Infrared digital imaging of the equine anterior segment

Ocular photographs are an increasingly important method of documenting lesions for inclusion in medical records, teaching purposes, and research. Availability of affordable high-quality digital imaging equipment has allowed for enhanced capture of desired images because of immediate on-camera viewing and editing. Conversion of the standard digital camera sensor to one that is sensitive to infrared light (i.e. > 760 nm < 1 mm wavelength) can be done inexpensively. In the equine eye, advantages of infrared digital photography include increased contrast of anterior segment images, identification and monitoring of pigmentary changes, and increased visualization of the anterior segment through a cloudy or edematous cornea.     

Ultrasound biomicroscopy of the feline anterior segment

Ultrasound biomicroscopy was performed on enucleated feline globes as a model for use in vivo. Quantitative measurements were obtained from the anterior segment using a 50-MHz transducer. Mean values from 26 feline globes were axial corneal thickness, 0.74 mm; anterior chamber depth, 4.20 mm; distance from the first ciliary process to the limbus, 3.17 mm; angle recess, 0.38 mm; angle opening distance, 1.05 mm; iris base width 0.38 mm; iris middle width 0.52 mm; iris tip width 0.13 mm, and iris-lens overlap, 0.69 mm. Distinctive features of the feline anterior segment include a relatively wide iridocorneal angle and deep anterior chamber.     

Cecal bacterial communities in wild Japanese rock ptarmigans and captive Svalbard rock ptarmigans

Preservation of indigenous gastrointestinal microbiota is deemed to be critical for successful captivebreeding of endangered wild animals, yet its biology is poorly understood. Here, we investigated cecalbacterial communities in wild Japanese rock ptarmigans (Lagopus muta japonica) and comparedthem with those in Svalbard rock ptarmigans (L. m. hyperborea) in captivity. Ultra-deepsequencing of 16S rRNA gene indicated that the community structure of cecal microbiota in wild rock ptarmiganswas remarkably different from that in captive Svalbard rock ptarmigans. Fundamental differences betweenbacterial communities in the two groups of birds were detected at the phylum level. Firmicutes,Actinobacteria, Bacteroidetes and Synergistetes were the major phyla detected in wild Japanese rockptarmigans, whereas Firmicutes alone occupied more than 80% of abundance in captive Svalbard rock ptarmigans.Furthermore, unclassified genera of Coriobacteriaceae, Synergistaceae, Bacteroidaceae, Actinomycetaceae,Veillonellaceae and Clostridiales were the major taxa detected in wild individuals, whereas in zoo-rearedbirds, major genera were Ruminococcus, Blautia, Faecalibacterium andAkkermansia. Zoo-reared birds seemed to lack almost all rock ptarmigan-specific bacteria intheir intestine, which may explain the relatively high rate of pathogenic infections affecting them. We showevidence that preservation and reconstitution of indigenous cecal microflora are critical for successfulex situ conservation and future re-introduction plan for the Japanese rock ptarmigan.     

Post mortem magnetic resonance imaging of multiple congenital ocular anomalies in a Comtois mare

Multiple congenital ocular anomalies syndrome consists of several abnormalities mainly localised to the anterior segment of the eye. This condition, comprising iridal or ciliary cysts with or without iridal hypoplasia, an excessively protruding cornea (‘cornea globosa’), miotic pupils, retinal dysplasia, cataract, and other lesions, has been reported in several breeds and is strongly related to the silver coat colour, as a result of a dominant mutant allele at the PMEL17 locus. This report describes the macroscopic, ultrasonographic, histological and magnetic resonance imaging findings of the ocular abnormalities in a Comtois mare with multiple congenital ocular anomalies syndrome.     

Normal corneal thickness measurements in pigmented rabbits using spectral‐domain anterior segment optical coherence tomography

