Rabbit dental disease and calcium metabolism – the science behind divided opinions

Dental disease is considered as one of the, if not, the most common disorders seen in pet rabbits. This article provides a review of the scientific literature and an overview of the peculiarities of calcium homeostasis in the rabbit in an attempt to draw together current thinking on the cause of dental disease. A complete understanding of the aetiology and pathophysiology of rabbit dental disease is necessary for the veterinary practitioner to establish a proper therapeutic plan, prognosis and ultimately prevention of this common cause of morbidity and mortality in pet rabbits.     

Rabies virus infection in a pet guinea pig and seven pet rabbits

Raccoon-variant rabies was confirmed in 7 pet rabbits and 1 pet guinea pig in New York State, and postexposure treatment was required in several adults and children. To prevent rabies virus infection, domestic rabbits and pet rodents should be protected from contact with wild animals, including double-cage housing when housed outside. Pet rabbits or rodents with any possible contact with a wild animal, particularly if the rabbit or rodent had wounds of unknown origin, should be quarantined for 6 months for observation, to prevent escape, and to avoid contact with humans, who will require treatment if the rabbit or rodent develops rabies. Bites and scratches to humans from rodents and lagomorphs should be evaluated for potential rabies exposure on an individual basis, with consideration of whether the animal was caged outside or permitted outdoors unsupervised.     

Anesthesia and Analgesia in Rabbits and Rodents

Rabbits and rodents are popular pets and are often presented to veterinarians for evaluation and medical treatment. Anesthesia in exotic pets is required for many diagnostic and surgical procedures and is associated with a higher perioperative risk in rabbits and rodents when compared with dogs and cats. Inhalation anesthetic agents are commonly used as the sole source of anesthesia in small rodents, whereas injectable agents in combination with inhalation anesthesia are often used for rabbits and larger rodents. Analgesia is an important component of exotic pet medicine. Although it may be difficult to recognize signs of pain in companion exotic mammals, adequate pain management should always be provided. Opioid and nonsteroidal antiinflammatory drugs are the analgesic medications of choice, but others should be considered (e.g., local anesthetic agents). This article provides an update of the current literature regarding anesthesia and analgesia in rabbits and rodents.     

Obesity in pet rabbits (Oryctolagus cuniculus): A narrative review

IntroductionObesity reduces both the longevity and the quality of life of pet animals. For pet rabbits, there is a dearth of research focusing on obesity. This paper provides an overview of the available information on obesity in rabbits and discusses approaches to its prevention and treatment.MethodThe prevalence of being overweight/obesity in pet rabbits varies from 5.9% to 35%, depending on study origin and assessment method. Six potential risk factors for rabbit obesity are identified, namely age, breed, sex and neutered status, diet, housing, and owner characteristics.ConclusionObesity in rabbits has myriad consequences, including osteoarthritis, pododermatitis, hepatic lipidosis, atherosclerosis, insulin resistance, and increased risk of postanesthetic complications. Obesity in pet rabbits can be practically diagnosed with body condition scoring, but validation is needed. Prevention of obesity should be prioritized before treatment, but both involve facilitating more exercise, limiting concentrated calorie intake, and offering plenty of hay to pet rabbits.     

Cutaneous Lymphomas in European Pet Rabbits (Oryctolagus cuniculus)

