LETHAL TOXIN NEUTRALIZING ANTIBODY RESPONSE INDUCED FOLLOWING ORAL VACCINATION WITH A MICROENCAPSULATED BACILLUS ANTHRACIS STERNE STRAIN 34F2 VACCINE PROOF-OF-CONCEPT STUDY IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS).

Improved methods are needed to prevent wildlife deaths from anthrax. Caused by Bacillus anthracis, naturally occurring outbreaks of anthrax are frequent but unpredictable. The commercially available veterinary vaccine is labeled for subcutaneous injection and is impractical for large-scale wildlife vaccination programs; therefore, oral vaccination is the most realistic method to control and prevent these outbreaks. We reported the induction of an anthrax-specific lethal toxin (LeTx) neutralizing antibody response in mice following oral vaccination with alginate microcapsules containing B. anthracis Sterne strain 34F2 spores, coated with poly-L-lysine (PLL) and vitelline protein B (VpB). We continued evaluating our novel vaccine formulation through this proof-of-concept study in white-tailed deer (WTD; Odocoileus virginianus; n = 9). We orally vaccinated WTD via needle-free syringe with three formulations of the encapsulated vaccine: 1) PLL-VpB-coated microcapsules with 107-8 spores/ml (n = 5), 2) PLL-VpB-coated microcapsules with 109-10 spores/ml (n = 2), and 3) PLL-coated microcapsules with 109-10 spores/ml (n = 2). Although the limited sample sizes require continued experimentation, we observed an anthrax-specific antibody response in WTD serum following oral vaccination with PLL-coated microcapsules containing 109 spores/ ml. Furthermore, this antibody response neutralized anthrax LeTx in vitro, suggesting that continued development of this vaccine may allow for realistic wildlife anthrax vaccination programs.

In Vitro Protection and Titer Duration of Anthrax-Specific Antibodies Following Subcutaneous Vaccination of White-tailed Deer (Odocoileus virginianus) with Bacillus anthracis Sterne 34F2 Strain Spores.

Outbreaks of anthrax, caused by the soilborne bacterium Bacillus anthracis, are a continuous threat to free-ranging livestock and wildlife in enzootic regions of the United States, sometimes causing mass mortalities. Injectable anthrax vaccines are commercially available for use in livestock, and although hand injection is not a cost- or time-effective long-term management plan for prevention in wildlife, it may provide a tool for managers to target selectively animals of high conservation or economic value. Vaccine-induced anthrax-specific antibody responses have been reported previously in white-tailed deer (Odocoileus virginianus), but the protective nature was not determined. In this study, five white-tailed deer were subcutaneously vaccinated with one dose (1 mL) of the Anthrax Spore Vaccine. Eight blood collections by jugular venipuncture were conducted over 146 d to measure the anthrax-specific antibody response in each deer's serum over time. Antibodies were first detected by ELISA and later with toxin neutralization assays to estimate in vitro protection. Average peak absorbance by ELISA occurred at 14 d postvaccination, whereas average peak in vitro protection occurred at 28 d postvaccination. Observed in vitro protection on average for white-tailed deer after this single-dose vaccination protocol lasted 42-56 d postvaccination, although three individuals still maintained lethal toxin-neutralizing serum antibody titers out to 112 d postvaccination. Vaccination responses were variable but effective to some degree in all white-tailed deer.

Self-limiting Orbital Emphysema Following Ocular Evisceration and Demonstration of Nasolacrimal-Oropharyngeal Communication in a South African Ostrich (Struthio camelus australis).

A 25-year-old, male, sanctuary-owned, South African ostrich (Struthio camelus australis) was evaluated for orbital emphysema after evisceration of a nonvisual and chronically irritated eye. On initial ophthalmic examination, the ostrich's left eye displayed severe corneal fibrosis, broad anterior synechia, and a shallow anterior chamber, all suggestive of a previous corneal perforation. Conjunctival hyperemia and eyelid crusts were also present, reportedly associated with chronic rubbing. Evisceration of the left eye was performed by excising the eyelid margins, conjunctiva, nictitans, cornea, and intraocular contents. Four weeks postoperatively, a nonpainful, fluctuant swelling of the surgical site was noted. Trocarization of the surgical site verified orbital emphysema and served to temporarily decompress the orbit. Orbital emphysema reoccurred within 48 hours but gradually regressed without intervention over the subsequent 9 months. A Jones test was performed in the healthy, right eye and demonstrated clear communication to the oropharynx. To our knowledge, this is the first reported case of an evisceration performed on an ostrich and the first reported case of orbital emphysema in any avian species. It is probable that the emphysema noted in this case was secondary to nasolacrimal duct-oropharynx communication.

