Search Results (131)

To date, five herpesviruses have been identified in Leporidae (LeHV-1, LeHV-2, LeHV-3, LeHV-4, and LeHV-5). Two of these have been shown to infect the European rabbit (Oryctolagus cuniculus), causing either asymptomatic infection (LeHV-2, a gammaherpesvirus) or virulent disease (LeHV-4, an alphaherpesvirus). Unfortunately, apart from LeHV-4, for which complete genome sequences are available, molecular data on leporid herpesviruses are extremely limited, with no sequences available in public databases for LeHV-1 and LeHV-3, and only a few short sequences for LeHV-2 and LeHV-5. In this study, we investigated the presence of herpesviruses in biological samples from wild rabbits (n = 34) found dead in the field during 2024. A pan-herpesvirus nested PCR directed to the herpesviral DNA polymerase gene was used for screening. Positive samples (n = 14, 41.17%) were further investigated by sequencing analysis of a longer region of the DNA polymerase gene, as well as the glycoprotein B gene and the terminase gene. Blastn analysis of the amplicons revealed the highest similarity to gammaherpesvirus. Phylogenetic analyses based on glycoprotein B, DNA polymerase, and concatenated amino acid sequences consistently placed the newly identified LeHV-6 in close proximity to LeHV-5. Both viruses form a well-supported clade within the Gammaherpesvirinae, clustering with rodent-associated herpesviruses, such as Murine herpesvirus, MuHV-4, and A. sylvaticus rhadinovirus 1. Considering the species susceptibility and the nucleotide similarities with the five previously described leporid herpesviruses, we conclude that a new rabbit gammaherpesvirus has been identified, which we propose to name LeHV-6. Full article

Encephalitozoon cuniculi is a microsporidian widely spread in rabbits (Oryctolagus cuniculus) and other species, including humans, causative of neurological disorders or remaining in a latent state in the host organism. The aim of this study was to estimate the prevalence of E. cuniculi in rabbits located in the North-Western region of Romania, and to run a comparative diagnosis for E. cuniculi by multiple methods. A total of 381 rabbits were included, originating from households, family farms and wildlife, which were subjected to serological and/or molecular genetics diagnostic methods for E. cuniculi identification. Seropositivity of 43.02% (151/351) was obtained by ELISA, together with a 45.45% (110/242) prevalence from urine, feces and organs by nested PCR. Additionally, a prevalence of 48.39% (15/31) was identified by a comparative real-time PCR (qPCR). The urinary bladder is firstly reported for molecular E. cuniculi diagnosis, with a positivity of 30.56% (11/36) by nested PCR. Despite the disagreement between the diagnostic methods, the present results highlight the level of pathogen dissemination among rabbits in North-Western Romania that represents a risk for not only rabbits and other animals, but also for the general public by its zoonotic character. Full article

This study evaluated the effect of freezing for up to 120 days on the physicochemical and technological properties of hamburgers made from Botucatu rabbit does slaughtered at 3, 12, and 24 months of age. The parameters were evaluated as follows: surface color (L*, a*, b*), pH using an insertion pH meter, cooking loss using a grill, storage loss based on weight differences, shear force in cooked samples using a texture analyzer, shrinkage percentage, chemical composition (moisture, protein, lipids, and ash), and lipid oxidation, determined by measuring the concentration of malondialdehyde in the burgers at different storage intervals (0, 60, and 120 days) under freezing conditions (−18 °C). The results indicated that increased storage time and animal age reduced tenderness and increased lipid content (p < 0.05). Burgers made from younger does showed higher levels of lipid oxidation. Age also influenced color (greater redness and lower lightness in older animals) and chemical composition, with older does producing burgers with higher protein and lower moisture and mineral content. However, all samples remained within the limits established by Brazilian legislation. This study recommends using meat from does of different ages for hamburger production, as all variations met the required legal standards. Full article

