Autochthonous Transmission of Angiostrongylus Cantonensis in a Domestic Rabbit (Oryctolagus Cuniculus) in Hawai`i: Detection in Multiple Tissues Using AcanITS1 and AcanR3990 PCR Assays

Background: Hawaii is the hotspot for rat lungworm disease (angiostrongyliasis) caused by the nematode Angiostrongylus cantonensis in the USA. In humans, PCR of the CSF is typically used for diagnosis, however, collection of CSF requires hospitalization. Here, we evaluate the efficacy of two different PCR tests to detect A.cantonensis DNA in multiple tissues including blood from a rabbit presumably infected by eating contaminated lettuce. Methods: Two different PCR assays (AcanR3990, and AcanITS1) were used comparatively to test DNA extracted from slug and rabbit tissues. Assays were conducted using established protocols and were run in triplicate, with negative (dH20) controls included throughout. Results: A juvenile Parmarian martensi (semi-slug) found in local lettuce tested positive for the presence of Angiostrongylus cantonensis DNA. A family and their two domestic rabbits (Oryctolagus cuniculus) consumed this lettuce twice within the five days preceding testing. One rabbit exhibited symptoms consistent with eosinophilic meningitis 3-6 days after being fed the lettuce. Appropriate veterinary treatment was ineffective and the rabbit was subsequently euthanized. This study comparatively applies two different PCR assays to detect A. cantonensis DNA in the peripheral blood, cerebrospinal fluid, brain, heart, and lung tissue of this rabbit, and provides data implicating parasite transmission via contaminated home-grown lettuce. Six of the nine brain DNA samples, as well as the CSF sample, tested positive in replicate or triplicate for A. cantonensis DNA with both PCR assays. The AcanR3990 assay also detected A. cantonensis DNA from the lung, heart septum, all nine samples from the brain, and blood products (plasma, EDTA-treated whole blood, and buffy coat/red blood cells) in replicate or triplicate.

Cross-sectional Molecular Detection of Francisella tularensis in Domestic Rabbits in Sulaimani Province Kurdistan Region, Iraq

Tularemia is one of the diseases transmitted between humans and animals. It is caused by a Gram-negative bacterium Francisella tularensis. Recent serological studies suggested that tularemia can be an endemic bacterial zoonotic disease in some countries surrounding Iraq such as Iran and Turkey. The main objective of this study is to detect tularemia in Sulaimani province northeast Iraq near to Iran border. Sulaimani city also has contact with many Turkish cities. This study was conducted between Jun and October 2020. Blood samples were taken from one hundred local breed rabbits of different ages and sexes. A highly sensitive real-time PCR technique was used. Sixteen out of one hundred blood samples (16%) were positively taken from different local breed rabbits from four different places in Sulaimani province. All positive samples were detected in the center of Sulaimani city. No published documents have been reported yet about tularemia in Kurdistan Region. This paper documented molecular detection of F. tularensis in local breed rabbits in Sulaimani province Kurdistan Region-Iraq

Distribution and Genetic Diversity of Hepatitis E Virus in Wild and Domestic Rabbits in Australia

In 2020, Hepatitis E virus (HEV) was detected for the first time in Australian rabbits. To improve our understanding of the genetic diversity and distribution of the virus, 1635 rabbit liver samples from locations across Australia were screened via RT-qPCR for HEV. HEV genomes were amplified and sequenced from 48 positive samples. Furthermore, we tested 380 serum samples from 11 locations across Australia for antibodies against HEV. HEV was detected in rabbits from all states and territories, except the Northern Territory. Seroprevalence varied between locations (from 0% to 22%), demonstrating that HEV is widely distributed in rabbit populations across Australia. Phylogenetic analyses showed that Australian HEV sequences are genetically diverse and that HEV was likely introduced into Australia independently on several occasions. In summary, this study broadens our understanding of the genetic diversity of rabbit HEV globally and shows that the virus is endemic in both domestic and wild rabbit populations in Australia.

Morphological and Molecular Identification of Passalurus Ambiguus Rudolphi, 1819 in Domestic Rabbits (Oryctolagus Cuniculus) in Qena Governorate, Upper Egypt

Domestic rabbits in Egypt are used commercially for meat, but gastrointestinal disorders can affect production. Passalurus ambiguus is an intestinal parasite that infects the rabbit causing intestinal problems and death in severe cases. The present study collected domestic rabbits from several locations tgroughout the Qena Governorate in Upper Egypt. Passalurus ambiguus worms were detected in 90 out of 200 rabbits (45%). They were described morphologically using light and scanning electron microscopy. Males measured 4.622 mm (2.838–7.172 mm) in length and 0.278 mm (0.139–0.558 mm) in width. Females measured 5.622 mm (2.347–9.532 mm) in length, 0.314 mm, and (0.185–0.381 mm) in width. Phylogenetic results confirmed the identification of the worms as Passalurus ambiguus. They appeared as small white nodules in the appendix of the rabbits examined. Histopathologically, a heavy worm burden was observed inside the appendiceal lumen, among crypts, and inside the lymphoid follicles. The heavy worm infestation leads to hyperplasia in the epithelial lining of the appendix and the follicles resulting in lumen obstruction. Granulomatous reactions were induced due to irritation and injury by the worm. It could be concluded that morphological features, molecular phylogenetic data, and histopathological findings clearly identified the present species as as Passalurus ambiguus Rudolphi, 1819.

