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Abstract Background Rabbits are popular family pets. They are prey species and so have evolved to hide signs of illness and pain. Recent research has developed robust pain scales for use in a clinical setting, but to date none has examined rabbit owners’ ability to recognise pain in their animals. This study investigated how owners identify pain in their pet rabbits and their ability to correctly identify different levels of pain, in order to determine any need for owner education in this area. Methods Owners were recruited via Facebook and a two-part online survey was distributed. Part one collected data on demographics, owners’ knowledge of pain signs and beliefs about pain in rabbits. Part two asked respondents to pain score eight videos of rabbits in different levels of pain for comparison to pain scores made by three experts. We used a simplified version of the Bristol Rabbit Pain Score (BRPS) which involved a single 0 to 3 scale. We explored the number of pain signs each respondent could list, the total score given to the videos, and their deviation from the experts’ scores. Results A total of 500 respondents completed part one of the survey and 345 additionally completed Part two. Respondents were on average able to state five signs of pain (range 0–12), but females stated significantly more (p = 0.018), as did those who worked with rabbits (p = 0.004) and those with experience of their rabbit having an operation (p = 0.01). Overall, 98.6% of respondents thought rabbits felt pain as much or more that dogs and cats. In Part two, respondents more frequently agreed with the experts when identifying rabbits in no pain (88.8%) and severe pain (65.2%), but there was lower agreement when identifying mild (28.4%) and moderate pain (43.2%). Respondents overall rated pain lower than experts with an average total pain score of 11.9 compared to 18 given by the experts. Conclusions Most rabbit owners are able to list numerous pain signs and are generally able to identify pain-free rabbits and those in severe pain. Owners’ ability to differentiate between mild and moderate pain is more limited and could benefit from training in the subtler signs of pain. Veterinary professionals are well placed to educate owners about signs of pain in rabbits and should be aware of areas where owners’ knowledge can be improved.

Rabbit oncology is gaining more attention as more pet rabbits are surviving beyond their normal lifespans. Due to the limited epidemiological information on pet rabbits’ tumors in Thailand, this study aimed to report the prevalence and the potential risk factors associated with tumors in pet rabbits in Thailand. From 2018 to 2022, 93 tissue biopsies from tumor-suspected lesions on pet rabbits were gathered from animal hospitals in Bangkok and Chonburi provinces, Thailand. According to histopathology confirmation, tumors and tumor-like lesions were diagnosed. In this study, the overall tumors were 67.74% (n=63) out of the submitted cases (n=93). The most commonly affected organ systems were reproduction (65.08%) and integumentary (22.22%). Rabbits older than 5 years were 3.85 times more likely to have reproductive tumors than younger rabbits (95% confidence interval (CI): 1.45–10.27, P≤0.01), and the most frequently occurring tumor type was uterine adenocarcinoma. Furthermore, male rabbits had a 17.02 times higher probability of developing cutaneous tumors than female rabbits (95% CI: 4.19–69.11, P≤0.001), and the most frequently occurring tumor type was soft tissue sarcoma. The results of this study thus suggested that the age and sex of the rabbits were potential risk factors for tumor development in Thailand. The knowledge gained from our study also provided the recommendation for owners to monitor their rabbits’ health annually, particularly after late middle age, and rendered guidance for tumor detection in practical clinics. [ABSTRACT FROM AUTHOR]

Spontaneous pneumothorax is uncommon in rabbits and could severely affect the respiratory status of the animals. This retrospective case series aimed to provide clinical and diagnostic imaging data associated with this pathological finding in pet rabbits. Medical records over the past five years (2017–2022) were reviewed. Four cases were identified: three female and one male rabbit between 5 and 7 years of age. Three rabbits had no history of respiratory signs, and two rabbits presented with respiratory distress. Radiographs revealed severe pneumothorax in two patients. Computed tomography (CT) findings revealed moderate unilateral pneumothorax (3/4) and bilateral pneumothorax (1/4). Other concurrent pulmonary findings included emphysematous bullae (2/4), cavitary lesions (1/4), and neoplasia (1/4). An infectious component was suspected in all cases and all rabbits were treated with a combination of antibiotics. Several thoracocenteses were performed and chest tubes were inserted in two rabbits. Three rabbits died shortly after the CT scan, whereas the last rabbit recovered temporarily. Histopathology was performed in two cases. The first rabbit had mild-to-severe chronic multifocal granulomatous pneumonia, nephritis, and hepatitis. The second case showed a large epithelioid cell tumor consistent with histiocytic sarcoma. Spontaneous pneumothorax is a severe condition that may be life-threatening in pet rabbits. The four cases described provide information about clinical management, evolution over time, and potential etiology. [ABSTRACT FROM AUTHOR]

ABSTRACT The concern about pain management in exotic mammals is increasing. However, only a few studies describe locoregional anesthesia techniques in rabbits. Thus, this report aims to describe the lumbar paravertebral block, guided by peripheral nerve stimulation, in a rabbit undergoing mid-femoral amputation. We received a one-year-old rabbit weighing 1.27kg with a history of non-union of the right femur and osteomyelitis. The animal came to us for high pelvic limb amputation. After premedication with ketamine, midazolam, and morphine, the patient was maintained under general anesthesia in a non-rebreathing circuit under spontaneous ventilation with isoflurane vaporized in 0.6 oxygen. Using a peripheral nerve stimulator, we performed the lumbar paravertebral block, positioning the needle between the L5 and L6 vertebrae and injecting 0.2mL/kg bupivacaine. The patient remained stable throughout the procedure, without the need for analgesic rescue with opioids during surgery and postoperatively. The discharge occurred after 24 hours. The lumbar paravertebral block proved efficient for trans and postoperative analgesia for high pelvic limbic amputation in rabbits.

