Isolated orbital mucoceles in the absence of obstructive sinus disease.

Orbital surgeons are quite familiar with the diagnosis and management of paranasal sinus mucoceles due their frequent involvement of the orbit. These benign masses form and expand following sinus outflow obstruction secondary to various causes including trauma, inflammation and malignancy, amongst others. The authors present two cases of isolated orbital mucoceles without associated sinus outflow obstruction. There were notably no connections between the paranasal sinuses and the lesions. The mucoceles were diagnosed following orbitotomies and excisional biopsies with confirmatory histopathology. These rare orbital lesions should be considered when evaluating cystic orbital lesions, and the orbital surgeon should be familiar with the proposed pathophysiology and treatment recommendations.

Further evaluation and validation of a commercially available competitive ELISA (cELISA) for the detection of antibodies specific to equine arteritis virus (EAV).

The purpose of this study was to further evaluate and validate two commercially available equine arteritis virus (EAV) competitive ELISAs (original and enhanced cELISAs) using archived equine sera from experimentally inoculated animals and field sera submitted for laboratory diagnosis. First, the original and subsequently enhanced cELISAs were compared with the virus neutralisation test (VNT) using a panel of archived serum samples from experimentally inoculated animals. Then, the enhanced cELISA was compared with the VNT using a large panel of archived serum samples. The total number of equine sera tested was 3255, which included sera against 25 different EAV strains. The study confirmed that the enhanced cELISA was more sensitive than the original cELISA. Based on testing sera from experimentally inoculated animals and field sera, the enhanced cELISA had an estimated sensitivity (98.9 percent and 99.6 percent, respectively) and specificity (98.3 percent and 98.7 percent, respectively). The currently marketed enhanced VMRD EAV antibody cELISA test kit (VMRD Inc., Pullman, Washington, USA) has high sensitivity and specificity relative to the VNT. Based on the findings of this study, the authors would propose that the enhanced cELISA should be considered as an alternative approved method to the VNT for the detection of antibodies to EAV.

Equine disease events resulting from international horse movements: Systematic review and lessons learned.

REASONS FOR PERFORMING STUDY: An analysis of the factors leading to equine disease events was used to support the development of international recommendations for mitigating the risk of disease dissemination through sport horse movements (high health, high performance - 'HHP' horses). OBJECTIVES: A review was undertaken to identify the factors resulting in equine disease events following international movement of horses to draw lessons in support of the development of international recommendations for the safe movements of a specific subpopulation of horses: the HHP sport horses. STUDY DESIGN: Systematic review carried out in accordance with the PRISMA statement. METHODS: The review covered disease events that occurred from 1995 to 2014, identified from the databases of the World Organisation for Animal Health (OIE) and international surveillance reports. RESULTS: Overall, 54 disease events were identified, of which 7 were contained in post arrival quarantine and the others resulted in the introduction of pathogens into importing countries. For 81% of the introductions, the OIE recommendations applicable to the diseases involved had not been complied with. Subclinical infections are a challenge for international trade: 88% of the regulated movements that resulted in introductions involved infected horses that showed no clinical signs at the time of import. Biosecurity and management practices in resident equine populations were identified as important mitigating factors in preventing disease spread to the local horse population. CONCLUSIONS: The global increase in international horse movements, if not appropriately regulated and supervised by competent veterinary authorities and respective equine industry partners, could potentially lead to increased global spread of infectious equine diseases. Appropriate mitigation measures and compliance with OIE import recommendations for specific diseases can significantly reduce this risk. The recommendations proposed under the HHP approach take into account the mitigation measures identified by this review as important factors in preventing pathogen introduction and spread.

Franciscus Cornelis Donders (1818-1889).