Seroprevalence of Borrelia burgdorferi antibodies in white-tailed deer from Texas.

Lyme Disease is caused by the bacterial pathogen Borrelia burgdorferi, and is transmitted by the tick-vector Ixodes scapularis. It is the most prevalent arthropod-borne disease in the United States. To determine the seroprevalence of B. burgdorferi antibodies in white-tailed deer (Odocoileus virginianus) from Texas, we analyzed serum samples (n = 1493) collected during the 2001-2015 hunting seasons, using indirect ELISA. Samples with higher sero-reactivity (0.803 and above) than the negative control group (0.662) were further tested using a more specific standardized western immunoblot assay to rule out false positives. Using ELISA, 4.7% of the samples were sero-reactive against B. burgdorferi, and these originated in two eco-regions in Texas (Edwards Plateau and South Texas Plains). However, only 0.5% of the total samples were sero-reactive by standardized western immunoblot assay. Additionally, both ELISA and standardized western immunoblot assay results correlated with an increased incidence in human Lyme Disease cases reported in Texas. This is the first longitudinal study to demonstrate fluctuation in sero-reactivity of white-tailed deer to B. burgdorferi sensu stricto antigens in southern United States. Future ecological and geographical studies are needed to assess the environmental factors governing the prevalence of Lyme Disease in non-endemic areas of the southern United States.

ABDOMINAL PREGNANCY IN A SERVAL (LEPTAILURUS SERVAL) SECONDARY TO UTERINE RUPTURE.

A 14-yr-old female serval (Leptailurus serval) died unexpectedly after 2 wk of inappetence and lethargy. Necropsy revealed a pyoabdomen with a full-term, well-developed fetus in the caudal abdomen covered by a mesenteric sac. The mesenteric sac communicated with a tear in the wall of the right uterine horn, supporting a diagnosis of secondary abdominal pregnancy. The uterine wall had evidence of adenomyosis at the rupture site with no evidence of pyometra. The fetus, supporting mesentery, and peritoneum were coated with mixed bacteria, which may have ascended through an open cervix to the site of uterine rupture. This is the first case of abdominal pregnancy related to uterine rupture reported in a large felid species.

DISPOSITION OF CEFTIOFUR AND ITS ACTIVE METABOLITES IN FALLOW DEER (DAMA DAMA) FOLLOWING SINGLE-DOSE INTRAVENOUS AND INTRAMUSCULAR ADMINISTRATION.

Septicemia and foot infections associated with Fusobacterium necrophorum , Pasturella multocida, and Streptococcus suis in captive fallow deer (Dama dama) are reasonably treated with ceftiofur hydrochloride. This study describes the disposition of ceftiofur after single-dose intravenous and intramuscular administration of 3.65±0.1678 mg/kg in six female adult fallow deer using a nonrandomized crossover design and a 7-day washout period. Serial blood samples were collected for 12 hr postdrug administration. Ceftiofur bioactivity, including its active metabolite desfuroylceftiofur, was quantitated in serum using a microbiologic assay. After i.v. administration, the extrapolated serum drug concentration reported as median (range) was 52.83 (43.32-57.49) µg/ml and elimination half-life was 178.36 (19.75-217.22) min. The volume of distribution at steady-state was 0.171 (0.101-0.229) L/kg and serum clearance was 0.97 (0.48-4.3) ml/min per kg. After i.m. administration, median peak plasma concentration (Cmax) was 14.37 (9.00-32.00) µg/ml at 54.5 (11.00-95.00) min. The median elimination half-life and mean residence time were 128.32 (38.03-242.40) and 203.65 (62.48-347.15) min, respectively. The median absorption time after i.m. administration was 14.77 (-57.74 to 94.79) min. Bioavailability of ceftiofur following i.m. administration was 78.00 (58.00-137.00) percent. Based on this study, a mean i.m. dose of ceftiofur of 3.65±0.1678 mg/kg every 12 hr is recommended for maintaining serum concentrations above MIC90 levels for infections associated with F. necrophorum, P. multocida, and S. suis, in addition to other susceptible infectious bacteria.