Objective  To document the thickness of the central cornea in pigmented rabbits using spectral‐domain anterior segment optical coherence tomography (AS‐OCT). Animals studied  Seventeen pigmented rabbits (6 male, 11 female, both eyes) were involved in this study. Procedures  Thirty‐four eyes from healthy pigmented rabbits underwent a complete ophthalmologic examination, including AS‐OCT. Eight radial scans, 6 mm in length and centered on the cornea, were obtained using the AS‐OCT. Corneal thickness was automatically calculated using pachymetry software. Measurements were displayed as the mean and standard deviation for each of the 17 regions defined by the software. The regions were the center (1 mm radius, area a), the inner ring (2.5 mm radius, area b), the outer ring (3 mm radius, area c), and the eight radial scan lines in eight directions (Superior (1), SN (2), Nasal (3), IN (4), Inferior (5), IT (6), Temporal (7), ST (8)) with an angle of 45° between each consecutive scan line (a, b 1–8, c 1–8). Results  There was no statistically significance difference in corneal thickness between gender, eye, and the eight directions (P = 0.804, P > 0.05, P > 0.05). There was a statistical difference between the thickness in areas a, b, and c (P < 0.05). The corneal thickness increased gradually from the center to the periphery of the 6 mm measured. The center corneal thickness was 387 ± 19.8 μm for OD and 384 ± 20.2 μm for OS. The corneal thicknesses of the thinnest point of the right eyes (OD) and the left eyes (OS) were 376 ± 20.2 and 370 ± 16.8 μm, respectively. There was positive correlation between the thinnest point and area a in both the right eyes (r = 0.892, P < 0.001) and the left eyes (r = 0.832, P < 0.001). Conclusions  This is the first documentation of the rabbit corneal thickness in vivo using the spectral‐domain AS‐OCT. Pigmented rabbit corneas were almost 150 μm thinner than human corneal values. Gender and eye were not associated with any statistical differences in central corneal thickness in this study.     

Anterior segment dysmorphogenesis of the eye and glaucoma in MG-W gerbils

Unilaterally swollen eyes were histopathologically characterized in four MG-W gerbils. The primary lesions resided in the anterior segment of the eye where neural crest cells play a critical role in embryonic development. They included indistinct filtration angle, unformed canal of Schlemm, hypoplastic iris, and ciliary body. The findings noted in the retina, optic nerve, optic tract, and lateral geniculate nucleus were consistent with the lesions induced following the persistent elevation of intraocular pressure as a result of insufficient drainage of aqueous humor. Thus, the present cases observed in the eyes of MG-W gerbils exemplified the anterior segment dysmorphogenesis associated with inadequate neural crest migration or differentiation, leading to subsequent glaucoma.     

Effects of unilateral topical administration of 0.5% tropicamide on anterior segment morphology and intraocular pressure in normal cats and cats with primary congenital glaucoma

Objective To determine the effects of topical 0.5% tropicamide on anterior segment morphology (ASM) and intraocular pressure (IOP) in normal and glaucomatous cats. Animals used Normal cats and cats with inherited primary congenital glaucoma (PCG). Procedures Control IOP curves were performed in untreated normal and PCG cats. In the first experiment, tropicamide was applied OD in eight normal and nine PCG cats. IOP and pupillary diameter (PD) were measured at 0, 30, and 60 min, then hourly until 8 h post‐treatment. In a second experiment, six normal and seven PCG cats received tropicamide OD. High‐resolution ultrasound images were obtained at 0, 1, 5, and 10 h post‐treatment to measure ASM changes. IOP and PD were measured OD at 0, 1, 2, 3, 5, 7, and 9 h. Results In untreated normal cats IOP OU decreased throughout the day. In PCG cats IOP OU had wide fluctuations over time. In normal cats IOP response varied in the treated eye but did not change significantly in untreated eyes. IOP significantly increased from baseline in both eyes of all treated PCG cats. Increases in IOP were associated with some ASM changes. Cats with PCG had a significantly smaller angle recess areas, diminished ciliary clefts and decreased iris‐lens contact. ASM changes were not strongly correlated with IOP in all cats. Conclusions The ASM of PCG cats is markedly different from normal cats, and clinically significant increases in IOP OU occur in cats with PCG after tropicamide treatment. The mechanism for this increase remains unclear.     

Evaluation of effectiveness and efficiency of wild bird surveillance for avian influenza

This study aimed to assess which method of wild waterbird surveillance had the greatest probability of detecting highly pathogenic avian influenza (HPAI) H5N1 during a period of surveillance activity, the cost of each method was also considered. Lake Constance is a major wintering centre for migratory waterbirds and in 2006 it was the site of an HPAI H5N1 epidemic in wild birds. Avian influenza surveillance was conducted using harmonised approaches in the three countries around the lake, Austria, Germany and Switzerland, from 2006–2009. The surveillance consisted of testing birds sampled by the following methods: live birds caught in traps, birds killed by hunters, birds caught in fishing nets, dead birds found by the public and catching live Mute Swans (Cygnus olor); sentinel flocks of Mallards (Anas platyrhynchos) were also used. Scenario tree analysis was performed including sensitivity analysis, followed by assessment of cost-effectiveness. Results indicated that if HPAI H5N1 was present at 1% prevalence and assuming HPAI resulted in bird mortality, sampling dead birds found by the public and sentinel surveillance were the most sensitive approaches despite residual uncertainty over some parameters. The uncertainty over the mortality of infected birds was an influential factor. Sampling birds found dead was most cost-effective, but strongly dependent on mortality and awareness of the public. Trapping live birds was least cost-effective. Based on our results, we recommend that future HPAI H5N1 surveillance around Lake Constance should prioritise sentinel surveillance and, if high mortality is expected, the testing of birds found dead.     

