270, June 2019.
In recent years, tremendous advances have been made in our ability to characterize complex microbial communities such as the gut microbiota, and numerous surveys of the human gut microbiota have identified countless associations between different compositional attributes of the gut microbiota and adverse health conditions. However, most of these findings in humans are purely correlative and animal models are required for prospective evaluation of such changes as causative factors in disease initiation or progression. As in most fields of biomedical research, microbiota-focused studies are predominantly performed in mouse or rat models. Depending on the field of research and experimental question or objective, non-rodent models may be preferable due to better translatability or an inability to use rodents for various reasons. The following review describes the utility and limitations of several non-rodent model species for research on the microbiota and its influence on host physiology and disease. In an effort to balance the breadth of potential model species with the amount of detail provided, four model species are discussed: zebrafish, dogs, pigs, and rabbits.