Background: Antiparasitic drug toxicosis is commonly described in dogs and cats, but reports on the management of antiparasitic drug toxicities in pet rabbits are scarce. Here, we describe the successful clinical management of two pet rabbits with fipronil toxicosis. Cases Description: The first case (case 1) was a 5-month-old, intact female, rabbit presented with acute onset of seizures, obtunded mentation and in lateral recumbency, while the second rabbit (case 2) was a 1-year-old, intact male presented for anorexia and lethargy. In both cases the owners reported to have administered a 0.5 ml fipronil vial topically on the skin as an antiparasitic drug between 4-6 hours prior presentation. Complete blood count and serum biochemistry were unremarkable and both rabbits tested negative on Encephalitozoon cuniculi serology. Both animals were decontaminated by bathing with tepid water and dishwashing soap. The rabbit with seizures received on admission intravenous midazolam. In both cases overnight hospitalization, intravenous isotonic crystalloid fluids as well as assisted-feeding by oral syringe was provided until voluntary feeding was resumed. Both rabbits rapidly improved approximately 12 hours of initiating supportive care. Complete resolution of clinical signs and return of normal appetite and defecation occurred within 24 hours of hospitalization in both animals. No recurrence of neurological signs was reported in the rabbit presented with seizures on a follow-up period of one month. Conclusion: The outcome of these cases suggests that supportive treatment of fipronil toxicity in pet rabbits can be successful if administered promptly.

Copyright of Summa, Animali da Compagnia is the property of Point Veterinaire Italie s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Summa, Animali da Compagnia is the property of Point Veterinaire Italie s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Summa, Animali da Compagnia is the property of Point Veterinaire Italie s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

PICO question In rabbits with cheyletiellosis is topical selamectin or injectable ivermectin a more effective treatment? Clinical bottom line Category of research Treatment. Number and type of study designs reviewed One paper directly answered the PICO question, a retrospective clinical design study, and was critically reviewed. Strength of evidence. Strong. Outcomes reported Both topical selamectin and injectable ivermectin are safe and effective in treating cheyletiellosis. There is no significant difference in the effectiveness of both drugs in treating the infestation. Conclusion In pet rabbits with Cheyletiella parasitivorax infestations both topical selamectin and injectable ivermectin have been recognised to be a safe and effective treatment. There is currently insufficient evidence that one is more effective than the other and therefore veterinarians should consider their own clinical experience, client preference and use the licensed product first (in the UK, ivermectin (Xeno, Dechra) spot-on). However, this Knowledge Summary does not comment on the effectiveness of topical ivermectin in treating cheyletiellosis. If injectable ivermectin is , topical selamectin can be used under the cascade as an alternative treatment, as it is licensed for the same indication in dogs and cats. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Encephalitozoon cuniculi (E. cuniculi) is a microsporidian parasite commonly detected in rabbits and can infect humans and cause encephalitozoonosis. And Toxoplasma gondii is a prevalent parasite distributed worldwide and can infect almost all warm-blooded animals, including humans. The aim of the current study was to investigate the seroprevalence of E. cuniculi and Toxoplasma gondii, and risk factors of infection in pet rabbits reared in eastern coastal areas of China (Tianjin, Shandong, Jiangsu, Zhejiang, Shanghai and Fujian). Total 222 blood samples of pet rabbits were collected from local veterinary hospitals. The seropositivity rates of E. cuniculi were 16.22% (36/222) according to an Enzyme-linked immunosorbent assay (ELISA). Female pet rabbits was significantly higher than that in males (P=0.002), Zhejiang were markedly higher than those in Jiangsu and Shanghai (P=0.017, P=0.022), and cross-breed rabbits were dramatically higher than those in Chinchilla, New Zealand white, Rex (P=0.02, P=0.006, P=0.008). The seroprevalence of T. gondii was 13.06% (29/222) by the method of ELISA. The seroprevalence in Zhejiang was significantly higher than that in Shanghai (P=0.017). No difference in seroprevalence was detected with respect to the gender, age, species, health status, or season. These findings show that E. cuniculi and T. gondii are present and spread in pet rabbits. Therefore, pet rabbits should be considered as an important reservoir of encephalitozoonosis for humans and maybe important implication for public health in eastern coastal areas of China. [ABSTRACT FROM AUTHOR]

