MousePZT: A simple, reliable, low-cost device for vital sign monitoring and respiratory gating in mice under anesthesia.

Small animal studies in biomedical research often require anesthesia to reduce pain or stress experienced by research animals and to minimize motion artifact during imaging or other measurements. Anesthetized animals must be closely monitored for the safety of the animals and to prevent unintended effects of altered physiology on experimental outcomes. Many currently available monitoring devices are expensive, invasive, or interfere with experimental design. Here, we present MousePZT, a low-cost device based on a simple piezoelectric sensor, with a custom circuit and computer software that allows for measurements of both respiratory rate and heart rate in a non-invasive, minimal contact manner. We find the accuracy of the MousePZT device in measuring respiratory and heart rate matches those of commercial systems. Using the widely-used gas isoflurane and injectable ketamine/xylazine combination, we also demonstrate that changes in respiratory rate are more easily detected and can precede changes in heart rate associated with variations in anesthetic depth. Additional circuitry on the device outputs a respiration-locked trigger signal for respiratory-gating of imaging or other data acquisition and has high sensitivity and specificity for detecting respiratory cycles. We provide detailed instruction documents and all necessary microcontroller and computer software, enabling straightforward construction and utilization of this device.

Novel extracellular matrix wound dressing shows increased epithelialization of full-thickness skin wounds in dogs.

OBJECTIVE: To compare the differences in the healing of surgically created full-thickness wounds in dogs treated with a novel extracellular matrix (ECM) dressing as compared with a standard wound management protocol and to investigate the effect of antibiotics in these 2 populations. ANIMALS: 15 purpose-bred Beagles, 8 female spayed and 7 males neutered, operated on, and monitored between March 14, 2022, and April 18, 2022. METHODS: Four 2 X 2-cm full-thickness skin wounds were created on the trunks of each dog. The right-sided wounds were treated with the novel ECM wound dressing, and the left-sided wounds served as the controls. Wound planimetry and qualitative wound scores were obtained at 12 time points. Wound biopsies for histopathologic assessment of wound repair and wound inflammation were obtained at 6 time points. RESULTS: Wounds treated with ECM had higher percent epithelization at days 7, 9, 12, and 18 postoperatively (P < .001) and better histologic repair scores (P = .024) than wounds treated by the standard protocol. Subjective wound assessment scores of wounds treated with ECM did not differ from those treated by the standard protocol at any time point. CLINICAL RELEVANCE: Wounds treated with the novel ECM dressing epithelialized more rapidly than wounds treated by a standard protocol.