Franciscus Cornelis Donders was educated at Duizel and Boxmeer before entering the Military Medical School and the medical faculty at Utrecht University in 1835. In 1840, he received his MD from Leiden and spent 2 years in practice at Vlissingen before returning to Utrecht, where he was appointed as an extraordinary professor to lecture on forensic medicine, anthropology, general biology and ophthalmology. Refraction by the eye is complex, since the ray of light passes through many changes of refractive index in its path, and Donders simplified the account of the process by establishing an equivalent refractive system: the reduced eye. When Donders opened an Eye Hospital in 1858, he devoted himself to clinical ophthalmology, making fundamental advances in providing spectacles to correct errors of refraction-which he separated from errors of accommodation. In 1862, Donders was promoted as an ordinary professor at Utrecht and he handed over the greater part of his practice to his pupil Hermann Snellen. From narrow specialisation, Donders was freed to return to the broader physiology; subatmospheric pressure in the pleura was for a while referred to as 'Donders' pressure'; he also devised a method of measuring the mental reaction time taken in making discrimination, rather than the simple reaction time in which no choice is involved. He was widely honoured, presiding at international congresses, and elected as a foreign member of the Royal Society. He died suddenly on 14 March 1889, but his work lives on.

'High-health, high-performance' horses: risk mitigation strategies for OIE-listed diseases.

The 'high-health, high-performance' (HHP) horse concept has been developed by the World Organisation for Animal Health (OIE) together with the F6ddration Equestre Internationale and the International Federation of Horseracing Authorities. This concept is outlined in the OIE Terrestrial Animal Health Code (Chapter 4.16). It aims to address impediments to the international movement of competition horses through a harmonised, practically feasible, globally applicable framework based on simplified certification requirements for the temporary importation of HHP horses and for their return to their country of usual residence. Based on the principle of compartmentalisation, the high health status of these horses would be established by the application, at all times, of stringent health management practices and biosecurity measures to create and maintain a functional separation between horses within the defined compartment and all other equids. These provisions are intended to mitigate the risk of disease spread for most OIE-listed diseases. For six OIE-listed diseases (African horse sickness, equine influenza, equine infectious anaemia, equine piroplasmosis, glanders and Venezuelan equine encephalomyelitis), the OIE recommends disease-specific mitigation measures, which have been included in a model HHP Veterinary Certificate, to provide additional guarantees to mitigate the risk of disease spread. This article presents the HH P disease risk mitigation strategy. It demonstrates how continuous observance of the HHP biosecurity measures and health management practices provides a scientific rationale for limiting the list of diseases for which HHP horses should be screened with respect to their temporary importation for competition purposes.

Single-layer centrifugation reduces equine arteritis virus titre in the semen of shedding stallions.

Several countries have adopted strategies for preventing and/or controlling equine viral arteritis based on vaccination and restricting the breeding activities of carrier stallions. However, in some cases, carrier stallions are only identified after they have transmitted virus to a mare. Therefore, a mechanism for separating virus from spermatozoa in the semen of carrier stallions would facilitate control measures for preventing disease transmission. In this study, the use of several modifications of single-layer centrifugation (SLC, SLC with an inner tube and double SLC) through Androcoll-E, a species-specific colloid were evaluated for their ability to separate spermatozoa from virus in ejaculates from carrier stallions. The three types of SLC significantly reduced the virus titre in fresh semen at 0 h and in stored semen at 24 h (p < 0.001) but did not completely eliminate the virus. Sperm motility parameters such as total motility and progressive motility were significantly increased after colloid centrifugation, whereas curvilinear velocity and amplitude of lateral head deviation were decreased, and the remainder (straight line velocity, average path velocity, straightness, linearity, wobble and beat cross-frequency) were not significantly affected by the processing. Although virus titres were reduced in the SLC samples, significant levels of infectivity still remained, especially in stallions shedding large amounts of virus. It remains to be determined whether SLC-processed sperm samples from stallions shedding low virus titres retain sufficient equine arteritis virus to cause infection in mares through artificial insemination.

Allvar Gullstrand and the slit lamp 1911.

The Swedish ophthalmologist and self-taught mathematician Allvar Gullstrand (1862-1930) invented the slit lamp to illuminate the anterior of the eye. With its rectangular beam of very bright light, he studied the structure of the cornea and the function of the lens. His dioptric investigations showed that, as well as the extracapsular mechanism described by Helmholtz, changes in the substance of the lens, that he termed intracapsular, also contribute to accommodation. However, his invention has been appropriated by clinical ophthalmologists and is now routinely used in examination of the eye.

Evaluation of mass spectrometric methods for detection of the anti-protozoal drug imidocarb.