(1) Background: We combined physiological and morphological data of the European rabbit (Oryctolagus cuniculus) to provide insights into the question of how urbanization affects the health of urban wildlife populations. (2) Methods: We dissected 39 urban and 34 rural wild rabbits in order to compare organ weights, as well as stomach contents. Furthermore, we collected blood and fecal samples. (3) Results: Rural rabbits had a significantly longer body and a higher body weight as well as more fat tissue around their kidneys compared to urban rabbits. In contrast, the stomach, the intestines, the liver, the lung, and the brain of urban rabbits were significantly heavier. The amount of hematocrit, hemoglobin, and the mean corpuscular volume was significantly higher in urban rabbits. The caloric energy content of the stomach was comparable between rural and urban rabbits and was merely influenced by the season being higher in autumn. Rural rabbits had an overall higher mean parasite index compared to urban rabbits. (4) Conclusions: The results of our study allow for a deeper understanding of how density-dependent (e.g., transmission of diseases) and density-independent factors (e.g., food quality) influence the health status and life history traits of urban wildlife populations compared to their rural counterparts. Full article

This study evaluated the effect of two levels of extruded linseed (EL) in the diet on growth performance, carcass yield, and meat quality of growing rabbits. Sixty-nine New Zealand White male rabbits (Oryctolagus cuniculus) were assigned after weaning to three dietary groups: control (C), 2.5% EL (L2.5%), and 5% EL (L5%). At the end of the fattening period (from 37 to 93 days of age), rabbits were slaughtered. EL supplementation significantly reduced average daily weight gain (ADG) in the L5% group (p < 0.05), while other performance parameters were not significantly affected. Meat from the L5% group exhibited a higher fat content (p < 0.001) and lower water-holding capacity (p < 0.05) compared to the others. The fatty acid profile showed a significant increase in n-3 polyunsaturated fatty acids (PUFAs) and a decrease in n-6 PUFA (p < 0.05), resulting in a markedly reduced n-6/n-3 ratio (p < 0.001) in supplemented groups. EL supplementation also enhanced long-chain n-3 PUFA levels, particularly docosapentaenoic acid (DPA). Although lipid oxidation was slightly increased (p < 0.05), sensory attributes remained unaffected. These findings support EL supplementation as a nutritional strategy to increase the n-3 fatty acids in rabbit meat without compromising physical and sensory quality. Full article

Rabbit hemorrhagic disease virus (RHDV) is a very virulent virus of the genus Lagovirus causing severe and fatal hepatitis in the European rabbit (Oryctolagus cuniculus). RHDV has two distinct genotypes: GI.1 (RHDV) and GI.2 (RHDV2). The first RHDV2/GI.2 strain was identified as a recombinant virus between a non-pathogenic (GI.3P) and a pathogenic (GI.2) lagovirus, and the recombination is thought to have been a key mechanism in the emergence and evolution of RHDV2. Here, a new variant of RHDV2 was identified affecting domestic rabbits on Chinese farms, with a mortality rate of 70–80%. Phylogenetic analysis indicated that the nonstructural portion of this newly identified strain’s genome clustered with the GI.1a variants. In contrast, the capsid gene shared the highest nucleotide identity of 97.9% with the North American GI.2 strains, suggesting a possible introduction in China of North American strains and recombination with the GI.1a strains circulating in China. We have produced a recombinant vaccine using the first Chinese GI.2 strain, SC2020/0401, by cloning the vp60 gene into a baculovirus expression vector. Virus-like particles (VLPs) were then produced in Sf9 insect cells, and a challenge study was performed. Rabbits immunized with the VLP vaccine survived 7 d after being challenged with the new virus. The results indicate that commercial vaccines are urgently required in China to control the circulation of RHDV2 variants. Full article

Clostridioides difficile is an anaerobic bacterium that causes disease in both animals and humans. Despite the known significance of this agent, there are no commercial vaccines available for humans, and only one immunogen is marketed for swine. However, no studies have evaluated this vaccine. Background/Objectives: Therefore, the aim of this study was to assess the potency of the first commercial vaccine for C. difficile infection in piglets and to compare the humoral response in rabbits and sows. Methods: Pregnant sows were divided into two groups: a vaccinated group (n = 12), receiving two doses before farrowing, according to the manufacturer’s recommendation, and an unvaccinated control group (n = 6). Blood samples were taken from sows and also from piglets up to two days after birth. In addition, two groups of New Zealand rabbits (Oryctolagus cuniculus) received either a half-dose (G1) or a full-dose (G2) of the vaccine, with a control group receiving sterile saline (0.85%). Rabbits were vaccinated twice, 21 days apart, with blood samples collected before each dose and 14 days after the final dose. A serum neutralization assay in Vero cells was performed to evaluate the titers of neutralizing antibodies. Results: The vaccine demonstrated immunogenicity by stimulating the production of neutralizing antibodies in both rabbits and sows. Additionally, these antibodies were passively transferred to piglets through colostrum, reaching levels comparable to those found in sows. Furthermore, vaccinated rabbits developed antibody titers that do not significantly differ from those obtained in sows and piglets. Conclusions: The tested vaccine can induce a humoral immune response against C. difficile A/B toxins in sows and these antibodies are passively transferred to neonatal piglets through colostrum. Also, the vaccination of rabbits might be a useful alternative for evaluating the potency of vaccines against C. difficile. Full article