Study on activity pattern and incidence of stereotypic behavior in captive tigers

The present study examined daytime behavior patterns of 19 captive tigers (Panthera tigris tigris) housed in Nandankanan Zoological Park, Odisha, India. Behavioral observations of 1254 hours were analyzed for target behaviors using instantaneous sampling and 1-minute sample periods. We found that these captive tigers spent about 23% of the daytime exhibiting stereotypic behavior, that is, pacing, with a biphasic peak at 10:00 to 11:00 am and 16:00 to 17:00 pm. The incidence of stereotypic pacing behavior appears high, warranting further investigation of the cause of this stereotypic behavior and whether an effect of behavioral enrichment is required for a better understanding of welfare implications on the animals.     

Surveillance for highly pathogenic avian influenza in wild birds in the USA

As part of the USA's National Strategy for Pandemic Influenza, an Interagency Strategic Plan for the Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds was developed and implemented. From 1 April 2006 through 31 March 2009, 261 946 samples from wild birds and 101 457 wild bird fecal samples were collected in the USA; no highly pathogenic avian influenza was detected. The United States Department of Agriculture, and state and tribal cooperators accounted for 213 115 (81%) of the wild bird samples collected; 31, 27, 21 and 21% of the samples were collected from the Atlantic, Pacific, Central and Mississippi flyways, respectively. More than 250 species of wild birds in all 50 states were sampled. The majority of wild birds (86%) were dabbling ducks, geese, swans and shorebirds. The apparent prevalence of low pathogenic avian influenza viruses during biological years 2007 and 2008 was 9.7 and 11.0%, respectively. The apparent prevalence of H5 and H7 subtypes across all species sampled were 0.5 and 0.06%, respectively. The pooled fecal samples (n= 101 539) positive for low pathogenic avian influenza were 4.0, 6.7 and 4.7% for biological years 2006, 2007 and 2008, respectively. The highly pathogenic early detection system for wild birds developed and implemented in the USA represents the largest coordinated wildlife disease surveillance system ever conducted. This effort provided evidence that wild birds in the USA were free of highly pathogenic avian influenza virus (given the expected minimum prevalence of 0.001%) at the 99.9% confidence level during the surveillance period.     

Yohimbine antagonizes the anaesthetic effects of ketamine–xylazine in captive Indian wild felids

ObjectiveTo determine the effectiveness of yohimbine as an antagonist of ketamine-xylazine anaesthesia in captive Asiatic lions (Panthera leo persica), tigers (Panthera tigris) and leopards (Panthera pardus).Study designProspective clinical trial.AnimalsFifty-two healthy adult lions, 55 adult leopards and 16 adult male tigers.MethodsCaptive wild felids in Indian zoos were anaesthetized with a combination of ketamine (2.2-2.6 mg kg^?1) and xylazine (1.1-1.3 mg kg^?1) using a dart propelled from a blowpipe. Time to onset of anaesthesia, lateral recumbency and induction time were measured, and physiological variables (respiration, heart rate and rectal temperature) were recorded once after the onset of complete anaesthesia. Anaesthesia was antagonized at various time periods with an intravenous administration of either 0.1 or 0.15 mg kg^?1 yohimbine. Onset of arousal and time to complete anaesthetic recovery were recorded.ResultsA total of 123 immobilizations were conducted between 2000 and 2005. Anaesthetic induction was achieved in 15-25 minutes in all animals. Incidents of sudden recovery or life-threatening effects associated with immobilizations were not observed. Yohimbine effectively antagonized anaesthesia in all animals within 10 minutes without any excitatory behaviour compared to control animals. No adverse reactions/side effects to yohimbine were recorded except that a few leopards exhibited seizure-like signs for a short period immediately after yohimbine administration. The duration of anaesthesia had no significant effect on the recovery time in any of the animals.Conclusion and clinical relevanceYohimbine antagonized the xylazine portion of ketamine-xylazine anaesthesia and thereby hastened recovery from anaesthesia in Asiatic lions, tigers and leopards.     

