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.

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.

Rabbit Farming in India: An Overview

Domestic rabbit belongs to genus Oryctolagus cuniculus which has 38 important breeds and 77 varieties of European rabbits. The domestic rabbit is known to produce quality meat, fur and very fine quality animal fibre. Rabbit rearing has gained momentum in the recent years among the developing countries including India, owing to their small body size, rapid growth rate, high prolificacy, early maturity, shorter generation interval and ability to utilize forage and fibrous agricultural by-products. In India, there has been a rising awareness in recent years on the virtues of broiler rabbit production as an alternative means of alleviating food shortages. India is also one of the developing countries which are also facing meat shortage of 4.66 g/day against the recommended requirement of 87 g/day. In India, the total rabbit population has increased from 424 thousands in 2007 to 591.6 thousand in 2012 which is 39.55% increase in last 5 years.

Histological and Morphometrical Study of the Filiform Papillae in the Domestic Rabbit (Oryctolagus cuniculus)

The domestic rabbit is often preferred as an experimental model in diverse research and especially those regarding pathologies of the oral cavity, both in human and veterinary medicine. From five domestic mixed breed rabbits, fragments were harvested from the three regions of the tongue: apex, body and root, for histological investigations. The samples were processed by embedding in paraffin, sectioned at a thickness of 5 µm and stained with Goldner’s trichrome method. The histological examination highlighted the presence of the filiform papillae on the entire dorsal surface of the tongue, with morphological particular carachteristics for each portion. The dimension of the filiform papillae of the rabbit’s tongue differs both regarding the length as well as the thickness and density. The shortest filiform papillae were found on the tip of the tongue, then the length increases progressively, reaching the maximum level on the middle portion and decreases in the last portion. The density also differs, in in the three compartments examined, being the highest in the anterior part and the lowest in the posterior part. The thickness of the filiform papillae is inversely proportional to their density. The thickness of the papillae is smaller where the density is higher and highest where the density is lowest. The upper surface of the filiform papillae is variably keratinized depending on the lingual segment. The papillae with the highest level of keratinization are arranged in the body part of the tongue, and those at the tip and root are slightly lower.

Non-Invasive Measurement of Thyroid Hormones in Domestic Rabbits

Thyroid hormones are essential for metabolism, energy homeostasis and reproduction. Hormones can be measured in various biological source materials: blood, feces, urine, saliva and others. The aim of our study was to verify usefulness of thyroid hormone analysis in the urine and feces of the domestic rabbit (Oryctolagus cuniculus f. domesticus), comparing them with the serum analyses. Samples were collected from 27 does in the age of 12–14 weeks. Total thyroxine (tT4), total triiodothyronine (tT3), free thyroxine (fT4) and free triiodothyronine (fT3) were tested using the radioimmunological method in serum, feces and urine. The highest concentration of tT4 was found in feces (104.72 ± 59.52 nmol/mg) and the lowest in urine (3.03 ± 3.11 nmol/mL). The highest tT3 concentration was found in blood serum (3.19 ± 0.64 nmol/L) and the lowest in urine (0.31 ± 0.43 nmol/L). The highest concentration of fT4 was observed in feces (43.71 ± 4.79 pmol/mg) and the lowest in blood serum (14.97 ± 3.42 pmol/L). The statistically highest concentration of fT3 (28.56 ± 20.79 pmol/L) was found in urine, whereas the lowest concentration of this hormone was found in feces (3.27 ± 1.33 pmol/mg). There was a positive and statistically significant correlation between serum and urine fT3 (r = 0.76) and a high positive correlation between serum and feces fT3 concentration (r = 0.62). Correlations between concentrations of other thyroid hormones between serum, urine and feces were found to be insignificant. The results suggest that fT3 can be accurately and reliably measured in the feces and urine of the domestic rabbit.

Predication of body weight of the domestic rabbit at different stages of growth using linear body measurements

Data on body weight and linear body measurements (LBMs) namely ear length (EL), body width (BW), body length (BL), Head to shoulder (HS), Shoulder to tail (ST) and length of leg (LL) of 363 progeny of locally adapted Dutch , New Zealand White and crossbred rabbits at 3,6,9 and 12 weeks of age were analyzed to obtain phenotypic correlations between the various traits and prediction equations for body weight, using different linear body measurements. There were high and positive correlations between each of the linear body measurements and body weight and between the LBM themselves. The values ranged between 0.57 and 0.85, 0.34 and 0.89, 0.27 and 0.83 and 0.41 and 0.75 in weeks 3, 6, 9 and 12, respectively. Hence, it was possible to predict body weight of live rabbits from their linear body measurements, as an aid to farmers in areas where sensitive scales are not available. Except in purebred New Zealand White NZWxNZW, body: length (BL) was a good predictor of 3- week body weight (IBW) in all breed groups. Body width (BW) and BL only were good predictors of 6-week body weight in all breed groups. For predicting 9- week body weight, shoulder to tail drop (ST) was important in all breed groups in addition to either BW, ear length (EL) or body length (BL). ST and BW were important predictors of 12-week body weight generally in all breed groups.

