African spiny mice (Acomys spp.) are unique precocial rodents that are found in Africa, the Middle East, and southern Asia. They exhibit several interesting life-history characteristics, including precocial development, communal breeding, and a suite of physiologic adaptations to desert life. In addition to these characteristics, African spiny mice are emerging as an important animal model for tissue regeneration research. Furthermore, their important phylogenetic position among murid rodents makes them an interesting model for evolution and development studies. Here we outline the necessary components for maintaining a successful captive breeding colony, including laboratory housing, husbandry, and health monitoring aspects. We also review past and present studies focused on spiny mouse behavior, reproduction, and disease. Last, we briefly summarize various current biomedical research directions using captive-bred spiny mice.

Measurement of the blood lactate concentration is a useful monitoring tool during anesthesia of animals and people. Recently, blood lactate has been used to monitor anesthetized pigs, but very little is known about variations in blood lactate concentrations in this species. We therefore evaluate the effects of breed (domestic pigs compared with Göttingen minipigs), body weight (domestic pigs of 40 kg compared with 70 kg), type of anesthesia (inhalation compared with infusion) and surgery (minor compared with major surgery) on blood lactate concentrations in pigs. Anesthesia reports from 81 pigs are included. We find significantly higher blood lactate levels in minipigs anesthetized with isofluorane (2.53 ± 1.10 mmol/L) compared with domestic pigs (0.68 ± 0.48 mmol/L). Body weight, type of anesthesia, and type of surgery had no effect on blood lactate levels. Therefore, reference values for blood lactate concentrations in pigs should reflect the breed of interest.

The cage floor space recommended for a female rat with a litter is greater in the 8th edition of the Guide for the Care and Use of Laboratory Animals than in previous editions. As a result, research institutions using commonly available cages to house rats may not offer the recommended amount of space for a breeding pair and litter housed in the same cage. We evaluated breeding parameters in rats housed in cages with 143 in² (922.6 cm²) compared with 210 in² (1355 cm²) of floor space. Given the strains of rats typically used at our institution, a monogamous breeding pair and litter requires 164 in² (1058.1 cm²) of floor space according to the Guide. Pairs of breeding animals were housed in each type of cage; and average time between litters, number of litters born, percentage of litter weaned, numbers of pups born and weaned, and average weaning weights were evaluated. None of the breeding parameters evaluated differed according to the floor space of the cage in which the rats were housed.

This study sought to identify an optimal rodent bedding and cage-change interval to establish standard procedures for the IVC in our rodent vivarium. Disposable cages were prefilled with either corncob or α-cellulose bedding and were used to house 2 adult Sprague–Dawley rats (experimental condition) or contained no animals (control). Rats were observed and intracage ammonia levels measured daily for 21 d. Intracage ammonia accumulation became significant by day 8 in experimental cages containing α-cellulose bedding, whereas experimental cages containing corncob bedding did not reach detectable levels of ammonia until day 14. In all 3 experimental cages containing α-cellulose, ammonia exceeded 100 ppm (our maximum acceptable limit) by day 11. Two experimental corncob cages required changing at days 16 and 17, whereas the remaining cage containing corncob bedding lasted the entire 21 d without reaching the 100-ppm ammonia threshold. These data suggests that corncob bedding provides nearly twice the service life of α-cellulose bedding in the IVC system.

Although guinea pigs (Cavia porcellus) have been used in research for more than a century and remain the most prevalent USDA-covered species, little has been elucidated regarding the recognition of clinical pain or analgesic efficacy in this species. We sought to assess pain in guinea pigs by using newer, clinically relevant methods that have been validated in other rodent species: the behavioral ethogram and cageside proxy indicator. In this study, 10 male guinea pigs underwent electronic von Frey testing of nociception, remote videorecording of behavior, and cageside assessment by using time-to-consumption (TTC) of a preferred treat test. These assessments were performed across 2 conditions (anesthesia only and castration surgery under anesthesia) at 3 time points (2, 8, and 24 h after the event). The anesthesia only condition served to control for the nonpainful but potentially distressing components of the surgical experience. Compared with those after anesthesia only conditions, subtle body movements were increased and nociceptive thresholds were decreased at 2 and 8 h after surgery. At 24 h, neither subtle body movement behaviors nor nociceptive thresholds differed between the 2 conditions. In contrast, TTC scores did not differ between the anesthesia only and surgery conditions at any time point, underscoring the challenge of identifying pain in this species through cageside evaluation. By comparing ethogram scores with measures of nociception, we validated select behaviors as pain-specific. Therefore, our novel ethogram allowed us to assess postoperative pain and may further serve as a platform for future analgesia efficacy studies in guinea pigs.