Imidocarb [N,N'-bis[3-(4,5-dihydro-1H-imidazol-2-yl)phenyl]urea, C(19)H(20)N(6)O(1), m.w. 348.41] is a symmetrical carbanilide derivative used to treat disease caused by protozoans of the Babesia genus. Imidocarb, however, is also considered capable of suppressing Babesia-specific immune responses, allowing Babesia-positive horses to pass a complement fixation test (CFT) without eliminating the infection. This scenario could enable Babesia-infected horses to pass CFT-based importation tests. It is imperative to unequivocally identify and quantify equine tissue residues of imidocarb by mass spectrometry to address this issue. As a pretext to development of sensitive tissue assays, we have investigated possibilities of mass spectrometric (MS) detection of imidocarb. Our analyses disclosed that an unequivocal mass spectral analysis of imidocarb is challenging because of its rapid fragmentation under standard gas chromatography (GC)-MS conditions. In contrast, solution chemistry of imidocarb is more stable but involves distribution into mono- and dicationic species, m/z 349 and 175, respectively, in acid owing to the compound's inherent symmetrical nature. Dicationic imidocarb was the preferred complex as viewed by either direct infusion-electrospray-MS or by liquid chromatography (LC)-MS. Dicationic imidocarb multiple reaction monitoring (MRM: m/z 175 → 162, 145, and 188) therefore offer the greatest opportunities for sensitive detection and LC-MS is more likely than GC-MS to yield a useful quantitative forensic analytical method for detecting imidocarb in horses.

Infection of embryos following insemination of donor mares with equine arteritis virus infective semen.

The objective was to evaluate the potential risks associated with embryo transfer from mares bred with equine arteritis virus (EAV) infective semen. Twenty-six mares were embryo donors, whereas 18 unvaccinated and EAV antibody seronegative mares were embryo recipients. Of the 26 donor mares, 15 were unvaccinated and seronegative for antibodies to EAV and 11 were vaccinated for the first time with a commercially available modified live virus vaccine against EVA before breeding and subsequent embryo transfer. All donor mares were bred with EAV-infective semen from a stallion persistently infected with the virus. Twenty-four embryos were recovered 7 d post-ovulation; all were subjected in sequential order to five washes in embryo flush medium, two trypsin treatments, and five additional washes in embryo flush medium (prior to transfer). Twelve and seven embryos (Grades 1 or 2) were transferred from the non-vaccinated and vaccinated donors, respectively, and pregnancy was established in 3 of 12 and 2 of 7. Perhaps trypsin reduced embryo viability and pregnancy rate. The uterine flush fluid of 11 mares (9 of 15 and 2 of 11 from non-vaccinated and vaccinated donor groups, respectively) was positive for EAV by VI (confirmed by real-time RT-PCR); the wash fluid from the embryos of nine of these mares was negative following 10 washes and two trypsin treatments. However, the embryo wash fluid from two mares was still positive for EAV after all 10 washes and the two trypsin treatments, and one embryo was positive for EAV. Two of 18 recipient mares had seroconverted to EAV 28 d after embryo transfer. Virus was not detected in any fetal tissues or fluids harvested after pregnancies were terminated (60 d). In conclusion, we inferred that the washing protocol of 10 washes and two trypsin treatments did not eliminate EAV from all embryos; due to limitations in experimental design, this requires confirmation. Furthermore, there may be a risk of EAV transmission associated with in vivo embryo transfer from a donor mare inseminated with EAV infective semen.

Horse species symposium: contagious equine metritis: an insidious threat to the horse breeding industry in the United States.

