We investigated the role of water features as focal attractors for gray foxes (Urocyon cinereoargenteus), coyotes (Canis latrans), and bobcats (Felis rufus) in west Texas to determine if they were foci for interspecific interaction. Mixed effects models indicated that species partitioned use of water features spatially and temporally. Linear models indicated factors influencing relative activity at water features varied by species. For coyotes and bobcats, the water availability model, containing days since last rainfall and nearest‐neighbor distance to water was best supported by the data, with relative activity increasing with time between rainfall and distance between waters. For gray foxes, the best approximating model indicated that relative activity was inversely correlated to coyote and bobcat activity indices, and positively correlated to topographical complexity. Encounters between carnivore species were low, with most occurring between coyotes and gray foxes, followed by coyotes and bobcats, and bobcats and gray foxes. These findings suggest a behavioral‐environmental mechanism that may function to modulate resource partitioning by carnivores in the arid West. © 2011 The Wildlife Society.

Little is known about the immunogenicity of RABORAL V-RG(®) (V-RG), an oral rabies vaccine, in raccoon kits (Procyon lotor). The objectives of this study were to characterize the immunogenicity of V-RG in young kits and investigate the potential impact of maternal antibodies on response to vaccination of nursing raccoon kits. Raccoon kits (n=30) were vaccinated at either 3 weeks of age, 7 weeks of age, or assigned as contact controls. Nineteen kits (73%) that were whelped by unvaccinated mothers responded to V-RG exposure (orally or indirect contact) by production of detectable rabies virus neutralizing antibodies (RVNA) while 7 (27%) kits did not respond to V-RG exposure. Four kits were whelped by a mother with high levels of RVNA and all four kits acquired maternal rabies antibodies. At approximately 9 months of age, all kits were inoculated with a killed rabies vaccine, IMRAB3(®). The kits which initially responded to V-RG oral vaccination or contact with vaccinated littermates demonstrated a rapid anamnestic response. In contrast, the V-RG non-responders and those with acquired maternal antibodies exhibited a primary immune response to IMRAB3(®), where RVNA levels were substantially lower on days 5 and 7 than the levels in the animals with an anamnestic response. These findings suggest that the naïve contact kits and the nonresponsive kits most likely remained susceptible to rabies virus infection whereas the ones demonstrating response to V-RG would not have been susceptible to a rabies virus infection.

ABSTRACT:As coyotes (Canis latrans) adapt to living in urban environments, the opportunity for cross-species transmission of pathogens may increase. We investigated the prevalence of antibodies to pathogens that are either zoonotic or affect multiple animal species in urban coyotes in the Denver metropolitan area, Colorado, USA, in 2012. We assayed for antibodies to canine parvovirus-2, canine distemper virus, rabies virus, Toxoplasma gondii, Yersinia pestis, and serotypes of Leptospira interrogans. Overall, 84% of the animals had antibodies to canine parvovirus-2, 44% for canine distemper virus, 20% for T. gondii (IgG), 28% for Y. pestis, and 4% for L. interrogans serotype Grippotyphosa. No neutralizing antibodies were detected to rabies virus, T. gondii (IgM), or L. interrogans serotypes other than Grippotyphosa. With 88% of animals exposed to at least one pathogen, our results suggest that coyotes may serve as important reservoirs and sentinels for etiologic agents.

Leptospirosis is a zoonotic disease caused by the bacterium Leptospira interrogans. The organism is typically maintained within a geographic region by colonizing renal tubules of carrier animals and shed into the environment in urine. We assessed whether L. interrogans was present in fox squirrels (Sciurus niger) in Larimer County, Colorado, USA, and whether it is associated with disease. Twenty-two squirrels were trapped from 29 November 2011 to 15 December 2011 for use in an unrelated study. The squirrels were individually housed for 33-65 days and euthanized; no clinical disease was observed. On gross examination, significant renal lesions were observed in 6 of 22 animals (27%). Histologically, affected animals had severe neutrophilic tubulitis with interstitial nephritis. Immunohistochemistry was conducted on the kidneys of all animals and 10 of 22 (45%) were positive for L. interrogans, with varying severity of infection. The same 10 squirrels were serologically positive for antibodies specific to L. interrogans. These results suggest that L. interrogans is present in fox squirrels in Larimer County, Colorado, USA, and may be associated with varying degrees of renal disease. Further investigation into the role of wildlife in the ecology of leptospirosis within the region is warranted.

