Jeffrey M. B. Musser

Development of a contagious ecthyma vaccine for goats

OBJECTIVE To identify a strain of contagious ecthyma virus from goats that possesses the appropriate characteristics for an effective vaccine for goats. ANIMALS 25 goat kids used for vaccine development and 100 goat kids used for evaluation of vaccine efficacy. PROCEDURES 5 strains of contagious ecthyma virus were tested in a vaccination-challenge study to identify the best strain to be the seed strain for a contagious ecthyma vaccine. The vaccine derived from the chosen viral stain was tested at 2 concentrations for efficacy in a vaccination-challenge study. RESULTS 2 of 5 viral strains induced moderate to severe scabs following infection, and 3 viral strains protected the goats from wild-type virus challenge following vaccination. Viral strain 47CE was selected as the seed source for the production of a contagious ecthyma vaccine because of the larger vaccine-to-challenge scab formation ratio. Vaccine 47CE protected all goat kids (48/48) following challenge with the wild-type contagious ecthyma virus; all goat kids (32/32) in the control group had scab formation following challenge with the wild-type contagious ecthyma virus, which indicated no protection following administration of vaccine diluent. CONCLUSIONS AND CLINICAL RELEVANCE A vaccine containing a caprine strain of contagious ecthyma virus used in goats appeared to provide the characteristics needed for an effective vaccine, including good scab production and protection from wild-type infection. This vaccine may potentially provide better protection for goats from contagious ecthyma than currently available vaccines labeled for sheep.

Use of serology and bacterial culture to determine prevalence of Brucella spp. In feral Swine (sus scrofa) in proximity to a beef cattle herd positive for Brucella suis and Brucella abortus.

Using serology and bacterial culture, we determined the prevalence of Brucella spp. and the antibody to Brucella spp. in a feral swine (Sus scrofa) population in proximity to a cattle herd that was culture positive for Brucella abortus and Brucella suis in north-central Texas, USA. During a prospective cross-sectional quantitative study in April 2005, we collected blood and tissue samples from 40 feral swine within a 30-km radius of the infected herd. Serum samples were tested by the Rose Bengal test, particle concentration fluorescence immunoassay, and fluorescence polarization assay. In addition, tissue samples were cultured, and the Brucella species and biovar determined. Four feral swine were Brucella positive by serology, and two were culture positive for B. suis biovar 1. Of the culture-positive swine, one was concurrently antibody and culture positive, and one was culture positive only. The presumptive source of the B. suis infection in the index cattle herd was likely the surrounding feral swine population. Because B. abortus was not cultured from the feral swine, it is unlikely that the source of the B. abortus infection in the index herd originated from the feral swine. Endemic diseases in feral swine populations can pose a disease threat to livestock and a zoonotic risk to humans.

Efficacy of an Anaerobic Swab Transport System to Maintain Aerobic and Anaerobic Microorganism Viability after Storage at −80°C

An Amies agar gel swab transport system was evaluated for its ability to maintain bacterial viability and relative quantity after freezing at −80°C. Nine American Type Culture Collection (ATCC) bacterial strains were used: 3 anaerobic strains (Propionibacterium acnes, Peptostreptococcus anaerobius, and Clostridium sporogenes) and 6 facultative or strict aerobic bacterial strains (Stenotrophomonas maltophilia, Escherichia coli ([ATCC 25922 and ATCC 11775], Salmonella enterica subsp. enterica serovar Typhimurium, Staphylococcus saprophyticus, and Lactobacillus casei). The bacterial species were chosen because they corresponded to bacteria identified in psittacine feces and cloacal samples. There were no significant differences between growth scores at baseline and after storage at −80°C for 40 days for any of the bacteria examined after 48 and 72 hr of incubation, with the exception of P. anaerobius. For P. anaerobius, there was a significant reduction (P < 0.001) in the growth score after storage at −80°C for 40 days from that of the baseline; however, the bacteria were still viable. The tested swab transport system may be useful when lengthy storage and transport times necessitate freezing samples prior to culture.

Pharmacokinetic differences in exposure to camphor after intraruminal dosing in selectively bred lines of goats