The number of pets such as dogs, cats, rabbits, and parrots has increased in European families. Social benefits to owners such as decreasing feelings of loneliness and anxiety are provided by pets which are also used in Animal-assisted Therapy (AAT). Nevertheless, human-animal interactions are also associated with health problems including allergies, asthma, and zoonosis. Rabbits may carry potential pathogens for humans. One of the most common bacteria that colonizes the oro-pharynx and the upper respiratory tract of rabbits is Pasteurella (P.) multocida. Transmission of the infection to humans results from scratches, licks, and bites but it also can occur from the inhalation of air particles containing the microorganism. Immunocompromised people or persons with pulmonary disorders are particularly susceptible to the infection. Infected rabbits may carry P. multocida with or without clinical signs. In this paper, the sensitivity to antibiotics and the invasiveness ability of P. multocida identified in a farm of pet rabbits affected by severe pasteurellosis were investigated. The strain was P. multocida belonging to capsular type A which is the type most often detected in humans. The identified strain was susceptible to the tested antibiotics, but it appeared equipped with several virulence genes which are responsible for fimbriae production, adhesion processes to host cells, enzyme production, and are involved in iron acquisition processes. These findings are of particular interest because rabbits recovered from pasteurellosis very often become carriers of the bacteria. Therefore, we suggest considering P. multocida screening in the routine medical checks of rabbits, especially if they are meant to be companion animals for children and elder people, given that the transmission of the pathogen cannot be excluded. [ABSTRACT FROM AUTHOR]

Background: Antiparasitic drug toxicosis is commonly described in dogs and cats, but reports on the management of antiparasitic drug toxicities in pet rabbits are scarce. Here, we describe the successful clinical management of two pet rabbits with fipronil toxicosis. Cases Description: The first case was a 5-month-old, intact female, rabbit that presented with the acute onset of seizures, obtunded mentation, and in lateral recumbency, while the second rabbit was a 1-year-old, intact male, rabbit that presented with anorexia and lethargy. In both cases, the owners reported to have administered a 0.5 ml fipronil vial topically on the skin as an antiparasitic drug between 4 and 6 hours prior to presentation. Complete blood count and serum biochemistry were unremarkable and both rabbits tested negative on Encephalitozoon cuniculi serology. Both animals were decontaminated by bathing with tepid water and dishwashing soap. The rabbit with seizures received on admission intravenous midazolam. In both cases, overnight hospitalization, intravenous isotonic crystalloid fluids, and assisted-feeding by oral syringe were provided until voluntary feeding was resumed. Both rabbits rapidly improved approximately 12 hours of initiating supportive care. Complete resolution of clinical signs and return of normal appetite and defecation occurred within 24 hours of hospitalization in both animals. No recurrence of neurological signs was reported in the rabbit presenting with seizures on a follow-up period of 1 month. Conclusion: The outcome of these cases suggests that supportive treatment of fipronil toxicity in pet rabbits can be successful if administered promptly. [ABSTRACT FROM AUTHOR]

The number of pets such as dogs, cats, rabbits, and parrots has increased in European families. Social benefits to owners such as decreasing feelings of loneliness and anxiety are provided by pets which are also used in Animal-assisted Therapy (AAT). Nevertheless, human-animal interactions are also associated with health problems including allergies, asthma, and zoonosis. Rabbits may carry potential pathogens for humans. One of the most common bacteria that colonizes the oro-pharynx and the upper respiratory tract of rabbits is Pasteurella (P.) multocida. Transmission of the infection to humans results from scratches, licks, and bites but it also can occur from the inhalation of air particles containing the microorganism. Immunocompromised people or persons with pulmonary disorders are particularly susceptible to the infection. Infected rabbits may carry P. multocida with or without clinical signs. In this paper, the sensitivity to antibiotics and the invasiveness ability of P. multocida identified in a farm of pet rabbits affected by severe pasteurellosis were investigated. The strain was P. multocida belonging to capsular type A which is the type most often detected in humans. The identified strain was susceptible to the tested antibiotics, but it appeared equipped with several virulence genes which are responsible for fimbriae production, adhesion processes to host cells, enzyme production, and are involved in iron acquisition processes. These findings are of particular interest because rabbits recovered from pasteurellosis very often become carriers of the bacteria. Therefore, we suggest considering P. multocida screening in the routine medical checks of rabbits, especially if they are meant to be companion animals for children and elder people, given that the transmission of the pathogen cannot be excluded.

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the present study was to evaluate the effects of the inclusion of whole seeds of white lupine and different binder types in complete pelleted diets on selected haematological and plasma biochemical indicators of growing dwarf rabbits. The individual litters of Dwarf Lop rabbit kits were randomised after birth into control (n = 12) and experimental (E) groups. The young rabbits of the E group (n = 24) received an experimental pre-weaning diet containing a 25% share of white lupine seeds. At the time of weaning, the live weights of eight-week-old rabbits in the control group and E group were 727 g and 743 g, respectively. The weaned rabbits of the E group were further equally divided into two post-weaning experimental dietary groups (M = 12; G = 12); these diets contained a 20% share of white lupine seeds each and their composition only differed in the type of the binder (molasses or glycerol component). The rabbits of the control group received a commercial pet rabbit diet with no white lupine seeds during the entire experimental period. At the age of eight weeks, the diet showed a significant effect on the level of albumin (P < 0.05), A/G ratio (P < 0.05) and ALP activity (P < 0.01) in plasma of dwarf rabbit kits. Significant effects of diet were found in 15-week old rabbits in relation to the plasma level of albumin (P < 0.05), Ca (P < 0.05), A/G ratio (P < 0.05) and ALT activity (P < 0.01). The dietary inclusion of white lupine seeds resulted in beneficial health effects on certain blood indicators of rabbits, and their use in the proportion of 25% in the pre-weaning diet and 20% in the post-weaning diet can be recommended as a suitable feed additive for dwarf rabbits. The use of crude glycerol as binder in the experimental diet had no adverse effect on the blood indicators of the growing rabbits and thus it can be recommended for the manufacture of feed pellets intended for dwarf rabbits.