A soft tissue-filled external ear canal, sometimes also referred to as otitis externa in the veterinary literature, is a prevalent disease in pet rabbits, especially in lop-eared pet rabbits. The authors describe the clinical findings, diagnostic workup, therapy, and outcome of pet rabbits treated surgically for a lateral ear canal ablation (LECA). For the time period between 2015 and 2023, the medical records of two veterinary clinics were evaluated retrospectively. A total of 25 pet rabbits, diagnosed via computed tomography (CT) scans with a soft tissue-filled external ear canal and (if present) middle ear, were identified. All the pet rabbits were evaluated as lop-eared pet rabbits and all were treated surgically using the same surgical technique, LECA. In accordance with Richardson et al., we categorized the different ear filling levels by using the grading system that was established in 2019. The mean follow-up period was 19 days, and in one case complete wound healing was not reached within 131 days after surgery. A total of 7/25 of the pet rabbits were evaluated with wound healing issues. Of the cases, 18/25 did not develop any recurrent ear diseases. Loss to follow-up was observed in 5/25 of the cases and recurrent ear diseases were identified in 2/25 of the pet rabbits. Progression of the ear disease was detected in four cases. CT post-operative images were acquired for 14/25 of the pet rabbits. Based on this study, LECA can be considered a safe surgical method to treat soft tissue-filled external ear canals, especially in lop-eared pet rabbits. Nonetheless, thorough post-surgical management including wound control is critical for therapy success. Full article

Coccidiosis caused by Eimeria spp. is a parasitic disease with high morbidity that affects various animal species, including rabbits. In rabbits, eleven Eimeria species have been primarily identified through microscopic examination of oocysts; however, this technique has certain limitations that make it challenging to differentiate between Eimeria species. The main objective of this study was to morphologically identify Eimeria species infecting rabbits in Romania, as well as to confirm these identifications using molecular biology techniques, specifically through the ITS-1 rRNA gene. A total of 236 samples were collected from different regions of Romania, of which 77.56% (183/236) tested positive for at least one Eimeria species. The samples were collected from rabbits raised in individual household settings, under various management systems—both in individual cages and in common ground-based enclosures. The areas of origin were chosen randomly, without applying restrictive criteria, specifically to ensure broad representativeness of the farming conditions encountered in practice, regardless of the production system or geographic specificity. The microscopic examination of morphological characteristics identified ten Eimeria species, whereas PCR results confirmed the presence of four species. It was not always possible to identify all the species present in a given sample, likely due to the predominant parasitic load and the DNA quantity of each species. The results of this study confirm that ITS-1 is a useful molecular marker for identifying Eimeria species in domestic rabbits. Full article

Lop-eared and brachycephalic conformations have inconsistently been associated with dental abnormalities in pet and rescue rabbit populations. We investigated conformational risk factors for dental abnormalities in a pedigree population where conformation could be confirmed. Otoscopic oral examination was performed on breeder-volunteered pedigree rabbits at British Rabbit Council shows and studs. Multivariable models were used for risk factor analysis of 14 possible dental disease signs. In 435 rabbits examined, 68.28% showed no incisor abnormalities and 55.40% showed no cheek teeth abnormalities. Lop-eared rabbits had higher odds than erect-eared rabbits for ocular discharge (odds ratio [OR]: 4.034, p = 0.007) but not for any dental abnormalities. Erect-eared rabbits showed higher odds of reacting to incisor examination than lop-eared rabbits (OR: 1.666, p = 0.003). Brachycephaly showed no associations with dental abnormalities, whilst more dolichocephalic rabbits had increased odds of cheek teeth step or wave mouth (OR: 1.394, p = 0.004). Other conformational and signalment-related risk factor results were mixed. Brachycephaly showed no significant predisposition to dental abnormalities, and the clinical relevance of predisposition to ocular discharge in lop-eared rabbits is unclear. Conformation appears less important than husbandry factors for preventing rabbit dental disease. Generalising the results to companion rabbits is not advised due to husbandry and population differences. Full article