A pharmacokinetic dosing study with camphor was used to determine whether selection lines of high-juniper-consuming goats (HJC, n = 12) and low-juniper-consuming goats (LJC, n = 12) differed in their respective disposition kinetics. Postdosing plasma camphor concentrations were used to examine whether a timed single blood sample collected after intraruminal administration of camphor would be a useful screening test to aid in the identification of HJC. Yearling female Boer x Spanish goats (n = 24) received a single intraruminal dose of monoterpene cocktail (0.270 g/kg of BW) containing 4 different monoterpenes that represented their composition previously reported for Ashe juniper (Juniperus ashei). Camphor, the predominant monoterpene in Ashe juniper, was 49.6% of the mix and was the monoterpene analyzed for this study. Blood samples were taken at 15 time points from 0 to 8 h after dosing. Concentrations of camphor were measured in plasma using solid phase extraction and gas chromatography/flame-ionization detection analysis. Maximal plasma concentration of camphor was greater for LJC than HJC (P = 0.01), and area under the curve extrapolated to infinity was greater for LJC than HJC (P < 0.01). Total systemic exposure (area under the curve) to camphor was 5 times less in HJC goats. We conclude that 1) HJC goats possess internal mechanisms to reduce the bioavailability of camphor, and 2) a blood sample taken at 45 min or at 60 min after intraruminal administration of camphor may be useful for identifying HJC individual animals from within large populations of goats.

Pharmacokinetics after intravenous administration of flunixin meglumine in budgerigars (Melopsittacus undulatus) and Patagonian conures (Cyanoliseus patagonus)

OBJECTIVE To investigate the disposition kinetics of flunixin meglumine when administered IV to budgerigars (Melopsittacus undulatus) and Patagonian conures (Cyanoliseus patagonus). DESIGN Prospective cohort study. ANIMALS 8 adult Patagonian conures and 24 adult budgerigars. PROCEDURES Injectable flunixin meglumine (50 mg/mL) was diluted to 10 and 1. 0 mg/mL and administered IV at a dose of 5.0 mg/kg (2.3 mg/lb) to Patagonian conures and budgerigars, respectively. RESULTS In budgerigars, the elimination half-life was 0.72 hours and the mean residence time was 0.73 hours. In Patagonian conures, the elimination half-life was 0.91 hours and the mean residence time was 1.20 hours. The concentration of flunixin was below the assays limit of quantification (0.5 μg/mL) at 3 and 6 hours in budgerigars and Patagonian conures, respectively. A single budgerigar developed adverse effects (lethargy and signs of depression) for approximately 15 minutes following drug administration. CONCLUSIONS AND CLINICAL RELEVANCE The half-life of flunixin in Patagonian conures and budgerigars was short following IV administration; however, results of this study suggested that IV administration of injectable flunixin meglumine at 5.0 mg/kg resulted in plasma concentrations that could potentially be anti-inflammatory and analgesic in budgerigars and Patagonian conures.

Ribavirin Inhibits Parrot Bornavirus 4 Replication in Cell Culture

Parrot bornavirus 4 is an etiological agent of proventricular dilatation disease, a fatal neurologic and gastrointestinal disease of psittacines and other birds. We tested the ability of ribavirin, an antiviral nucleoside analog with antiviral activity against a range of RNA and DNA viruses, to inhibit parrot bornavirus 4 replication in duck embryonic fibroblast cells. Two analytical methods that evaluate different products of viral replication, indirect immunocytochemistry for viral specific nucleoprotein and qRT-PCR for viral specific phosphoprotein gene mRNA, were used. Ribavirin at concentrations between 2.5 and 25 μg/mL inhibited parrot bornavirus 4 replication, decreasing viral mRNA and viral protein load, in infected duck embryonic fibroblast cells. The addition of guanosine diminished the antiviral activity of ribavirin suggesting that one possible mechanism of action against parrot bornavirus 4 may likely be through inosine monophosphate dehydrogenase inhibition. This study demonstrates parrot bornavirus 4 susceptibility to ribavirin in cell culture.

Evaluation of homologous and heterologous protection induced by a virulent field strain of orf virus and an orf vaccine in goats

OBJECTIVE To evaluate cross protection provided by administration of contagious ecthyma vaccines against strains of orf virus in goats. ANIMALS 126 Boer-Spanish crossbred goats (3 to 20 days old). PROCEDURES 85 goats were vaccinated with a goat-derived contagious ecthyma vaccine. Of these, 41 were challenge exposed with the virus strain for the contagious ecthyma vaccine, 40 were challenge exposed with a more virulent field strain of orf virus, and 4 were lost to predation or died. Another 41 goats were vaccinated with a vaccine produced from a more virulent field strain of orf virus; of these, 18 were challenge exposed with the virus strain of the goat-derived contagious ecthyma vaccine, 18 were challenge exposed with the more virulent field strain of orf virus, and 5 were lost to predation or died. RESULTS Vaccination with the goat-derived contagious ecthyma vaccine did not significantly reduce the number of goats with lesions or lesion severity caused by challenge exposure with the more virulent field strain of orf virus. Vaccination with the vaccine produced from the more virulent field strain of orf virus significantly reduced the number of goats with lesions attributable to challenge exposure with the virus strain of the goat-derived contagious ecthyma vaccine, but it failed to significantly reduce lesion severity. CONCLUSIONS AND CLINICAL RELEVANCE Vaccination did not result in cross protection for the 2 strains of orf virus. This may have been attributable to antigenic differences and may be a factor in outbreaks of contagious ecthyma in vaccinated goats.

