Ratite anesthetic events are often dangerous because these birds use their powerful legs and clawed feet as a defense, and physical restraint can result in self-trauma or injury to handlers. Although various combinations of opioids, alpha-2 adrenergic agonists, and dissociative agents have been employed in ratites, few effective chemical immobilization protocols have been documented for rheas (Rhea spp.). An intramuscular, remote-delivered combination of thiafentanil (0.30 +/- 0.08 mg/kg), dexmedetomidine (7.31 +/- 2.72 microg/kg), and tiletamine-zolazepam (5.09 +/- 2.31 mg/kg) was utilized in eight adult (four male, four female) greater rheas (Rhea americana). Smooth inductions were observed. During clinical procedures, birds were intubated and maintained on isoflurane gas, and atipamezole was administered to antagonize the dexmedetomidine. At recovery, naltrexone was administered to antagonize the thiafentanil, and midazolam was administered to smooth crate recoveries until release. This low-volume, high-potency, reversible drug combination demonstrated safe inductions and smooth recoveries and proved to be a reliable anesthetic regimen for greater rheas.

Transplantation of cellular populations to facilitate regrowth of damaged axons is a common experimental therapy for spinal cord injury. Schwann cells (SC) or microglia grafted into injury sites can promote axonal regrowth of central projections of dorsal root ganglion (DRG) sensory neurons. We sought to determine whether the addition of microglia or microglia-derived secretory products alters DRG axon regrowth upon cultures of SC. Rat DRG explants were grown on monolayers consisting of either SC, microglia, SC exposed to microglia-conditioned medium (MCM), or co-cultures with different relative concentrations of microglia. Image analysis revealed that, compared to SC alone, the extent of neurite outgrowth was significantly greater on SC-microglia co-cultures. Immunocytochemistry for extracellular matrix molecules showed that microglial cells stained positively for growth-promoting thrombospondin, whereas laminin and the inhibitory chondroitin sulfate proteoglycans (CSPGs) were localized primarily to SC. Notably, immunoreactivity for CSPGs appeared reduced in areas associated with DRG outgrowth in co-cultures and SC exposed to MCM. These results show that microglia or their secreted products can augment SC-mediated DRG regrowth in vitro, indicating that co-grafting SC with microglia provides a novel approach to augment sensory fiber regeneration after spinal cord injury.

Rodents and other small wild mammals are often considered to be pests and vectors for disease in zoos that house small populations of valuable threatened and endangered animals. In 2005, three nonhuman primates at a drive-through zoo in Oregon, US, acquired tularemia from an unknown source. Due to an abundance of California ground squirrels ( Spermophilus beecheyi ) on zoo grounds, we instituted serosurveillance of this species from July through September 2008 to determine the prevalence of antibodies against pathogens considered to be potentially transmissible to collection animals. Serologic testing was performed for Francisella tularensis ; Leptospira interrogans serovars Canicola, Grippotyphosa, Hardjo, Icterohemorrhagiae, and Pomona; Toxoplasma gondii ; and Yersinia pestis . All squirrels were seronegative for Yersinia pestis (0%; 0/45) and Toxoplasma gondii (0%; 0/20); there was a prevalence of 2% (1/45) for Francisella tularensis antibodies and 57% (24/42) were positive for various Leptospira serovars. Although it remains unclear whether ground squirrels present a significant risk for transmission of disease to zoo animals, vaccination of high-risk zoo animals against leptospirosis warrants consideration. Beyond this, continued vigilance and persistence with various forms of pest control may reduce the likelihood of disease transmission from wildlife hosts to animals in human care.