Cutaneous lymphoma is a common skin neoplasm of pet rabbits in Europe but is rarely reported in pet rabbits in North America. These neoplasms have not been previously characterized, nor has the cause for the apparent predilection for cutaneous lymphoma in European pet rabbits compared with North American pet rabbits been investigated. In this retrospective study, the authors morphologically and immunohistochemically characterized 25 cutaneous lymphomas in European pet rabbits according to the World Health Organization classification. Tumors were classified as diffuse large B cell lymphomas, with 14 lymphomas exhibiting a centroblastic/centrocytic subtype and 11 tumors exhibiting a T cell-rich B cell subtype. To investigate a potential viral etiology of these lymphomas, 3 diffuse large B cell and 3?T cell-rich B cell lymphomas were evaluated by polymerase chain reaction for retroviral and herpesviral genes. Neither virus was detected. In contrast to other domestic animals, cutaneous lymphomas in European pet rabbits were highly pleomorphic and frequently contained multinucleated giant cells. Unexpectedly, the second most common subtype was T cell-rich B cell lymphoma, a subtype that is rare in species other than horses. Based on a limited number of samples, there was no support for a viral etiology that would explain the higher incidence of lymphoma in European pet rabbits compared with American pet rabbits. Further investigation into genetic and extrinsic factors associated with the development of these tumors is warranted.     

Ophthalmic Disorders Observed in Pet Chinchillas (Chinchilla lanigera)

This article presents a retrospective analysis of ocular disorders observed in outpatient pet chinchillas examined in a veterinary clinic between 2000 and 2010. The most common ophthalmic conditions diagnosed during this time period was alteration of the lens (15 eyes, 10 chinchillas), followed by abnormalities of the cornea (14 eyes, 13 chinchillas), and conjunctival disease (10 eyes, 9 chinchillas). The predominant lens disorder was cataracts, whereas the main alteration of the cornea was fluorescein-positive corneal substance loss. Subtle ocular changes appear to be common in the chinchilla. The data gathered within this study indicate that a thorough ophthalmic evaluation is warranted during routine physical examinations for this species.     

First insight into Encephalitozoon cuniculi infection in laboratory and pet rabbits in Iran

Encephalitozoon cuniculi infects a wide variety of domestic and wild mammalian species including humans. Although the infection status has been studied in laboratory and pet rabbits worldwide, there is shortage of information regarding the disease in Iran. In the present study, the occurrence of infection in brains of 117 asymptomatic rabbits from six breeding and experimental units with highest population of rabbit colonies in the country (n = 60) as well as pet rabbits of pet stores in two cities (n = 57) were examined by nested-PCR. Histological sections of brains and kidneys were also studied by light microscopy. PCR results revealed that 3.3% of laboratory rabbits (2/60) and 59.6% of pet rabbits (34/57) harboured E. cuniculi in their brains. Histopathology on the other hand showed spores of the parasite in kidney and brain of one and kidney of another pet rabbit. As encephalitozoonosis may interfere with results of experiments performed on laboratory rabbits, routine screenings for identification and culling of infected animals is recommended. Furthermore, infected companion rabbits can transmit E. cuniculi to people in close contact with them, therefore, improving public knowledge of this zoonotic infection is suggested.     

Acute Phase Protein Levels in Rabbits with Suspected Encephalitozoon cuniculi Infection

The objective of this study was to evaluate the application of acute phase protein assays for C-reactive protein (CRP), haptoglobin (HP), and serum amyloid A (SAA) in the diagnosis of Encephalitozoon cuniculi (ECUN) infection in pet rabbits. Serum samples from 48 pet rabbits were submitted from veterinary clinics within the United States. Participating veterinarians completed a questionnaire that was used to classify rabbits as either non-ECUN suspect (n = 19) or suspected of having ECUN infection (n = 29). A previously described enzyme-linked immunosorbent assay diagnostic test was used to detect immunoglobulin G (IgG) titers against ECUN. Samples were additionally tested for levels of CRP, HP, and SAA. A nearly 10-fold mean increase in CRP levels was observed in the ECUN-suspect group. This increase was significant (P < 0.05). There was no significant difference in HP or SAA levels between the clinical groups. These data support the use of CRP as an adjunct test in the diagnosis of ECUN infection in pet rabbits.     