Venous Blood Gas, Electrolyte, and Hematologic Analytes of the Mottled Duck, Anas fulvigula

Abstract We collected venous blood samples from 83 apparently healthy Mottled Ducks (Anas fulvigula) July 2012–August 2013 on the Texas, US, Gulf Coast and measured blood gas, electrolyte, biochemical, and hematologic parameters. Age, sex, body condition score, capture year, capture type, and time of day had significant statistical, but not clinically relevant, effects on several analytes. Ducks caught by rocket net had findings consistent with greater stress compared with hand-caught ducks. These analyte data for healthy free-living Mottled Ducks may be useful in the assessment of Mottled Duck population health and in the management and treatment of individual ducks affected by environmental stressors.

A gas chromatography-mass spectrometry assay to quantify camphor extracted from goat serum.

A sensitive gas chromatography-mass spectrometry (GC-MS) method was developed and validated for quantification and pharmacokinetics of camphor, a major monoterpene of juniper plant, in goat serum. Camphor and internal standard (terpinolene) eluates from solid phase extraction (SPE) with ethyl acetate yielded well resolved peaks and were clearly identified in total and selected ion chromatograms. The elution and injection volumes were optimized for improved detection and quantification of camphor based on peak shape, signal to noise ratio, recoveries, and repeatability. The matrix calibration curve with the good linearity (R(2)=0.998) and response in the range of 0.005-10.0 μg/mL was used to determine camphor concentration in goat serum. The GC-MS method offered sufficiently low limits of detection (1 ng/mL) and quantitation (3 ng/mL) for camphor concentration in goat serum for the pharmacokinetic study. The proposed method showed good intra- and inter-day variation with relative standard deviation (RSD) of 0.2-7.7% and produced good recovery (96.0-111.6%) and reproducibility (1.6-6.1%) at all spiked levels. Using this method on serum samples obtained from two goats orally dosed with camphor confirmed that the method is suitable for camphor studies in animals.

Welcome to Veterinary Medicine: Research and Reports

Correspondence: Jeffery MB Musser Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, TX, USA Tel +1 979 458 0527 Email jmusser@cvm.tamu.edu This year marks the 250th anniversary of the Royal Veterinary School in Lyon, France, the world’s first veterinary college. Since its inception, many changes have occurred in veterinary medicine such as views on education and didactic learning, demographics of our profession, and standards of practice in animal husbandry, medicine, surgery, anesthesia, and vaccinology. In fact, the concept of infectious diseases has changed – remember the germ theory was proposed a mere 140 years ago. However, one constant tenet in our profession has been the need to disseminate progresses, innovations, advances, and developments in veterinary sciences. Published reports are the foundation for the growth of medicine and science. What would the state of medicine be if Pasteur, Koch, Bourgelat, or Theobald Smith had not published their works? From the first volumes of the Veterinary Journal and Annals of Comparative Pathology and the American Veterinary Review, 1875 and 1877 respectively, which contained general veterinary news, editorials, scientific articles, and case reports, many other excellent journals have continued to circulate information to practitioners, scientists, and researchers. These journals were bound, hard copy periodicals sent to individuals and libraries that had purchased them. But, today’s technology is transforming the process of information dissemination and publishing. Computers, iPads, notebooks, and smart phones are allowing us to go paperless with more timely and extensive access to publications and information. A new model of publishing is setting the standard for periodicals – Open Access. Open Access does not charge readers or institutions for the use of the journal. The user is free to read, download, copy, share, or print articles of interest. Articles published in Open Access are available anywhere there is access to the World Wide Web, thus providing a venue for wider distribution and increased efficiency and use of the material. However, Open Access publication is only a model for distribution. Just as important, or perhaps even more important, is the quality of the information that is distributed. If a journal contains articles of low scientific merit, it is a poor quality journal and few care how easily it can be accessed or shared. So what characteristics make a “quality” journal? For simplicity’s sake, and as a food animal veterinarian I like simplicity, the characteristics of a quality journal can be listed as 1) accessibility and dissemination, 2) timeliness, and 3) article worth. So what about Veterinary Medicine: Research and Reports; is it a quality journal? On the issue of accessibility and dissemination, Open Access, as stated previously, provides a venue for wider distribution; there are no restrictions on accessing V et er in ar y M ed ic in e: R es ea rc h an d R ep or ts d ow nl oa de d fr om h ttp s: //w w w .d ov ep re ss .c om / b y 54 .7 0. 40 .1 1 on 1 1D ec -2 01 8