The traditionally cited recommendations for the preoperative restriction of food (including bedding) and water in pigs do not appear to be evidence-based. As a preliminary step in elucidating a rationale for and standardizing preoperative food and water restriction (PFWR), this structured review recorded recent reported practices in PFWR in laboratory pigs and its consequences. Medline, Google Scholar and Web of Science databases were searched for recently published (2012 – 2014) recovery surgery procedures in pigs. Information pertaining to PFWR practices, as delineated in the ARRIVE guidelines, was extracted from the 233 articles retrieved. Food withdrawal was described in 73 of the 233 (31%) papers evaluated, bedding withdrawal in 5 articles (2%), and water withholding in 13 publications (6%) papers. Food, bedding, and water withdrawal regimens had a median (range) duration of 12 (4 to 48), 48 (48 to 72), and 12 (2 to 12) h, respectively. Compared with other types of procedures, articles describing gastrointestinal or abdominal surgery were more likely to report fasting regimes. Liquid diets were described in 11 of the 233 (5%) publications evaluated. Adverse effects of PFWR effects were not reported. These data reveal considerable variation in PFWR practices. The stress of fasting coupled with the absence of evidence for current recommendations makes the rationale and standards for PFWR in pigs worthy of further study.

Training techniques that prepare laboratory animals to participate in testing via cooperation are useful tools that have the potential to benefit animal wellbeing. Understanding how animals systematically vary in their cooperative training trajectories will help trainers to design effective and efficient training programs. In the present report we document an updated method for training rhesus monkeys to cooperatively participate in restraint in a 'primate chair.' We trained 14 adult male macaques to raise their head above a yoke and accept yoke closure in an average of 6.36 training days in sessions that lasted an average of 10.52 min. Behavioral observations at 2 time points prior to training (approximately 3 y and 1.3 y prior) were used to quantify behavioral reactivity directed toward humans and toward other macaques. Individual differences in submissive–affiliative reactivity to humans but not reactivity toward other monkeys were related to learning outcomes. Macaques that were more reactive to humans were less willing to participate in training, were less attentive to the trainer, were more reactive during training sessions, and required longer training sessions, longer time to yoke, and more instances of negative reinforcement. These results suggest that rhesus macaques can be trained to cooperate with restraint rapidly and that individual difference data can be used to structure training programs to accommodate variation in animal temperament.

The Public Health Service Policy on the Humane Care and Use of Laboratory Animals and sound ethical practices require institutions to provide safe working environments for personnel working with animals; this mandate is achieved in part by establishing an effective animal care Occupational Health and Safety Program (OHSP). Land-grant institutions often face unique organizational challenges in fulfilling this requirement. For example, responsibilities for providing health and safety programs often have historically been dispersed among many different divisions scattered around the campus. Here we describe how our institutional management personnel overcame organizational structure and cultural obstacles during the formation of a comprehensive campus-wide animal care OHSP. Steps toward establishing the animal care OHSP included assigning overall responsibility, identifying all stakeholders, creating a leadership group, and hiring a fulltime Animal Care OHSP Specialist. A web-based portal was developed, implemented, and refined over the past 7 y and reflected the unique organizational structures of the university and the needs of our research community. Through this web-based portal, hazards are identified, risks are assessed, and training is provided. The animal care OHSP now provides easy mandatory enrollment, supports timely feedback regarding hazards, and affords enrollees the opportunity to participate in voluntary medical surveillance. The future direction and development of the animal care OHSP will be based on the research trends of campus, identification of emerging health and safety hazards, and ongoing evaluation and refinement of the program.

Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks' air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.

Mice purportedly require dosing with the opioid buprenorphine (Bup-HCl) at least every 8 to 12 h to maintain an adequate plane of analgesia. Here we used an experimental laparotomy model to determine the clinical efficacy of sustained-release formulations of buprenorphine (Bup-SR) after surgery in mice. Female CD1 mice underwent laparotomy and received either Bup-SR (0.6 mg/kg), Bup-HCl (0.1 mg/kg every 12 h), or saline (every 12 h). Pain was assessed at 1, 3, 6, 12, 24, 48, and 72 h according to the frequency of several behaviors (general activity, wheel-running activity, rearing, grooming, wound licking, orbital tightening, and percentage of integrated nest material) and daily body weight. Over time, wheel running was increased and wound licking was decreased in Bup-SR–treated mice compared with Bup-HCl– and saline-treated mice. Compared with Bup-HCl– and saline-treated mice, Bup-SR–treated mice had increased general activity and percentage of integrated nest material and decreased orbital tightening for 1 to 6 h after surgery. The Bup-HCl– and saline-treated mice had similar general activity, orbital tightening scores, and wheel running activity. Rearing activity and body weight did not differ throughout the study, and none of the observed behaviors differed between groups at 24, 48, and 72 h after surgery. These results suggest that Bup-SR at 0.6 mg/kg provides adequate analgesia after laparotomy in mice and can be used as an alternative analgesic in this context. Furthermore, Bup-HCl at 0.1 mg/kg every 12 h may be inadequate in providing analgesia for abdominal procedures in mice.

