1. Investigación

Background: In modern times, horses are utilized not only for labour and transportation purposes but also for recreational activities such as competition and pleasure riding. In these various pursuits, the role of vision plays a crucial role. Electroretinography is the most used test to diagnose diseases of the retinal outer segment. There is a wide variety of devices to perform the electroretinography differing one from each other in the corneal electrode and the light stimulation. The Koijman electrode has been tested in dogs but not in horses. The main purpose of this study was to compare electroretinography parameters from horses sedated with detomidine alone or in combination with butorphanol, during a standardized protocol using the Koijman electrode and RETI-port® system. Seven mares were allocated to the detomidine and detomidine plus butorphanol group in a randomised, controlled, crossover study. Friedman and Willcoxon-signed ranked tests were used to compare the electroretinogram parameters. A Student's t-test was used to compare differences in the number of artefacts to valid values ratio obtained under both sedation protocols. Results: Dark adaptation peaked after 16 min under scotopic conditions in both groups. No significant differences in electroretinogram parameters between groups were observed. During the mixed rod and cone response evaluation under scotopic conditions, all mares made a movement of the head resulting in a high number of artefacts. The detomidine plus butorphanol group showed a non-significant tendency to have fewer artefacts and a longer duration of sedation compared to the detomidine group. Conclusions: Detomidine alone or combined with butorphanol may be suitable to use Koijman electrode and the RETI-port® to perform a standardized long protocol in horses with some adaptations.

Background: Salmonellosis is one of the most important food-borne zoonotic disease affecting both animals and humans. The objective of the present study was to identify gastrointestinal (GI) lactic acid bacteria (LAB) of canineorigin from Salmonella-negative dogs’ faeces able to inhibit monophasic Salmonella Typhimurium previously isolated from dogs’ faeces, in order to be used as a potential probiotic in pet nutrition. Results: Accordingly, 37 LAB were isolated from Salmonella-negative dogs’ faeces and tested against monophasic S. Typhimurium using the spot on lawn method out of which 7 strains showed an inhibition halo higher than 2.5 cm. These 7 strains were also tested with the co-culture method and one showed the greatest inhibition value (p < 0.05). Subsequently, the isolate was identified through 16S rRNA sequencing and sequence homology and designated as Ligilactobacillus salivarius (L. salivarius). LAB from Salmonella-positive dogs were also identified and none was the selected strain. Finally, to identify the mechanism of inhibition of L. salivarius, the supernatant was analyzed, and a dose response effect was observed. Conclusions: It is concluded that the canine-origin L. salivarius, could possess some in vitro functional attributes of a candidate probiotic and could prevent monophasic S. Typhimurium colonization or inhibit its activity if the infection occurs.

West Nile virus (WNV) is an emerging and re-emerging zoonotic flavivirus first identified in and endemic to Africa. The virus is transmitted between birds by biting mosquitoes, with equids and humans being incidental hosts. The majority of infected incidental hosts display no or only mild clinical signs, but a fraction develop encephalitis. The aim of this scoping review was to identify and evaluate primary research on the presence of antibodies to WNV among African equids. Three bibliographic databases and the grey literature were searched. Of 283 articles identified, only 16 satisfied all the inclusion criteria. Data were collated on study design and outcomes. The overall seroprevalence reported ranged from 17.4 to 90.3%, with 1998 (35%) of the 5746 horses, donkeys and mules having screened positive for WNV antibodies. Several articles determined that seroprevalence increased significantly with age. Due to co-circulation of other flaviviruses in Africa, in the majority of studies that screened samples by ELISA, positive results were confirmed using a more specific neutralization test. However, only eight studies tested against other flaviviruses, including Potiskum, Uganda S, Wesselsbron and yellow fever virus in one, Japanese encephalitis and Usutu virus (USUV) in one, tick-borne encephalitis and USUV in one and USUV only in three. Equids are regarded as useful sentinel animals for WNV, but variation in study design poses challenges when trying to determine risk factors for, and trends in, WNV seroprevalence.

The vaginal microbiota plays an important role in the health of dairy cattle, and it could be manipulated for the prevention and treatment of reproduction-related infections. The present study profiles and compares the vaginal microbiota of healthy dairy heifers during the estrous cycle focusing the results in follicular (estrus) and luteal (diestrus) phases using 16S rRNA sequencing of the V3–V4 hypervariable region. Twenty 13–16-months-old virgin dairy heifers from a single farm were included in this study. Vaginal swabs and blood samples were obtained during estrus (6–8 h before artificial insemination) and diestrus (14 days after insemination). Estrus was evaluated by an activity monitoring system and confirmed with plasma progesterone immunoassay. Results showed that the taxonomic composition of the vaginal microbiota was different during the follicular and luteal phases. At the phylum level, the most abundant bacterial phyla were Tenericutes, Firmicutes, and Bacteroidetes which comprised more than 75%of the vaginal microbiota composition. The next more abundant phyla, in order of decreasing abundance, were Proteobacteria, Actinobacteria, Fusobacteria, Epsilonbacteraeota, and Patescibacteria. Together with Tenericutes, Firmicutes, and Bacteroidetes represented more than 96% of the bacterial composition. Ureaplasma, Histophilus, f_Corynebacteriaceae, Porphyromonas, Mycoplasma, Ruminococcaceae UCG-005, were the most abundant genera or families. The results also showed that the vaginal microbiota of dairy heifers was non-lactobacillus dominant. The genus Lactobacillus was always found at a low relative abundance during the estrous cycle being more abundant in the follicular than in the luteal phase. Despite more research is needed to explore the potential use of native vaginal microbiota members as probiotics in dairy heifers, this study represents an important step forward. Understanding how the microbiota behaves in healthy heifers will help to identify vaginal dysbiosis related to disease.

