Journal of the American Association for Laboratory Animal Science Ahead of Print

Escherichia coli strains are the most common bacterial cause of canine neonatal mortality, with rectal and vaginal contaminants from the mother reportedly serving as an important source of infection. Between July and September 2013, a canine research facility at Michigan State University experienced a spike in neonatal mortality. Thirteen of 14 puppies from 2 litters died, with 10 being submitted for necropsy. Three puppies from one litter struggled since birth to suckle and died. Five puppies from an additional litter died after presenting due to failure to thrive, depression, and lethargy. All puppies exhibited microscopic lesions consistent with septicemia represented by interstitial necrotizing pneumonia, random hepatocellular necrosis, or intravascular bacteria. Bacterial cultures of the lung and liver yielded numerous β-hemolytic Streptococcus group G and numerous Escherichia coli, which tested positive by PCR for the cytotoxic necrotizing factor 1 (cnf1) gene. Vaginal and rectal culture swabs taken from adult breeding females between 2013 and 2020 revealed that many were asymptomatic carriers of cnf1⁺ E. coli. The institution of prophylactic antimicrobial treatment for pregnant females testing culture positive for cnf1⁺ E. coli before parturition may have prevented additional puppy losses; however, it may have also contributed to resistance observed in future samples. While increased attention to pregnant females testing positive for cnf1⁺ E. coli prevented subsequent neonatal mortality, the source of the pathogen was not identified. More in-depth sampling of the facility environment could identify a reservoir; however, endemic carriers cannot be ruled out. Screening protocols may be warranted in facilities experiencing persistent cnf1⁺ E. coli infections.

Warmed inspired air circuits have proved to be effective in semiclosed heating modalities in veterinary species such as dogs, cats, and nonhuman primates, and thus, there is a gap in species requiring a nonrebreathing circuit. This study evaluated the efficacy of using warmed inspired air in addition to conductive mattress warming in the prevention of hypothermia in anesthetized rabbits (Oryctolagus cuniculus). Rabbits were divided into 2 groups: conductive warming only (control) or conductive warming and warmed inspired air. Our results showed that the addition of a warmed air anesthesia circuit had a significant positive effect on perianesthetic body temperature, maintaining a higher rectal temperature starting 10 minutes after induction and a higher final rectal temperature after a 45-minute anesthetic procedure. At 20 minutes after induction, the body temperature of the warmed air group was not significantly different from baseline compared with a significant drop from baseline in the control group. Infrared pinnal temperatures did not show a pairwise significance in the effect of heating modality and time; however, a clinically significant difference of 2-3 °F between groups was seen. There were no statistically significant differences between groups for time to full recovery and time to extubation. For procedures using rabbits, the addition of warmed inspired air should be considered a significant refinement that promotes normothermia during anesthesia based on consistent and improved overall body temperatures.

Injectable anesthetics are commonly used in murine experimental procedures. However, these agents may result in neurotoxicity, which should be considered in interpretation of experimental results. We evaluated acute effects of 2 different anesthetic combinations on juvenile mouse brain development using structural MRI to assess impact on the brain. We compared the use of ketamine-xylazine, a commonly used injectable anesthetic combination in mice, to alfaxalone-xylazine in the context of noninvasive procedures requiring immobilization (that is, not a surgical plane of anesthesia). In this longitudinal study, we used MRI to produce three-dimensional scans of mouse brains at 2 time points (postnatal days 14 and 23), analogous to early childhood to prepubescence in humans. At postnatal day 16, mice were either dosed with ketamine-xylazine, alfaxalone-xylazine, or left untreated. From the scans, we quantified whole brain and structure volumes across the brain, comparing growth between time points and modeling the effect of both anesthetics compared with controls. Anesthetic parameters were measured, and general health and welfare were monitored during and after each injectable anesthesia drug condition. Results indicate that systemic and brain toxicity were reduced in mice treated with alfaxalone-xylazine compared with ketamine-xylazine. In addition, both ketamine-xylazine and alfaxalone-xylazine reliably anesthetized all mice, although mice administered ketamine-xylazine showed increased weight loss compared with the alfaxalone-xylazine in the postanesthetic period. These findings highlight alfaxalone-xylazine as a convenient and possibly safer alternative anesthetic for mouse brain development studies when compared with ketamine-xylazine and as a viable option as an injectable anesthetic in juvenile mice.

Purpose

The Association of Primate Veterinarians (APV) recognizes that primates housed in a research setting may be susceptible to weight fluctuations that can affect their welfare and research outcomes. Obesity and poor body condition can occur spontaneously, from mismatches between food provided and caloric requirements, and/or secondary to research aims. These guidelines provide recommendations for managing research NHPs that have a non-ideal body condition to maximize their health and welfare.