We tested 144 pet rabbits sampled in France between November 2020 and June 2021 for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by microsphere immunoassay. We reported the first evidence of a natural SARS-CoV-2 infection in rabbits with a low observed seroprevalence between 0.7% and 1.4%.

Rabbit haemorrhagic disease (RHD) is a highly contagious infectious disease of European wild and domestic rabbits. Rabbit haemorrhagic disease virus (RHDV, GI.1) emerged in 1986 in Europe, rapidly spreading all over the world. Several genotypes of RHDV have been recognised over time, but in 2010, a new virus (RHDV2/RHDVb, GI.2) emerged and progressively replaced the previous RHDV strains, due to the lack of cross-immunity conferred between RHDV and RHDV2. RHDV2 has a high mutation rate, similarly to the other calivirus and recombines with strains of RHDV and non-pathogenic calicivirus (GI.4), ensuring the continuous emergence of new field strains. Although this poses a threat to the already endangered European rabbit species, the available vaccines against RHDV2 and the compliance of biosafety measures seem to be controlling the infection in the rabbit industry Pet rabbits, especially when kept indoor, are considered at lower risk of infections, although RHDV2 and myxoma virus (MYXV) constitute a permanent threat due to transmission via insects. Vaccination against these viruses is therefore recommended every 6 months (myxomatosis) or annually (rabbit haemorrhagic disease). The combined immunization for myxomatosis and RHDV through a commercially available bivalent vaccine with RHDV antigen has been extensively used (Nobivac® Myxo-RHD, MSD, Kenilworth, NJ, USA). This vaccine however does not confer proper protection against the RHDV2, thus the need for a rabbit clinical vaccination protocol update. Here we report a clinical case of hepatitis and alteration of coagulation in a pet rabbit that had been vaccinated with the commercially available bivalent vaccine against RHDV and tested positive to RHDV2 after death. The animal developed a prolonged and atypical disease, compatible with RHD. The virus was identified to be an RHDV2 recombinant strain, with the structural backbone of RHDV2 (GI.2) and the non-structural genes of non-pathogenic-A1 strains (RCV-A1, GI.4). Although confirmation of the etiological agent was only made after death, the clinical signs and analytic data were very suggestive of RHD.

Rabbit oncology is gaining more attention as more pet rabbits are surviving beyond their normal lifespans. Due to the limited epidemiological information on pet rabbits' tumors in Thailand, this study aimed to report the prevalence and the potential risk factors associated with tumors in pet rabbits in Thailand. From 2018 to 2022, 93 tissue biopsies from tumor-suspected lesions on pet rabbits were gathered from animal hospitals in Bangkok and Chonburi provinces, Thailand. According to histopathology confirmation, tumors and tumor-like lesions were diagnosed. In this study, the overall tumors were 67.74% (n=63) out of the submitted cases (n=93). The most commonly affected organ systems were reproduction (65.08%) and integumentary (22.22%). Rabbits older than 5 years were 3.85 times more likely to have reproductive tumors than younger rabbits (95% confidence interval (CI): 1.45-10.27, P≤0.01), and the most frequently occurring tumor type was uterine adenocarcinoma. Furthermore, male rabbits had a 17.02 times higher probability of developing cutaneous tumors than female rabbits (95% CI: 4.19-69.11, P≤0.001), and the most frequently occurring tumor type was soft tissue sarcoma. The results of this study thus suggested that the age and sex of the rabbits were potential risk factors for tumor development in Thailand. The knowledge gained from our study also provided the recommendation for owners to monitor their rabbits' health annually, particularly after late middle age, and rendered guidance for tumor detection in practical clinics.