Background: Comparisons between smartphone ECG (SpECG) recordings obtained from the right and left sides of the thorax have not been reported in animals. Objectives: To evaluate the screening potential of a SpECG obtained from both sides of the thorax and to compare the degree of agreement between the SpECG and a reference ECG (rECG) for measurement of the duration of baseline electrical deflections recorded over both sides of the thorax. Animals: Fifty horses admitted to the equine hospital, university-owned horses, and horses from an endurance riding facility. Methods: Prospective observational study. Simultaneous rECG and SpECG tracings were recorded on both sides of the thorax and evaluated by 2 experienced observers for interpretability, presence and classification of arrhythmias, and duration of deflections of the electrical baseline. Results: Fifteen (15/50) horses had spontaneous arrhythmias. Excellent agreement was found between the 2 devices (κ = 0.91; P < .001; 95% confidence interval [CI] 0.79-1.03) for the detection of arrhythmias. Significantly more P waves were of diagnostic quality from the right side (20 versus 5, P = .001) and significantly more QRS and QT intervals were of diagnostic quality from the left side (66 versus 38 and 62 versus 34, respectively, P < .001). Substantial agreement for the duration of deflections between devices only was observed for the QRS interval (SpECG left). Conclusions and Clinical Importance: It is important to obtain SpECG tracings from both sides of the thorax in horses. The SpECG is a useful stall-sidearrhythmiascreening tool for some common arrhythmias in horses.

Sheep estrous synchronization is mainly based on progestagen-impregnated sponges which could cause vaginitis. Several species of Lactobacillus used as probiotics are commonly used in the treatment or prevention of urogenital infections in humans. However, no studies have been performed to analyze the potential use of probiotics to prevent urogenital infections in sheep. A randomized controlled clinical trial was conducted with 21 one-year-old ewes to develop a model of probiotic infusion in vaginal sponges in order to study their influence in ewe’s vaginal microbiota, general health status, fertility and prolificity. Synchronization of estrus was based on intravaginal sponges for 14 days. Bacterial communities (Enterobacteriaceae and lactic acid bacteria) were highly fluctuating over time and between animals. The safety of probiotic infusion (mix of Lactobacillus spp. 60% L. crispatus, 20% L. brevis and 20% L. gasseri) in the vagina of healthy ewes was firstly confirmed. Neutrophils were observed in 80% (8/10) of the control ewes compared to 36% (4/11) of the ewes in the probiotic group 2 days after sponge removal (p = 0.056). Fertility in the control and probiotic groups was 60% (6/10) and 91% (10/11), respectively p = 0.097. These results suggest that Lactobacillus spp. infusion in the ewe’s vagina does not affect general health status or fertility.

Lactic acid bacteria (LAB) dominate human vaginal microbiota and inhibit pathogen proliferation. In other mammals, LAB do not dominate vaginal microbiota, however shifts of dominant microorganisms occur during ovarian cycle. The study objectives were to characterize equine vaginal microbiota in mares by culture-dependent and independent methods and to describe its variation in estrus and diestrus. Vaginal swabs from 8 healthy adult Arabian mares were obtained in estrus and diestrus. For culture-dependent processing, bacteria were isolated on Columbia blood agar (BA) and Man Rogosa Sharpe (MRS) agar. LAB comprised only 2% of total bacterial isolates and were not related to ovarian phases. For culture-independent processing, V3/V4 variable regions of the 16S ribosomal RNA gene were amplified and sequenced using Illumina Miseq. The diversity and composition of the vaginal microbiota did not change during the estrous cycle. Core equine vaginal microbiome consisted of Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria at the phylum level. At the genus level it was defined by Porphyromonas, Campylobacter, Arcanobacterium, Corynebacterium, Streptococcus, Fusobacterium, uncultured Kiritimatiaellae and Akkermansia. Lactobacillus comprised only 0.18% of the taxonomic composition in estrus and 0.37% in diestrus. No di erences in the relative abundance of the most abundant phylum or genera were observed between estrus and diestrus samples.

Members of several different virus families cause equine viral encephalitis, the majority of which are arthropod-borne viruses (arboviruses) with zoonotic potential. The clinical signs caused are rarely pathognomonic; therefore, a clinical diagnosis is usually presumptive according to the geographical region. However, recent decades have seen expansion of the geographical range and emergence in new regions of numerous viral diseases. In this context, this review presents an overview of the prevalence and distribution of the main viral causes of equine encephalitis and discusses their impact and potential approaches to limit their spread.