Specifics of the morphological identification of the pathogen of passaluariasis of rabbits

Passalurus ambiguus (Nematoda, Oxyuroidae) is one of the most common parasites of digestive tract of domestic and wild rabbits and rodents. Passalurus spp. are cosmopolitan, and the mature nematodes are localized in the appendages and large intestine of animals. The passaluariasis infections remain quite relevant in modern rabbit breeding, because the disease is highly contagious, with the possibility of unlimited spread inducing significant economic losses. The aim of the study was to determine the identifying morphological species characteristics of P. ambiguus nematodes, which were isolated from the colon of domestic rabbits (Oryctolagus cuniculus domesticus). The identifying characters of Passalurus include morphological features, namely the presence of a spherical bulb in the esophagus, and the presence of three teeth in the oral capsule. Males of P. ambiguus have a characteristic structure of the tail end, namely the presence of papillary protrusions and a massive narrowed part with a spicule handle, and five papillae around the cloaca. Twenty-eight metric indicators are proposed that characterize the size of the body, oral capsule, esophagus in different parts of it, the tail end, spicules, the location of the cloaca. Two different morphotypes of mature females of P. ambiguus were revealed – short-tailed and long-tailed, which were larger by 19 indicators (by 3.2–43.6%). The morphotypes of P. ambiguus females are characterized; the length of the tail, body length and width in different areas, depth of the oral capsule, esophageal size and its structural elements, the location of the vulva and nerve ring, the width of the caudal process. At the same time, the parameters of esophageal bulb length and caudal process in short-tailed females were higher (by 13.9% and 11.9%, respectively) than in the long-tailed females. A total of 25 morphometric parameters were proposed for the identification of P. ambiguus females. The obtained data indicate the feasibility of further research on the causes of occurrence of such morphotypes in P. ambiguus females and the need to take into account the existence of such forms of females for their differential diagnosis taking into account their proposed morphometric parameters.

Clinical presentation and management of liver lobe torsions in domestic rabbits

Rabbits (Oryctolagus cuniculus) are common household pets, and make endearing companions for both the young and old. Rabbit medicine has advanced greatly in recent years, and we are now able to recognise, diagnose and treat many conditions and presentations that may have previously been poorly understood. One of the conditions that is increasingly recognised is liver lobe torsion, which can prove difficult to recognise in clinical practice, especially if the team has not encountered the condition before. The purpose of this article is to highlight liver lobe torsions in rabbits, their presentation and treatment options and nursing care, and describe a successful case seen at the clinic.

Evaluation of various salt addition levels in the pellets on performance and health of the domestic rabbit urination system

This research aims to evaluate the various salt addition levels in the pellets on the performance and health of the domestic rabbit urination system. The completely randomized design method was used to determine the 5 levels of salt addition to the treatment, namely P1, P2, P3, P4, and P5 with 0%, 0,175%, 0,25%, 0,375%, and 0,50%. The sample consists of 20 male domestic rabbits aged 8 weeks with an average body weight of 897,05 ± 68,27g, which were kept in individual cages. The variables of these rabbits were analyzed to determine their performance and urinalysis using Anova (analysis of variance) and correlation analysis. The Anova results showed that salt addition levels in the pellets had a significant effect on FI, WI, FCR, UV, Nit, Pro (p<0,05), and insignificant on BWG, pH, Leu, Uro, Blo, Ket, Bil, Glu, and SG (p>0,05). The results further showed the correlation on several variables of performance and urinalysis. In conclusion, the optimal level of salt addition in the pellets was 0,25% because it give the lowest value of feed conversion ratio and does not adversely affect the health of the domestic rabbit urination system.

The distribution of lagomorph syphilis caused by Treponema paraluisleporidarum in Europe

Treponema paraluisleporidarum infects both rabbits (ecovar Cuniculus) and hares (ecovar Lepus). While the occurrence of the bacterium has previously been reported for European brown hares (Lepus europaeus) and domestic rabbits (Oryctolagus cuniculus f. domestica), there are no data available that report infection in the European context. We tested a total of 1,995 serum samples and 287 genital swabs from opportunistically sampled European brown hares (Lepus europaeus; n = 2135), Mountain hares (Lepus timidus; n = 4), European rabbits (Oryctolagus cuniculus; n = 138), and pet rabbits (O. cuniculus f. domestica; n = 5). The samples originated from eight European countries. In case only serum was available, we tested the samples for the presence of anti-treponemal antibodies. For this, we utilized the Treponema pallidum-particle agglutination test (TP-PA), which is suited for the use in lagomorphs due to the antigenic cross-reactivity of anti-T. pallidum and anti-T. paraluisleporidarum antibodies. In addition, the results of 380 sera were confirmed using the fluorescent-Treponema antibody absorption test (FTA-ABS). In all cases where swab samples were available, DNA was extracted and tested using quantitative PCR to test for the presence of the lagomorph syphilis-bacterium. We were able to detect antibodies in 825 of 1,995 lagomorph sera (41.4%; brown hare: 825/1,868; rabbit: 0/127) and obtained positive qPCR results from 182 of 287 swab samples (63.4%; European brown hare: 167/267; mountain hare: 4/4; rabbit: 11/16). While all rabbit sera (n = 127) tested negative for anti-treponemal antibodies, the presence of the bacterium was confirmed in eight wild (n = 8/11) and three domestic rabbits (n = 3/5) from Germany using qPCR.