The aim of the present study was to evaluate the effects of the inclusion of whole seeds of white lupine and different binder types in complete pelleted diets on selected haematological and plasma biochemical indicators of growing dwarf rabbits. The individual litters of Dwarf Lop rabbit kits were randomised after birth into control (n = 12) and experimental (E) groups. The young rabbits of the E group (n = 24) received an experimental pre-weaning diet containing a 25% share of white lupine seeds. At the time of weaning, the live weights of eight-week-old rabbits in the control group and E group were 727 g and 743 g, respectively. The weaned rabbits of the E group were further equally divided into two post-weaning experimental dietary groups (M = 12; G = 12); these diets contained a 20% share of white lupine seeds each and their composition only differed in the type of the binder (molasses or glycerol component). The rabbits of the control group received a commercial pet rabbit diet with no white lupine seeds during the entire experimental period. At the age of eight weeks, the diet showed a significant effect on the level of albumin (P < 0.05), A/G ratio (P < 0.05) and ALP activity (P < 0.01) in plasma of dwarf rabbit kits. Significant effects of diet were found in 15-week old rabbits in relation to the plasma level of albumin (P < 0.05), Ca (P < 0.05), A/G ratio (P < 0.05) and ALT activity (P < 0.01). The dietary inclusion of white lupine seeds resulted in beneficial health effects on certain blood indicators of rabbits, and their use in the proportion of 25% in the pre-weaning diet and 20% in the post-weaning diet can be recommended as a suitable feed additive for dwarf rabbits. The use of crude glycerol as binder in the experimental diet had no adverse effect on the blood indicators of the growing rabbits and thus it can be recommended for the manufacture of feed pellets intended for dwarf rabbits. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to determine the incidence and the associated risk factors of peri-anaesthetic mortality and gastrointestinal complications in pet rabbits. Study design Retrospective cohort study. Animals A total of 185 pet rabbits admitted to the Exotic Referal Service of Beaumont Sainsbury’s Animal Hospital over the period 2009–2016. Methods The clinical records of the rabbits were obtained from the database. To evaluate the incidence of peri-anaesthetic mortality, three possible outcomes were considered: alive, dead or euthanized within the 72 hours following the anaesthetic event. Food intake and stool production during the first 72 hours following the anaesthetic event were evaluated to investigate the occurrence of gastrointestinal complications. Thereafter, various hypothesized risk factors, including administration of alpha-2 agonists, body weight, American Society of Anaesthesiologists classification and endotracheal intubation were tested against peri-anaesthetic mortality and gastrointestinal complications, with both univariate and multivariate binary logistic regression. Results Twenty-five out of 185 rabbits underwent two anaesthetic events; therefore, data from 210 cases were used. Of these 210 cases, six died during sedation or general anaesthesia and four (one of which euthanized) died during the first 72 postoperative hours, accounting for an actual mortality rate equal to 4.8% (95% confidence interval, 0.025–0.086). Peri-anaesthetic gastrointestinal complications developed in 77 (38%) out of the 204 anaesthetic events whose outcome was not intraoperative death (95% confidence interval, 0.314–0.446). Species-specific risk factors could not be identified for peri-anaesthetic mortality; however, the odds for post-anaesthetic gastrointestinal complications increased significantly with body weight ( p = 0.01). Conclusions and clinical relevance Our findings confirm that rabbits continue to have a higher incidence of peri-anaesthetic mortality than dogs and cats, and highlight a high risk for nonfatal peri-anaesthetic gastrointestinal complications in this species. [ABSTRACT FROM AUTHOR]

Most mammary tumors in pet rabbits are carcinomas; prognostic factors are unknown. The aim of this study on rabbit mammary carcinomas was to determine the expression of myoepithelial markers that have a prognostic relevance in human cancers. Mammary carcinomas (n = 119) of female or female-spayed pet rabbits were immunostained for cytokeratin AE1/AE3, vimentin, smooth muscle actin (SMA), and calponin; and percentages of non-neoplastic myoepithelial cells (ME cells) and calponin-positive neoplastic cells were determined. Using statistical analysis, data were correlated with the age of the rabbits and histological tumor characteristics. All carcinomas contained retained spindle-shaped ME, while 115 also contained hypertrophic ME (HME). A statistically significant relationship existed between a higher age and an increase in HME. In 111 carcinomas (93%), tumor cells expressed calponin. There was a significant correlation between higher percentages of calponin-positive tumor cells and a lower mitotic count, an increased percentage of tubular growth, and a lower grading score, respectively. Data suggest that pet rabbit mammary carcinomas develop from progression of in situ cancer and that the extent of calponin expression in tumor cells influences their biological behavior. These results provide the basis for a long-term follow-up on the prognostic significance of calponin expression in mammary cancer cells.

Rabbits are common pets in many European countries, including Italy. However, little is known about their behavior and general welfare. The purpose of this study was to explore behaviors of Italian domestic rabbits as perceived by their owners and to investigate the effect of sex on these behaviors after puberty. A group of 308 adult does was compared with a group of 326 adult bucks. Owners were asked to complete an online questionnaire eliciting information on themselves, their rabbits, and whether the animals exhibited any of 16 common behaviors. Pearson χ 2 test of independence in 2 × 2 contingency tables and binary logistic regressions were used to analyze the effects of sex on behavioral patterns while controlling for various owner- and rabbit-related variables. The odds of displaying owner-directed aggression and stranger-directed aggression were significantly greater for the does and neutered males than for the intact males. Bucks had a significantly higher likelihood of seeking contact with their owner. Our findings may provide insight into pet rabbit sex-related differences in behavior that may contribute to improving animal welfare and the rabbit companionship experience. These findings may have implications for future research aimed at studying behavioral disorders in pet rabbits. [ABSTRACT FROM AUTHOR]