Gastrointestinal Syndrome in a Rabbit (Oryctolagus cuniculus)

Background: The term “rabbit gastrointestinal syndrome” (RGIS) refers to a decrease in peristaltic movements, which in some cases can progress to absolute inactivity of the digestive apparatus. This condition is mostly secondary to others that promote changes in gastrointestinal motility, such as dehydration, fiber deficiency, excess carbohydrates in diets, stress, and acute or chronic painful processes. Clinical manifestations are mostly nonspecific. Thus, a case of RGIS resulting from environmental change in a domestic rabbit (Oryctolagus cuniculus) is reported.Case: A 4-month-old male domestic rabbit weighing 0.962 kg was referred to a university veterinary hospital. The patient had a history of absence of defecation and anorexia for the past two days. The owner reported that the patient was apathetic but became aggressive when manipulated. The changes started after a move of residence. On physical evaluation, an increase in abdominal volume and a painful response to touch on the abdomen were observed. Complementary examinations were performed, such as a blood count and an ultrasound study. The blood tests showed no alterations, but the ultrasound evaluation showed the presence of free abdominal fluid, dilated intestinal loops due to fluid content, reduced gastrointestinal motility, and a hyperechoic structure associated with acoustic shading in the small intestine, all findings suggestive of obstruction. Given the failure of clinical management, the patient was referred for an exploratory laparotomy procedure followed by enterotomy. The obstruction point was located near the ileocecal junction. After surgery, analgesics, antibiotics, fluid therapy, anti-inflammatory drugs, intestinal motility inducers, and probiotics were prescribed. One week after the surgical procedure, the patient showed improvement in the clinical condition, with normal appetite, defecation, and docility.Discussion: RGIS is diagnosed based on the clinical history, clinical manifestations, and complementary examinations. In the reported case, the patient presented apathy, anorexia, absence of defecation, and aggressiveness on manipulation, which were associated with abdominal pain. In cases of RGIS, hematological changes may or may not be present, which matches the findings in this report. Imaging exams provide important information, such as the patient’s condition and evolution. Ultrasound evaluation showed the presence of free abdominal fluid, dilated intestinal loops due to fluid content, reduced gastrointestinal motility, and a hyperechoic, immobile acoustic shading structure in the small intestine. Ultrasound findings were compatible with those found in cases of foreign-body obstructions, a common complication in RGIS. Initially, a clinical approach was taken, but in view of the unfavorable evolution of the case, with worsening motility and alterations in the imaging examination, a surgical approach was instituted. Intestinal obstructions in rabbits are usually found either in the proximal duodenum or near the ileocecal junction. In the presently reported patient, an obstruction was identified in the ileocecal junction region and the content found was composed of hair and dehydrated food. There are several conditions that can alter intestinal peristalsis in rabbits; in the present case, it was considered that the distress caused by moving to a new household led to a condition of RGIS. Despite the reserved prognosis associated with surgical interventions in the gastrointestinal system of rabbits, as described in the literature, in the present case this approach made it possible to preserve the patient’s life, which returned to its normal activities and behavior.

Influence of additive and non-additive gene effects on body measurements in the domestic rabbit

General Combining Ability (GCA) and Specific Combining Ability (SCA) were used to determine the influence of additive and non-additive gene effects on growth parameters, using 2 kits produced in full diallel crosses involving three breeds of rabbits namely, New Zealand White (NZW), Dutch (DT) and Chinchilla (CH). GCA was significant (P<0.05) for four out of the twelve traits studied, namely Body length (BL), Heart girth (HG), Ear length (EL) and Tail Length (TL). GCA values ranged from-12.594 for body weight (BWT) to 0.041 for the length of the hind limb (LHL) for NZW, -3.836 for BWT 10 0.123 for Head Circumference (HC) for DT and -0.035 for Head-to-shoulder (HS) and 16.431 for BWT for Chinchilla. SCA was significant (P<0.05) for HS only. SCA estimates ranged from -0.016 (BWT) to 0.187 (HG), 1.018 (BL) to 10.22 (BWT) and -17.09 (LHL) to 7.354 (BWT). for NZW x DT, NZW x CH and DTX CH crosses, respectively. The significant GCH observed in the four growth parameters indicates that genes governing them aci mainly additively. This implies that they may be genetically improved by selection and pure breeding. Significant SCA for HS is an indication that genes governing this character impart non-additive effects, suggesting that improvement could be brought about by exploiting crossbreeding and by improving the environment.