Background

NHPs in research settings require an appropriate diet to support healthy development, consistent maintenance, and optimal welfare. Veterinary and research staff involved in weight management of NHPs can use

Efficacy of Warmed Inspired Air for Prevention of Perianesthetic Hypothermia in New Zealand White Rabbits (Oryctolagus cuniculus)

Alyssa H BalzerDVM, DACVPM,

Sorana RaiciulescuMSc,

William R FuginaDVM, DACVPM,

Alexis M BergBS,

Tesfaye A MekonnenLATG,

Dawn M WolfBS, LAT,

Enork E CharleusLAT, and

Cara P ReiterDVM, MPH, DACVPM, DACLAM

Case Report: The Endemic Spread of Escherichia coli Positive for Cytotoxic Necrotizing Factor Type 1 in a Canine Research Facility and Impact of Infection in Neonatal Puppies

Shaina FurmanDVM,

Julia M McIntoshBS,

Elis Arden FiskDVM,

Kristin L KoehlBS, LVT, MS,

Christine D HarmanBS,

Kimberly D WilliamsonBS, LVT, RLATg,

Janice R QuerubinLVT,

Jacquelyn M Del ValleDVM, DACLAM,

Victoria E WatsonDVM, PhD, DACVP,

Rinosh ManiBVSc, MS, PhD, DACVM,

András M KomáromyDrMedVet, PhD, DACVO, DECVO, FARVO, and

Elizabeth HamiltonMPH, PhD

Case Report: The Endemic Spread of Escherichia coli Positive for Cytotoxic Necrotizing Factor Type 1 in a Canine Research Facility and Impact of Infection in Neonatal Puppies

Efficacy of Warmed Inspired Air for Prevention of Perianesthetic Hypothermia in New Zealand White Rabbits (Oryctolagus cuniculus)

Neurodevelopmental Impacts of Ketamine and Alfaxalone Anesthesia Evaluated with Mouse MRI

Between Prometheus and Thanatos: Reflections on Intracardiac Injection Models for Metastasis in Mice

De Novo Serum Biochemistry and Electrophoretic Reference Intervals for Jamaican Fruit Bats (Artibeus jamaicensis)

Determining A1C Normal Values in Rhesus Macaques (Macaca mulatta)

Extended Sanitization Frequency for Bottles: Using Volume as an Alternative to Time-Scheduled Replacements for Mice in Disposable Individually Ventilated Caging Systems

Schistosoma mansoni Infection in Three Green Monkeys (Chlorocebus sabaeus) Originating from Saint Kitts

Spontaneous Hemangiosarcoma of Bone with Hepatic and Pulmonary Metastasis in a Rhesus Macaque (Macaca mulatta): A Case Report

Tiletamine-Zolazepam for Total Intravenous Anesthesia in Sheep

Association of Primate Veterinarians Guidelines for Weight Management in Research Nonhuman Primates

Purpose

Background

Effects of Long-Term Carprofen and Omeprazole Administration in C57BL/6J Mice

Iridophoroma in Leopard Geckos (Eublepharis macularius): Clinical Complications and Histopathology

Metabolic Cage Analysis of Surgically Catheterized C57BL/6J Mice (Mus musculus) Treated with Carprofen and Sustained-Release Buprenorphine

Mouse Papillomavirus Outbreak in a Research Facility

A Novel Strategy to Mitigate Corynebacterium bovis–Associated Hyperkeratosis in Athymic Nude Mice

Pharmacokinetic Analysis of Sustained-Release Buprenorphine Formulations in Owl Monkeys (Aotus spp.)

Pharmacokinetic Evaluation of Topical Long-Acting Buprenorphine in New Zealand White Rabbits (Oryctolagus cuniculus)

Serum Pharmacokinetics of a Highly Concentrated Buprenorphine Formulation in Older Female Sprague–Dawley Rats (Rattus norvegicus)

Subcutaneous Buprenorphine Is an Acceptable Preoperative Analgesic in Pregnant Ewes Undergoing Hysterotomy (Ovis aries)

Abdominal Distension in an Aged Female Mouse (Mus musculus)

History

Efficacy and Impact of Prophylactic Compared with Symptomatic Amoxicillin, Azithromycin, or Trimethoprim/Sulfamethoxazole Administration on Corynebacterium bovis Infection in NSG Mice (Mus musculus)

Lessons Learned from Monitoring Adeno-Associated Virus-9 Neutralizing Antibody (AAV9-NAb) Seroconversion in a Cohort of Cynomolgus Macaques (Macaca fascicularis)

Comparison of Thermal and Mechanical Pain Testing Modalities in Sprague Dawley and Fischer 344 Rats (Rattus norvegicus)

Abstract

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Efficacy of Warmed Inspired Air for Prevention of Perianesthetic Hypothermia in New Zealand White Rabbits (Oryctolagus cuniculus)

Case Report: The Endemic Spread of Escherichia coli Positive for Cytotoxic Necrotizing Factor Type 1 in a Canine Research Facility and Impact of Infection in Neonatal Puppies

Neurodevelopmental Impacts of Ketamine and Alfaxalone Anesthesia Evaluated with Mouse MRI

Tiletamine-Zolazepam for Total Intravenous Anesthesia in Sheep

Schistosoma mansoni Infection in Three Green Monkeys (Chlorocebus sabaeus) Originating from Saint Kitts

Short-Term Storage and Transport at Cold Temperatures of 2-Cell Mouse Embryos Produced by Cryopreserved Sperm

Serologic Prevalence of MPV1 in Mouse Strains in a Commercial Laboratory Mouse Colony Determined by Using VP1 Antigen

Comparison of Carbon Dioxide and Argon Euthanasia: Effects on Behavior, Heart Rate, and Respiratory Lesions in Rats

Spontaneous Staphylococcus xylosus Infection in Mice Deficient in NADPH Oxidase and Comparison with Other Laboratory Mouse Strains

Treatment and Eradication of Murine Fur Mites: I. Toxicologic Evaluation of Ivermectin-Compounded Feed