An adult spayed female New Zealand white mix-breed rabbit was presented for an abnormal cutaneous pigmentation of the left nasal canthus. Biopsy samples were collected when the rabbit was under general anesthesia. Using the results of the biopsy, an initial diagnosis of carcinoma was made. The patient was referred for surgical excision followed by local radiation therapy using strontium-90. The histological appearance was most consistent with an amelanotic melanoma. Neoplastic cells strongly expressed melan-A and vimentin and failed to express pancytokeratin markers. The immunohistochemical findings supported the presumptive diagnosis of amelanotic melanoma. Owing to the high mitotic index, presence of neoplastic cells within the vessels, and incomplete surgical excision, the prognosis was poor. The owner refused further treatment and diagnostic evaluation of the patient. The rabbit was found dead in its enclosure approximately 6 months after the diagnosis. A postmortem examination was not performed. Although melanomas have been reported in rabbits, this condition appears to be underreported in pet rabbits. This case report describes the clinical presentation and diagnosis of amelanotic melanoma, histological evaluation of affected tissue, and immunohistochemistry in a rabbit. [ABSTRACT FROM AUTHOR]

Background The welfare of pet rabbits has become an area of growing interest in Europe and the UK. Some information does exist already on pet rabbits' housing, and associated health and welfare issues. In the UK, the information currently available is based on surveys of small sample sizes, single distribution media or restricted geographical spread, potentially representing a skewed demographic and limiting the generalisability of their findings. The present study analyses questionnaire results from a diverse population of 1254 rabbit owners from three different geographical areas in England with the aim of providing a more accurate representation of how pet rabbits are currently housed and cared for and key aspects of their health and welfare. Results Rabbits were found to be kept in a variety of different housing types, the most common being a traditional hutch/cage (59%). Most rabbits had been bought from a pet shop or garden centre (39.1%). Although the majority had additional exercise areas, access was often unpredictable, or ill-timed, which may compromise welfare. Only 41.9% of owners kept their rabbit with conspecifics, which limits their ability to engage in normal social behaviour and hence could be seen to negate one of the five basic welfare needs. Of those rabbits housed with a companion, although many were reported to be amicable and to engage in positive interactions, over a quarter were reported to fight at least occasionally (25.3%), whilst 22.7% guarded resources and 27.1% avoided one another. Regular chasing (22.7%) and mounting (14%) were also common. Although the vast majority of owners fed hay for over 10% this was less than daily. Pelletted or nugget foods were very popular with 71.4% of owners feeding them at least daily compared to 32.6% feeding commercial muesli mixes. As in previous studies, dental problems were commonly reported (12.2% of rabbits had experienced); however, so were eye problems (12.9%), digestive problems (11.5%) and parasites (11.3%). A large proportion of rabbits (58%) were reported to be fearful of loud noises such as fireworks, and 61% were not reported to be calm when handled by their owner, which may be a significant concern for this species. Development and validation of protocols to avoid and to overcome fears are therefore required. Conclusion This study has confirmed and expanded on previous findings: many pet rabbits were found to be in good health, had compatible companions and were provided with enriched living areas. Rabbits were kept in a wide variety of ways, of which many may meet their health and welfare needs. However, it also found numerous welfare issues that affect large numbers of pet rabbits. For example fighting, guarding resources, avoiding one another, chasing and mounting were all common. Whilst low levels of some of these behaviours may be a normal part of social interaction, the relatively high levels reported here suggest that not all cohabiting pairs of rabbits are compatible, which is potentially a significant welfare issue. We suggest further studies are required exploring the accuracy of owner reports (which possibly under-report many problems) and prioritising the issues raised here. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi (E. cuniculi) is a microsporidian parasite commonly detected in rabbits and can infect humans and cause encephalitozoonosis. And Toxoplasma gondii is a prevalent parasite distributed worldwide and can infect almost all warm-blooded animals, including humans. The aim of the current study was to investigate the seroprevalence of E. cuniculi and Toxoplasma gondii, and risk factors of infection in pet rabbits reared in eastern coastal areas of China (Tianjin, Shandong, Jiangsu, Zhejiang, Shanghai and Fujian). Total 222 blood samples of pet rabbits were collected from local veterinary hospitals. The seropositivity rates of E. cuniculi were 16.22% (36/222) according to an Enzyme-linked immunosorbent assay (ELISA). Female pet rabbits was significantly higher than that in males (P=0.002), Zhejiang were markedly higher than those in Jiangsu and Shanghai (P=0.017, P=0.022), and cross-breed rabbits were dramatically higher than those in Chinchilla, New Zealand white, Rex (P=0.02, P=0.006, P=0.008). The seroprevalence of T. gondii was 13.06% (29/222) by the method of ELISA. The seroprevalence in Zhejiang was significantly higher than that in Shanghai (P=0.017). No difference in seroprevalence was detected with respect to the gender, age, species, health status, or season. These findings show that E. cuniculi and T. gondii are present and spread in pet rabbits. Therefore, pet rabbits should be considered as an important reservoir of encephalitozoonosis for humans and maybe important implication for public health in eastern coastal areas of China.

Encephalitozoon cuniculi is a microsporidian parasite commonly found in rabbits that can infect humans, causing encephalitozoonosis. The prevalence of encephalitozoonosis is not well documented, even when many clinics suspect pet rabbits as being highly infected. This study investigated the seropositivity of E. cuniculi using ELISA. The examination of 186 rabbits using ELISA showed that 22.6% (42/186) were seropositive against E. cuniculi. In analysis with healthy status, all 42 seropositive sera were collected from clinically normal rabbits. Moreover, the gender and age of pet rabbits did not have anysignificant effect on E. cuniculi infection. To the best of our knowledge, this is the first report to describe the seroprevalence of E. cuniculi in pet rabbits and suggests that pet rabbits could act as an important reservoir of encephalitozoonosis for both pet animals and humans in Korea. [ABSTRACT FROM AUTHOR]

We tested 144 pet rabbits sampled in France between November 2020 and June 2021 for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by microsphere immunoassay. We reported the first evidence of a natural SARS-CoV-2 infection in rabbits with a low observed seroprevalence between 0.7% and 1.4%.