Accurate reference intervals (RIs) for commonly measured blood-based analytes are essential for health monitoring programmes. Baseline values for a panel of analytes can be used to monitor physiologic and pathophysiologic processes such as organ function, electrolyte balance and protein catabolism. Our reference population includes 651 serum samples from polar bears (Ursus maritimus) from the southern Beaufort Sea (SB) subpopulation sampled in Alaska, USA, between 1983 and 2016. To establish RI for 13 biochemical analytes, we defined specific criteria for characterizing the reference population and relevant subgroups. To account for differences in seasonal life history characteristics, we determined separate RI for the spring and fall seasons, when prey availability and energetic requirements of bears differ. We established RI for five subgroups in spring based on sex, age class and denning status, and three subgroups in fall based on sex and age class in females only. Alkaline phosphatase activities were twice as high in subadult as in adult polar bears in spring (zmales = 4.08, Pmales < 0.001, zfemales = 3.90, Pfemales < 0.001) and did not differ between seasons. Denning females had significantly higher glucose concentrations than non-denning females (z = 4.94, P < 0.001), possibly reflecting differences in energy expenditure during lactation. A total of 10 of the 13 analytes differed significantly between seasons in either males or females; however, the physiologic importance of these differences may be minimal. Establishing these RIs allows for temporal monitoring of polar bear health in the SB and may prove useful for assessing and monitoring additional polar bear subpopulations in a changing Arctic environment.

ABSTRACT:RABORAL V-RGH a is a recombinant vaccine used in oral rabies vaccination (ORV) programs for wildlife in the United States. Vaccination rates for raccoons are substantially lower than vaccination rates for gray foxes and coyotes. Research suggests that the low viscosity of the oral vaccine may preclude animals from receiving an effective dose when biting into the vaccine bait delivery system. We evaluated the possibility of using two benign compounds, chitosan and N,N,Ntrimethylated chitosan (TMC), to increase the viscosity of the vaccine and potentially act as adjuvants to improve the immune response in raccoons (Procyon lotor). Forty mildly sedated raccoons were orally vaccinated via needleless syringe with either RABORAL V-RG (n512), chitosan+RABORAL V-RG (n512), TMC+ RABORAL V-RG (n512), or no vaccine (n54), on day 0 and again on day 90. We collected sera every 2-4 wk for 4 mo and evaluated rabies virus-neutralizing antibodies (rVNA). Raccoons were considered responders if rVNA titers were $0.1 IU/mL. Eleven of 12 raccoons vaccinated with TMC+RABORAL V-RG responded after one dose of vaccine, as did eight of 12 vaccinated with RABORAL V-RG, and three of 12 vaccinated with chitosan+ RABORAL V-RG. Our results suggest that the inclusion of an adjuvant, such as TMC, could increase vaccine efficacy to aid in controlling rabies virus spread in wildlife reservoirs.

ONRAB(®) is a recombinant human adenovirus type 5 (HAd5) with the rabies glycoprotein gene incorporated into its genome. ONRAB(®) has been used in Canada as an oral rabies vaccine in target wildlife species such as: red fox (Vulpes vulpes), raccoon (Procyon lotor), and striped skunk (Mepthis mephitis). We evaluated the safety of ONRAB(®) in non-target wildlife species likely to contact the vaccine baits during oral rabies vaccine campaigns in the United States. We investigated the effects of oral inoculation of high titer ONRAB(®), approximately ten times the dose given to target species, in wood rats (Neotoma spp.), eastern cottontail rabbits (Sylvilagus floridanus), Virginia opossums (Didelphis virginiana), eastern wild turkeys (Meleagris gallopavo silvestri), and fox squirrels (Sciurus niger). We performed real-time polymerase chain reaction (PCR) on fecal swabs, oral swabs, and tissues, including lung, liver, kidney, small intestine, large intestine, and when appropriate nasal turbinates, to detect ONRAB(®) DNA from inoculated animals. By seven days post-inoculation, turkeys, opossums, and cottontails had all stopped shedding ONRAB(®) DNA. One wood rat and one fox squirrel still had detectable levels of ONRAB(®) DNA in fecal swabs 14 days post-inoculation. Real-time PCR analysis of the tissues revealed some ONRAB(®) DNA persisting in certain tissues; however, there were no significant gross or histologic lesions associated with ONRAB(®) in any of the species studied. Our results suggest that many non-target species are not likely to be impacted by the distribution of ONRAB(®) as part of oral rabies vaccination programs in the United States.

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