Background: European wild rabbits (Oryctolagus cuniculus) are closely connected to the natural environment and might be a potential source of pathogenic bacteria and/or antimicrobial-resistant bacteria. The objective was to identify the bacterial community (species and genera) that colonizes the nasal cavities of European wild rabbits as well as to study the antimicrobial resistance (AMR) phenotypes of bacteria of public health interest. Methods: A total of 147 nasal swabs individually collected from wild rabbits in Spain and Portugal (between 2022 and 2024) were studied. Samples were inoculated in different culture media, and isolates were identified by MALDI-TOF. The AMR phenotypes of staphylococci, mammaliicocci, enterococci and Enterobacterales were evaluated by the disk-diffusion method. Results: Overall, 557 non-repetitive isolates were obtained (1 isolate per species and AMR phenotype of each animal). A wide diversity of genera (n = 40) and species (n = 90) was found. Staphylococcus (21.2%), Mammaliicoccus (11.7%), Enterococcus (23.3%), Enterobacter (9.2%), Citrobacter (4.5%) and Escherichia (5.9%) were the most detected genera. Most animals presented more than one genera (78.9%), and in 15.7% of them, at least five genera were identified. Susceptibility to all antimicrobials tested was found in 37.2%, 38.5% and 51.6% of staphylococci/mammaliicocci, enterococci and Escherichia coli isolates; moreover, multidrug resistance was detected in 10.4%, 14.6% and 9.6% of these groups of bacteria. Moreover, important species of pathogenic bacteria were found, such as Yersinia enterolocolitica (0.5%) and Bordetella bronchiseptica (0.2%), among others. Conclusions: A high bacterial diversity was detected in the nasal cavities of European wild rabbits from the Iberian Peninsula, including pathogenic species and/or resistant strains of public health interest. Full article

The application high-intensity ultrasound (HIU) in rabbit meat has shown promising results for improving its palatability and commercial value. This study aimed to evaluate the effect of HIU application in meat from two rabbit breeds (Flemish Giant, FG and Azteca Negro, AN) on its physicochemical parameters (PQs) and sensory profile (SEN). Five carcasses of each breed were frozen and dorsally cut into half carcasses. HIU was applied (20 min, 50 kHz, and 200 W) to one randomly selected half carcass of each rabbit. PQs evaluated were pH, color (L*, a*, and b*), chroma (C*), hue angle (HUE), water holding capacity (WHC), collagen content, and shear force (SF). Color, odor, flavor, and texture were evaluated for the SEN. Statistical analysis was performed using ANOVA, adjusting a general mixed model with the fixed effects of treatment, breed, and their interaction. Significant interaction differences (p < 0.05) of breed and HIU were observed in the collagen content. Breed had an effect (p < 0.05) on pH, a*, b*, C*, and on the descriptors of the sensory attribute color. HIU had an effect (p < 0.05) on L*, a*, HUE, C*, and SF, as well as on sensory descriptors like texture and color. HIU increases the physicochemical and sensory perception of the tenderness of the meat of both breeds. Full article

This study examined the grazing pressure and interactions between four species of wild kangaroos (Red Kangaroo Osphranter rufus, Common Wallaroo O. robustus, Eastern Grey Kangaroo Macropus giganteus, Western Grey Kangaroo M. fuliginosus), free-ranging feral goats (Capra hircus) and European rabbits (Oryctolagus cuniculus), and stocked Merino sheep (Ovis aries). The study site comprised two contiguous pairs of stocked and unstocked paddocks, one a sloping run-off zone, the other a flat run-on zone, covering a total area of 2158 ha. These paddocks on Fowlers Gap Station in far north-western New South Wales, Australia, are representative of the arid chenopod (Family: Chenopodiaceae) shrublands stocked with sheep. Sheep and red kangaroos dominate the mammalian herbivores by biomass. The study examined the relative grazing pressure exerted by the seven species of mammalian herbivores in stocked and unstocked conditions, where only sheep were confined, across a three-year period that included rain-deficient (drought) months. The effects of climate (especially rainfall and temperature) and herbivore density on the standing biomass of pasture were teased out at a macro-scale. Herbivory at a micro-scale was examined using open and exclosed plots with detection of herbivore species by fecal deposition and time-lapse videography. Sheep exerted the highest grazing pressure and there was no compensatory increase in grazing pressure by other herbivores in unstocked paddocks. Rainfall was a key driver of pasture biomass and condition and loss by senescence typically outweighed grazing pressure. Grazing effects at a micro-scale were plot-specific and complex. The results are discussed in relation to the sustainable management of rangelands for production and wildlife. Full article