The article discusses the results of a study that examined the prevalence of Lawsonia intracellularis, Salmonella and Eimeria in feces of healthy and diarrheic pet rabbits. Topics discussed include the use of polymerase chain reaction (PCR) and formol-ether concentration method to test for pathogens and over 20 percent of normal and 97 percent of diarrheic rabbits were positive for single or concurrent infection of three pathogens.

Plant toxicity is a problem associated with feeding in rabbits which roam in houses or gardens. A 3-month-old pet rabbit ( Oryctolagus cuniculus) presented with acute sialorrhea, lethargy, anorexia, poor hair coat, tachypnea and with a history of Ponytail Palm ( Beaucarnea recurvata) ingestion 3 h before referral. No other abnormality was detected on physical examination. Complete blood count analysis was unremarkable. The case was treated based on conservative treatment including intravenous fluid therapy, antibiotic and sympathomimetic agent administration for 2 days. In the veterinary literature, reports of plant toxicity in rabbits are rare. This short communication is the first report of poisoning by B. recurvata in a pet rabbit. [ABSTRACT FROM AUTHOR]

Pet rabbits ( n = 125) from Southern Italy were submitted to a serological screening for Encephalitozoon cuniculi, using an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA). Seventy-eight examined rabbits showed clinical signs suggestive of encephalitozoonosis (head tilt, ataxia, paralysis, cataracts, uveitis, polyuria and polydipsia), whereas 47 were healthy rabbits. Antibodies anti- E. cuniculi were found in 84/125 (67.2%) sera analysed. The results of the chi-squared test showed that sex and health status had no significant effect ( P > 0.05) on E. cuniculi seropositivity; however, rabbits older than 4 months had a seropositivity for E. cuniculi significantly ( P < 0.05) higher than that of rabbits aged up to 4 months. The results of the present survey reinforce the assumption that rabbit may be indicated as the main reservoir of E. cuniculi; therefore, routine screening examinations in pet rabbits are strongly advised considering the zoonotic potential of this parasite. [ABSTRACT FROM AUTHOR]

Simple Summary: We report an unusual clinical case in a pet rabbit vaccinated against rabbit haemorrhagic disease virus (RHDV, GI.1), that developed a prolonged hepatic disease, and was diagnosed RHDV2 (GI.2) positive post-mortem. This finding is a warning to all veterinarians that rabbit haemorrhagic disease should also be considered for differential diagnosis despite the history of RHDV vaccination and the need to update vaccination programs against the current RHDV2 circulating strains. Rabbit haemorrhagic disease (RHD) is a highly contagious infectious disease of European wild and domestic rabbits. Rabbit haemorrhagic disease virus (RHDV, GI.1) emerged in 1986 in Europe, rapidly spreading all over the world. Several genotypes of RHDV have been recognised over time, but in 2010, a new virus (RHDV2/RHDVb, GI.2) emerged and progressively replaced the previous RHDV strains, due to the lack of cross-immunity conferred between RHDV and RHDV2. RHDV2 has a high mutation rate, similarly to the other calivirus and recombines with strains of RHDV and non-pathogenic calicivirus (GI.4), ensuring the continuous emergence of new field strains. Although this poses a threat to the already endangered European rabbit species, the available vaccines against RHDV2 and the compliance of biosafety measures seem to be controlling the infection in the rabbit industry Pet rabbits, especially when kept indoor, are considered at lower risk of infections, although RHDV2 and myxoma virus (MYXV) constitute a permanent threat due to transmission via insects. Vaccination against these viruses is therefore recommended every 6 months (myxomatosis) or annually (rabbit haemorrhagic disease). The combined immunization for myxomatosis and RHDV through a commercially available bivalent vaccine with RHDV antigen has been extensively used (Nobivac® Myxo-RHD, MSD, Kenilworth, NJ, USA). This vaccine however does not confer proper protection against the RHDV2, thus the need for a rabbit clinical vaccination protocol update. Here we report a clinical case of hepatitis and alteration of coagulation in a pet rabbit that had been vaccinated with the commercially available bivalent vaccine against RHDV and tested positive to RHDV2 after death. The animal developed a prolonged and atypical disease, compatible with RHD. The virus was identified to be an RHDV2 recombinant strain, with the structural backbone of RHDV2 (GI.2) and the non-structural genes of non-pathogenic-A1 strains (RCV-A1, GI.4). Although confirmation of the etiological agent was only made after death, the clinical signs and analytic data were very suggestive of RHD. [ABSTRACT FROM AUTHOR]