Contagious equine metritis (CEM) has given rise to international concern since it was first recognized as a novel venereal disease of equids in 1977 and the etiologic agent was identified as a previously undescribed bacterium, Taylorella equigenitalis. Horse industry concerns over CEM centered on the ease with which this bacterium could be disseminated, the significance of T. equigenitalis as a cause of short-term infertility in the mare, and the existence of the carrier state in the stallion and the mare. The first known outbreak of CEM in the United States was in Kentucky in 1978. The economic impact on the Thoroughbred industry in the state was substantial. Before 2008, additional small-scale outbreaks occurred in Missouri in 1979, Kentucky in 1982, and Wisconsin in 2006, nearly all attributed to the importation of carrier animals. On each occasion, appropriate measures were taken to eliminate the infection, resulting in the United States regaining its CEM-free status. With the exception of the 1978 occurrence in Kentucky, none of the subsequent outbreaks significantly affected the horse industry. That changed dramatically in 2008, however, after the discovery of a Quarter horse stallion in Kentucky that cultured positive. Subsequent investigations turned up 23 carrier stallions and 5 carrier mares belonging to 11 breeds and located in 8 states. Shipment of infective semen and indirect venereal contact in stallion collection centers through the use of contaminated fomites were major factors in the spread of T. equigenitalis. Trace-back investigations of some 1,005 exposed and carrier stallions and mares in 48 states have failed to identify the origin of this latest CEM event. Neither clinical evidence of CEM nor decreased pregnancy rates were reportedly a feature in infected or exposed mares. In light of these findings, there was some question of whether or not the considerable expense incurred in investigating the latest CEM occurrence was warranted. Regaining CEM-free status for the United States will present considerable challenges.

Initial occurrence of Taylorella asinigenitalis and its detection in nurse mares, a stallion and donkeys in Kentucky.

In 1998, a newly identified bacterium Taylorella asinigenitalis was isolated from the external genitalia and reproductive tracts of nurse mares, a stallion and donkey jacks in Kentucky. An extensive regulatory effort was implemented to contain the outbreak including the tracing and testing of 232 horses and donkeys on 58 premises. T. asinigenitalis was isolated from the reproductive tract of 10 adult equids, including two donkey jacks, one Paint Quarter-horse stallion and seven draft-type breeding mares. None of the infected horses had clinical signs of reproductive tract disease. The odds of being culture positive were 20 times greater for a mare bred to a donkey than for a mare bred to a stallion. Approximately 18% of mares bred to either a carrier stallion or donkey jack were confirmed culture positive. Seventy-one percent of infected mares required more than one course of treatment to clear the organism from their reproductive tracts and one mare harbored the organism for more than 300 days.

Douglas Argyll Robertson (1837-1909) and his pupil.

Douglas Argyll Robertson's (1837-1909) experimental work with physostigmine in 1863 sharpened his knowledge of the innervation of the internal muscles of the eye. So he was ideally prepared in 1869 to analyse the conundrum when he saw patients with spinal cord disease who had lost the response to light even though accommodation to near objects was normal. By translating his knowledge of basic science to a clinical problem he drew attention to this phenomenon, known subsequently as the Argyll Robertson pupil that came to be considered pathognomonic of tabes dorsalis, general paresis and neurovascular syphilis.

Equine viral arteritis: current status and prevention.

Recently, there has been increased interest in equine viral arteritis (EVA) among veterinarians and horse owners. Outbreaks of the disease were identified initially in New Mexico, USA in 2006, and in the Normandy region of France in the summer of 2007. Both occurrences were associated with AI of cool-shipped semen. Each was linked to respiratory illness, neonatal death, abortion, development of carrier stallions, and cancellation of equestrian events. In light of the increased interest, this paper will present a brief case history, followed by a review addressing common concerns regarding EVA, current status, and control and prevention strategies, including vaccination, and recommended bio-security measures.

Equine travellers to the Olympic Games in Hong Kong 2008: a review of worldwide challenges to equine health, with particular reference to vector-borne diseases.

The past 10-20 years have seen exponential growth in the volume of trade in horses and equine germplasm; and the extent of global horse movements has increased significantly in the last 4 years. In preparing for the transport of elite Olympic horses to Hong Kong in 2008, it will be very important to be as fully informed as possible of the disease situation in both the exporting and importing country, import and re-entry requirements, as well as having a vaccination strategy to protect against particular diseases. In this context the review describes the equine vector-borne disease situation in Europe, Asia, Africa and South America and provides estimates of the number of horse movements between these countries, as well as information on import requirements and vaccination strategies.

Genetic variation and phylogenetic analysis of 22 French isolates of equine arteritis virus.