Australian surveillance for avian influenza viruses in wild birds between July 2005 and June 2007

Objective   To identify and gain an understanding of the influenza viruses circulating in wild birds in Australia.
Design   A total of 16,303 swabs and 3782 blood samples were collected and analysed for avian influenza (AI) viruses from 16,420 wild birds in Australia between July 2005 and June 2007. Anseriformes and Charadriiformes were primarily targeted.
Procedures   Cloacal, oropharyngeal and faecal (environmental) swabs were tested using polymerase chain reaction (PCR) for the AI type A matrix gene. Positive samples underwent virus culture and subtyping. Serum samples were analysed using a blocking enzyme-linked immunosorbent assay for influenza A virus nucleoprotein.
Results   No highly pathogenic AI viruses were identified. However, 164 PCR tests were positive for the AI type A matrix gene, 46 of which were identified to subtype. A total of five viruses were isolated, three of which had a corresponding positive PCR and subtype identification (H3N8, H4N6, H7N6). Low pathogenic AI H5 and/or H7 was present in wild birds in New South Wales, Tasmania, Victoria and Western Australia. Antibodies to influenza A were also detected in 15.0% of the birds sampled.
Conclusions   Although low pathogenic AI virus subtypes are currently circulating in Australia, their prevalence is low (1.0% positive PCR). Surveillance activities for AI in wild birds should be continued to provide further epidemiological information about circulating viruses and to identify any changes in subtype prevalence.     

Comparison of antimicrobial resistant Escherichia coli in wild and captive Japanese serows.

The fecal Escherichia coli isolated from wild Japanese serows living in mountainous areas away from humans and those from captive serows kept in human areas were examined for antimicrobial resistance and the possession of transferable R plasmids. Of 874 E. coli strains isolated from 283 wild serows in 1980-1981, only 11 (1.3%) were resistant to at least one of 6 antimicrobial drugs; ampicillin, streptomycin, tetracycline, chloramphenicol, kanamycin and sulfadimethoxin. Seven (2.5%) individuals were found to carry resistant E. coli. To heighten the isolation frequency of drug-resistant strains, fecal samples of 244 wild serows in 1983-1984 were cultured directly onto drug-supplemented media. Only 12 (4.9%) serows were shown to have drug-resistant E. coli. No transferable R plasmid was detected among a total of 87 resistant strains from wild serows. In contrast, all 33 captive serows except one which was kept only one day after capture, showed resistant E. coli and 20 (60.6%) serows were excreting R plasmid-carrying E. coli. Of 161 drug-resistant strains from captive serows, 50 (31.1%) were found to carry R plasmids. Wild serows seemed to readily change to harbor resistant E. coli almost as soon they were reared in human areas without direct exposure to drugs. These results lead to the conclusion that drug-resistant E. coli can probably be used as microbial indicator for natural environmental pollution.     

一株野鸟源H9N2亚型禽流感病毒的全基因组序列分析及致病性研究

为进一步了解2014年分离自我国南方野鸟粪便中的一株H9N2亚型禽流感病毒(AIV)Wide Bird/Hu N/SC1400/2014(H9N2)(WB/400/14)的生物学特性,本研究对其进行全基因组序列测定、进化分析及SPF鸡、SPF鸭和BALB/c小鼠的感染性试验。序列分析显示:该分离株的HA裂解位点基序为333PAASDR↓GL340,其中不存在多个连续的碱性氨基酸,符合低致病性禽流感病毒(LPAIV)氨基酸序列特征。该分离株不同基因片段来源较复杂,分别与H9、H6、H4、H1、H11、H10、H3等多种亚型的LPAIV同源性较高,呈现明显的多样性。感染性试验显示,WB/400/14不能够在SPF鸡和小鼠体内有效复制,但病毒感染SPF鸭后能够在部分脏器中检测到病毒的存在,并且感染鸭能通够过咽喉和泄殖腔同时向外排毒,而同居感染鸭仅通过泄殖腔向外排毒,表明分离株在SPF鸭群中具有良好的水平传播能力。本研究为AIV的监测和防控提供实验依据。     

野鸟源H5N8禽流感病毒遗传变异分析与致病性评估

本试验在野鸟禽流感病毒紧急疫情检测过程中鉴定并分离到1株H5N8高致病性禽流感病毒,利用病毒全基因组测序、系统发育及关键氨基酸位点分析解析了该野鸟源H5N8禽流感病毒分离株遗传进化情况,通过体外复制动力学试验及小鼠感染试验,评价了该野鸟源H5N8禽流感病毒分离株对哺乳动物致病性。进化分析显示,该病毒株属于Clade 2.3.4.4,可以不经适应直接感染小鼠并在呼吸系统内复制,表现出有限的组织嗜性,对小鼠呈低致病性。其在体内外复制能力较低。结果表明,本试验加深了对野生鸟携带H5N8禽流感病毒的认识和理解、对野鸟源H5N8禽流感病毒生物学特性的评价,为预测野鸟源H5N8禽流感病毒遗传进化趋势及其生物安全风险评估提供借鉴和参考。