The European rabbit (Oryctolagus cuniculus) presents a significant conservation and management challenge in Greece. While it has been listed in national biodiversity assessments, its population dynamics on the island of Lemnos demonstrate the characteristics of a highly adaptable and rapidly expanding species, exerting substantial ecological and economic impacts. Addressing this issue requires a spatially explicit understanding of its distribution patterns and habitat preferences, particularly given its extensive population growth over the past three decades. To this end, we conducted 40 field surveys across the island, documenting 1534 presence records of the species. We applied Kernel Density Estimation, Getis-Ord Gi *, and Anselin Local Moran’s I to identify the spatial distribution patterns and significant hotspots. A spatial lag model was used to quantify hotspot intensity and clustering dynamics, while abiotic, biotic, and anthropogenic factors were analyzed to assess habitat associations. Our results revealed that rabbit hotspots are predominantly concentrated in fertile lowland agroecosystems, with nearly 60% of high-density areas overlapping conservation zones. Soil and field conditions, grazing-supporting landscapes, and arable and subsidized agricultural areas emerged as significant predictors of O. cuniculus presence. The observed spatial dependencies indicated that while hotspot intensities and clustering dynamics are influenced by the conditions in neighboring areas, habitat characteristics remain fundamental in shaping their distribution, highlighting the broader landscape-scale spatial patterns affecting rabbit populations. These findings underscore the necessity of adopting spatially informed management strategies that mitigate agricultural impacts while accounting for interconnected spatial dynamics, providing a foundation for informed decision-making to manage rabbit populations while balancing conservation and agricultural priorities. Full article

The use of agro-industrial by-products in livestock nutrition is of increased interest to the feed industry. Some of the by-products are rich in bioactive compounds that could lead to an increase in the quality of animal meat products. This study aimed to evaluate the effects of dietary incorporation of grape pomace (GP), a by-product rich in polyphenols, on growth and on the oxidation status and the fatty acid profile of rabbit meat. Forty-eight male rabbits (Oryctolagus cuniculus) (aged 55 ± 3 d and ca 2.3 kg) divided into three groups of 16 were used in the trial. The rabbits were housed in pairs in wire-mesh cages (26 × 46 × 35 cm) giving n = 8 for each diet treatment. The first group was fed a basal diet (CTR) (ca 18% protein and ca 4% fat), the second was given a basal diet supplemented with 5 g GP per head per day (low-GP) and the third group was fed a basal diet supplemented with 10 g GP per head per day (high-GP). The trial lasted three weeks, and the animals were weighed weekly. The rabbits were slaughtered, and the weight and the pH of the carcasses was measured immediately after slaughter and after 24 h of cooling at 4 °C. The pH of the stomach and cecum was measured. A sample of Longissimus Dorsi (LD) was collected and stored at −80 °C for the analysis of proximate composition, thiobarbituric acid reactive substances (TBARs) and fatty acid profile (FA). The diet did not influence the growth or the pH of the stomach and cecum of the rabbits. The chemical composition of the meat was similar in all groups, with a mean protein of 22.3% and fat of 0.95%. The fatty acid profiles of the LD were not influenced by the diet, and the most abundant FAs were C16:0, C18:2n6 and C18:1c9. Feeding GP to the rabbits gave a linear decrease of TBARs in the meat, indicating a reduction in oxidative stress. The TBARs’ reduction was 60% in the meat of the rabbits given high-GP compared to CTR. In conclusion, GP could be used in rabbit diets without any negative influence on meat quality but with an increase in oxidation stability that could enhance meat shelf-life. Full article