Genetic variation and phylogenetic relationships among 22 French isolates of equine arteritis virus (EAV) obtained over four breeding seasons (2001-2004) were determined by sequencing open reading frames (ORFs) 2a-7. The ORFs 2a-7 of 22 isolates differed from the prototype virulent Bucyrus strain of EAV by between 14 (99.5% identity) and 328 (88.7% identity) nucleotides, and differed from each other by between 0 (100% identity) and 346 (88.1% identity) nucleotides, confirming genetic diversity among EAV strains circulating in France. Phylogenetic analysis based on the partial ORF5 sequences (nucleotides 11296-11813) of 22 French isolates and 216 additional EAV strains available in GenBank clustered the global isolates of EAV into two distinct groups: North American and European. The latter could be further divided into two large subgroups: European subgroup 1 (EU-1) and European subgroup 2 (EU-2). Phylogenetic analysis based on 100 EAV ORF3 sequences yielded similar results. Of the 22 French EAV isolates, the 11 isolates obtained before January 28, 2003 clustered with either the EU-1 (9 isolates) or EU-2 (2 isolates) subgroup. In contrast, by the criteria used in this study, the 11 isolates obtained after January 30, 2003 belong to the North American group, strongly suggesting that these strains were recently introduced into France.

Lateral transmission of equine arteritis virus among Lipizzaner stallions in South Africa.

REASONS FOR PERFORMING STUDY: A serological study conducted in 1995 revealed that 7 stallions at the Lipizzaner Centre, Gauteng, South Africa, were seropositive for antibody to equine arteritis virus (EAV). A Lipizzaner stallion imported into South Africa from Yugoslavia in 1981 had previously (1988) been confirmed to be an EAV carrier. Despite being placed under life-long breeding quarantine, EAV had been transmitted between stallions at the Lipizzaner Centre. OBJECTIVES: To investigate the phylogenetic relationships between the strain of EAV shed in the semen of the original carrier stallion and strains recovered from the semen of 5 other stallions; and to investigate the means whereby lateral transmission of EAV occurred among 7 in-contact, nonbreeding stallions at the Centre. METHODS: EAV was isolated from semen collected from the seropositive stallions using RK-13 cells. Viral RNA was reverse transcribed and amplified by polymerase chain reaction using ORF 5-specific primers, subjected to sequence and phylogenetic analysis. RESULTS: Phylogenetic analysis of strains of EAV recovered from the semen of 6 persistently infected stallions confirmed that all viruses were closely related and probably derived from a common ancestor, i.e. the stallion imported from Yugoslavia. Lateral transmission subsequently occurred among 7 in-contact, nonbreeding stallions at the Centre. It is speculated that these stallions may have been exposed to virus from bedding or fomites contaminated with semen. CONCLUSIONS: These data confirm that lateral transmission of EAV can occur from shedding stallions to susceptible, in-contact horses, including other stallions, which may become persistently infected with the virus. POTENTIAL RELEVANCE: The findings are consistent with lateral spread of a single, unique strain of EAV among a group; and suggest that transmission of EAV may be initiated by infection of one or more stallions with virus on bedding or other fomites contaminated with EAV- infected semen.

Prevalência de anticorpos antivírus da arterite dos eqüinos em cavalos criados no Estado de Säo Paulo / Prevalence of equine arteritis virus specific antibodies in horses of Säo Paulo State, Brazil

Utilizou-se a prova de soroneutralização em microplacas para detecção de anticorpos antivírus da arterite dos eqüinos em 659 amostras de soro sangüíneo de animais criados no Estado de São Paulo. A prevalência de anticorpos na população estudada foi igual a 18,2 por cento. A raça Mangalarga foi a que apresentou maior taxa de prevalência, 33,3 por cento. Animais na faixa etária de 6 a 24 meses de idade apresentaram a maior taxa de prevalência, 30,4 por cento, e as fêmeas apresentaram prevalência de 22, 9 por cento, mais alta do que nos machos

With the purpose of studying the prevalence of equine viral arteritis in horses raised in São Paulo State, Brazil, by the standard microtiter serum neutralization test, 659 serum samples were investigated. The prevalence of antibodies in the horse population was 18.2 per cent, which was significantly higher in Mangalarga horses (33.3 per cent) than in any other breed (Thoroughbred, Arab, Quarter Horse, mixed breeds and others). The distribuition of horses by age showed that horses between 6 to 24 months of age (30.4 per cent) had a higher prevalence (30.4 per cent) rate than others. The female horses prevalence rate of 22.9 per cent was significantly higher than in male horses.