Effective pain management for rats and mice is crucial due to the continuing increase in the use of these species in biomedical research. Here we used a recently validated operant orofacial pain assay to determine dose–response curves for buprenorphine and tramadol when mixed in nut paste and administered to male and female rats. Statistically significant analgesic doses of tramadol in nut paste included doses of 20, 30, and 40 mg/kg for female rats but only 40 mg/kg for male rats. For male rats receiving buprenorphine mixed in nut paste, a significant analgesic response was observed at 0.5 and 0.6 mg/kg. None of the doses tested produced a significant analgesic response in female rats. Our results indicate that at the doses tested, tramadol and buprenorphine produced an analgesic response in male rats. In female rats, tramadol shows a higher analgesic effect than buprenorphine. The analgesic effects observed 60 min after administration of the statistically significant oral doses of both drugs were similar to the analgesic effects of 0.03 mg/kg subcutaneous buprenorphine 30 min after administration. The method of voluntary ingestion could be effective, is easy to use, and would minimize stress to the rats during the immediate postoperative period.

Information regarding effective anesthetic regimens for neonatal rat pups is limited. Here we investigated whether isoflurane or sevoflurane anesthesia maintains physiologic parameters more consistently than does hypothermia anesthesia in neonatal rat pups. Rat pups (age, 4 d) were randomly assigned to receive isoflurane, sevoflurane, or hypothermia. Physiologic parameters monitored at 1, 5, 10, and 15 min included heart rate (HR), respiratory rate (RR), and oxygen saturation (%SpO₂). Other parameters evaluated were loss and return of righting reflex, paw withdrawal reflex, and maternal acceptance. Corticosterone and glucose were sampled at 20 min and 24 h after anesthesia induction. Once a surgical plane of anesthesia was achieved, a skin incision was made on the right lateral thigh. After the procedure, all pups were accepted and cared for by their dam. Isoflurane- and sevoflurane-treated pups maintained higher HR, RR, %SpO₂, and glucose levels than did hypothermia-treated pups. For both the isoflurane and sevoflurane groups, HR and RR were significantly lower at 10 and 15 min after anesthesia than at 1 min. Compared with hypothermia, isoflurane and sevoflurane anesthesia provided shorter times to loss of and return of the righting reflex. Although corticosterone did not differ among the groups, glucose levels were higher at 20 min after anesthesia induction than at 24 h in all anesthetic groups. We conclude that both isoflurane and sevoflurane anesthesia maintain physiologic parameters (HR, RR, %SpO₂) more consistently than does hypothermia anesthesia in 4-d-old rat pups.

Urethane anesthesia preserves many reflex functions and is often the preferred anesthetic for urodynamic studies in rats. Because of the toxicity profile of urethane, its use as an anesthetic typically is limited to acute and terminal investigations. Alternative anesthetic options are needed for longitudinal studies of micturition reflexes in rats. In this study, we evaluated propofol anesthesia administered at constant rate infusion at different planes of anesthesia in rats for combined cystometrography and external urethral sphincter (EUS) EMG in rats. No reflex micturition was noted after rats received 100%, 80%, or 60% of a previously reported anesthetic dose of propofol. At 40% of the standard propofol dose, a subset of rats showed reflex voiding, with bladder contractions and associated EUS EMG activity. In contrast, urethane anesthesia at a surgical plane allowed for reflex voiding with bladder contractions and EUS activation. Latency to leaking or voiding was longer in rats under propofol anesthesia than in those under urethane anesthesia. In a subset of rats with reflex voiding under propofol anesthesia, voiding efficiency was decreased compared with that of rats anesthetized with urethane. We conclude that propofol anesthesia suppresses micturition reflexes in rats more efficiently than did urethane. Propofol is a suitable anesthetic for longitudinal studies in rats, but its use for urodynamic evaluations is limited in these animals due to its marked suppression of both bladder contractions and EUS EMG activation.

The objective of this study was to measure intraocular pressure (IOP) in intact, healthy guinea pigs (15 male, 15 female) every 2 h for a 24-h period. First, IOP was measured by using rebound tonometry (RBT). After a 1-min rest period, 0.5% proparacaine ophthalmic solution, a topical anesthetic, was applied to both eyes; 4 min after anesthetic instillation, IOP was measured by using applanation tonometry (APT). The IOP was lower during the light period (0700 to 1900) than during the dark phase (2000 to 0600). The lowest IOP by both RBT and APT (3.68 and 13.37 mm Hg, respectively) occurred at 0700, whereas maximal IOP occurred at 2300 for RBT (8.12 mm Hg) but at 2100 for APT (20.62 mm Hg). No significant differences in IOP between the left and right eyes or between RBT and APT were noted. In addition, daily variations in the IOP of guinea pigs seem to be independent of sex and body weight. The results of this study may be beneficial in the diagnosis and observation of glaucoma in guinea pigs.

Here we describe a case of pseudopregnancy in a New Zealand White rabbit as a result of pair housing with an aggressive conspecific. Clinical signs included fur pulling and nest building that developed shortly after separation from the aggressor. An ovariohysterectomy was performed, and histopathologic findings support the diagnosis of pseudopregnancy. When introducing adult female rabbits to pair housing, stable pairs may be difficult to achieve because of the dominance-associated behavior that can occur as hierarchal relationships are formed. Does that are pair-housed after puberty should be monitored for aggressive behavior.