Laboratory animal science
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Laboratory animal science · Oct 1994
Epidural catheter placement for testing of obstetrical analgesics in female guinea pigs.
The pregnant guinea pig may be a useful model for the study of drug effects in the newborn. A reliable technique for epidural catheterization in the guinea pig was developed to allow use of this model to evaluate the effects of epidural labor analgesics on neonates. Catheters were implanted in two open pilot animals and 19 time-dated pregnant animals on days 59 to 62 of gestation. ⋯ Failed catheters were either subdural, with one catheter found to be penetrating the spinal cord (intraspinal), or intramuscular. Response to epidurally administered bupivacaine was variable but was typically characterized by normal alertness and ability to use the forelimbs; depression of the panniculus reflex in the dorsal lumbar region; and hind limb motor impairment, with ataxia, loss of the placing reflex, and a tendency to drag the hind limbs. Subdural placement was associated with CNS depression, recumbency, shallow breathing, and sensory block ascending to the level of the ears.(ABSTRACT TRUNCATED AT 250 WORDS)
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Laboratory animal science · Dec 1993
Estrus detection by using vaginal cytologic examination in miniature swine.
Vaginal smears were obtained from four Yucatan miniature swine daily for 69 days and stained with hematologic stain. Epithelial cells were categorized as superficial, large intermediate, small intermediate, or parabasal. Leukocytes were also quantitated. ⋯ Further, epithelial cells were at their peak during estrus, decreasing markedly during diestrus, and increasing again during proestrus. The combined superficial plus large intermediate cell counts were significantly higher during estrus than during diestrus or proestrus. We conclude that daily vaginal smears can be used to determine the stage of estrus in Yucatan pigs.
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Laboratory animal science · Dec 1993
Anesthetic potency and cardiopulmonary effects of enflurane, halothane, and isoflurane in goats.
Anesthetic requirements, as defined by the minimum alveolar anesthetic concentration (MAC) that prevents gross, purposeful movement in 50% of animals, have not been determined in goats. Therefore, we determined anesthetic potency of enflurane (N = 6), halothane (N = 8), and isoflurane (N = 7) in goats by using the tail clamp and dew-claw clamp as the noxious stimuli and then measured the cardiovascular and respiratory effects of these agents. ⋯ During spontaneous breathing, respiratory depression was manifested by apnea in two animals and an elevated PaCO2: 57 +/- 15 mm Hg, 55 +/- 13 mm Hg, and 59 +/- 14 mm Hg, respectively, for enflurane, halothane, and isoflurane. Minute ventilation during spontaneous breathing was approximately 50% of controlled ventilation for each anesthetic agent.(ABSTRACT TRUNCATED AT 250 WORDS)
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Laboratory animal science · Oct 1992
Evaluation of greyhound susceptibility to malignant hyperthermia using halothane-succinylcholine anesthesia and caffeine-halothane muscle contractures.
We investigated Greyhounds because of prior reports of malignant hyperthermia (MH) episodes and because Greyhounds may express high genetic relatedness due to inbreeding for generations. Seven Greyhound and six mongrel dogs were given halothane and succinylcholine anesthesia as a challenge to trigger MH. They also underwent semitendinosus muscle biopsy for contracture study with halothane and caffeine. ⋯ Neither mongrels nor this group of Greyhounds were obviously susceptible to MH. If all Greyhounds are genetically homologous, then Greyhounds may not be specifically MH susceptible. These findings overall may provide a protocol and baseline normal comparative data for determining MH susceptibility in dogs and other species.