Simple Summary: The interaction between tumors and immune cells influences tumor fate, i.e., regression, growth, or even metastases. The evaluation of tumor infiltrating lymphocytes (TILs) in human breast cancer has prognostic value. Pet rabbits develop spontaneous mammary carcinomas and have an immune system that is comparable with that of humans, so that they have the potential to provide an animal model for human breast cancer. To further substantiate this similarity, this study examined TILs in 107 pet rabbit mammary carcinomas according to criteria established for human breast cancer. For TIL evaluation routinely stained microscopic sections were examined by light microscopy. Relevant histological and immunohistochemical tumor characteristics were obtained from a data base. Results showed that increased presence of stromal TILs was statistically associated with histological tumor features indicative of a less aggressive biological behavior, i.e., reduced tumor cell proliferation and a lower histological grade. The expression by tumor cells of calponin, a presumed tumor suppressor protein, was also associated with their reduced proliferation and a higher percentage of stromal TILs. Data suggest that higher percentages of stromal TILs may have the potential to serve as favorable prognostic indicator in rabbit mammary carcinomas and support the value of pet rabbits for comparative research. Tumor infiltrating lymphocytes (TILs) serve as prognostic biomarker in human breast cancer. Rabbits have the potential to act as animal model for human breast cancer, and close similarities exist between the rabbit and human immune system. The aim of this study is to characterize TILs in pet rabbit mammary carcinomas and to statistically correlate results with histological and immunohistochemical tumor characteristics. Microscopic evaluation of TILs was performed in hematoxylin and eosin stained sections of 107 rabbit mammary carcinomas according to international guidelines for human breast cancer. Data on histological features of malignancy, estrogen and progesterone receptor status and calponin expression were obtained from the data base. This study revealed a statistical association between stromal TILs in the central tumor (CT) and infiltrative margin. Higher maximal percentages of stromal TILs at the CT were statistically correlated with decreased mitotic count and lower tumor grade. An increased number of calponin positive tumor cells was statistically associated with a lower mitotic count and a higher percentage of stromal TILs. Results suggest that higher percentages of stromal TILs are useful biomarkers that may point toward a favorable prognosis in rabbit mammary carcinomas and support the concept of the use of rabbits for translational research. [ABSTRACT FROM AUTHOR]

Rabbit haemorrhagic disease (RHD) is a highly contagious infectious disease of European wild and domestic rabbits. Rabbit haemorrhagic disease virus (RHDV, GI.1) emerged in 1986 in Europe, rapidly spreading all over the world. Several genotypes of RHDV have been recognised over time, but in 2010, a new virus (RHDV2/RHDVb, GI.2) emerged and progressively replaced the previous RHDV strains, due to the lack of cross-immunity conferred between RHDV and RHDV2. RHDV2 has a high mutation rate, similarly to the other calivirus and recombines with strains of RHDV and non-pathogenic calicivirus (GI.4), ensuring the continuous emergence of new field strains. Although this poses a threat to the already endangered European rabbit species, the available vaccines against RHDV2 and the compliance of biosafety measures seem to be controlling the infection in the rabbit industry Pet rabbits, especially when kept indoor, are considered at lower risk of infections, although RHDV2 and myxoma virus (MYXV) constitute a permanent threat due to transmission via insects. Vaccination against these viruses is therefore recommended every 6 months (myxomatosis) or annually (rabbit haemorrhagic disease). The combined immunization for myxomatosis and RHDV through a commercially available bivalent vaccine with RHDV antigen has been extensively used (Nobivac ® Myxo-RHD, MSD, Kenilworth, NJ, USA). This vaccine however does not confer proper protection against the RHDV2, thus the need for a rabbit clinical vaccination protocol update. Here we report a clinical case of hepatitis and alteration of coagulation in a pet rabbit that had been vaccinated with the commercially available bivalent vaccine against RHDV and tested positive to RHDV2 after death. The animal developed a prolonged and atypical disease, compatible with RHD. The virus was identified to be an RHDV2 recombinant strain, with the structural backbone of RHDV2 (GI.2) and the non-structural genes of non-pathogenic-A1 strains (RCV-A1, GI.4). Although confirmation of the etiological agent was only made after death, the clinical signs and analytic data were very suggestive of RHD.

Rabbit bones are brittle and prone to fissure formation. Radiographs of very young and old rabbits are often indicative of decreased bone density. The aim of this study was to investigate the tibial bone parameters in pet rabbits, and their association with age, sex, castration and dental disease. Eighty-seven (43 female/5 spayed, 44 male/19 castrated) pet rabbits (mean age 2.6 years, range 0.3-9.3 years) of various breeds were studied, of which 37 had dental disease. Right tibiae were scanned with peripheral quantitative CT at the distal (4percent) and mid-shaft sites (50percent of the tibial length). Analysed bone parameters included the total cross-sectional area, cortical bone area and density, trabecular bone density and strength-strain index. The mean diaphyseal cortical density was high (about 1400 mg/cm 3 ) in comparison to many other species. Within the studied age range, age was weakly but positively associated with diaphyseal cortical density, with the juvenile rabbits clearly showing the lowest values. There was no tendency for age-related decrease in trabecular or cortical bone density at least up to six years of age. Neither were sex, castration nor dental disease associated with decreased tibial bone density., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2018. No commercial re-use. See rights and permissions. Published by BMJ.)