Age at death and cause of death of pet rabbits (Oryctolagus cuniculus) seen at an exotic animal clinic in Tokyo,Japan: a retrospective study of 898 cases (2006–2020)

BackgroundAs the quality of care received by pet rabbits improves, the age at death of these animals is expected to increase; however, reliable data on the age at death of pet rabbits is lacking. The present retrospective study aims to clarify the age at death and cause of death of pet rabbits.Materials and MethodsThe age at death, cause of death, and clinical details of 898 rabbits that died between 2006 and 2020 were obtained by reviewing paper-based medical records, including necropsy and/or biopsy reports, at a referral exotic animal hospital in Japan.ResultsThe median age at death in the 898 rabbits was 7 years (interquartile range: 5to9 years), and 18% of all rabbits lived beyond 9 years. The main causes of death included neoplasia (n = 223; 24.8%), gastrointestinal disease (n = 135; 15.0%), bacterial abscess (n = 90; 10.0%), urinary disease (n = 85; 9.5%), trauma (n = 44; 4.9%), and cardiac disease (n = 27; 3.0%). Gastrointestinal disease was the most common cause of death in younger-aged rabbits (4 years or less), while neoplasia was the most common cause of death in the middle to older-aged rabbits (5 years or more).Clinical significanceThis is one of the largest retrospective studies on the age at death in pet rabbits conducted to date; thus, the findings will serve as a useful reference for veterinarians working with such rabbits. Nevertheless, additional studies are needed to elucidate differences in the age at death of rabbits according to sex and neutering status.     

Coxofemoral luxation in pet rabbits: nine cases

Of the pet rabbits presented at one private practice between August 2011 and August 2016 (n=1369), 5·6% presented with a traumatic orthopaedic injury. Of these, 7·8% (n=6) presented with traumatic coxofemoral luxation, the most frequently observed type of luxation. Three cases of non‐traumatic coxofemoral luxation in pet rabbits are also discussed. Eight rabbits presented with craniodorsal luxation and one with caudoventral luxation. Five rabbits were initially treated using closed reduction and an Ehmer sling under sedation. Two rabbits responded satisfactorily to closed reduction; their bandages remained in place for 10 and 14 days, and movement was cage‐limited for 1 month after bandage placement. The bandage did not prevent re‐luxation in three cases. Therefore, two rabbits received iliofemoral nylon sutures, and three rabbits received a femoral neck and head ostectomy. One rabbit was treated directly using open reduction and an iliofemoral nylon suture due to fractures in the same limb. One rabbit was presented in shock, coxofemoral luxation was noticed as an incidental finding and euthanasia was elected by the owner. In conclusion, of the three rabbits treated via femoral neck and head ostectomy one rabbit had an unsatisfactory outcome and two rabbits have non‐assessable outcomes. The three rabbits treated with iliofemoral sutures showed satisfactory long‐term outcomes and the two rabbits treated with closed reduction and an Ehmer sling showed satisfactory medium and long‐term outcomes.     

Evaluation of the Rabbit Urinary Tract

Urinary tract disease is not an uncommon presentation for pet rabbits. It is beneficial for the veterinarian treating these patients to have a thorough understanding of a rabbit's urogenital anatomy, renal physiology, and diseases that affect the kidney and urinary tract. The evaluation of the rabbit urinary tract requires a multidisciplinary approach including the procurement of a thorough history, signalment, assessment of clinical signs, physical examination, and diagnostic test results. To obtain a definitive disease diagnosis, more intensive diagnostic testing may be required, including contrast radiography, ultrasound evaluation, and histopathological assessment of biopsy samples. This article will provide information to aid in the diagnosis and treatment of rabbit urinary tract diseases.     

Survey of the husbandry, health and welfare of 102 pet rabbits

One hundred and two pet rabbits were examined and their husbandry, health and welfare were reviewed. The most common breed was the dwarf lop (n = 38). The most common problem was dental disease, which affected 30 rabbits although only six of their owners were aware of the problem, which was significantly associated with feeding a rabbit mix. All the rabbits were housed in ;hutches' at some stage, but 89 had access to the outside and 47 came inside the home at times. Hutches bought at pet shops were significantly smaller than home-made hutches. Forty-five of the rabbits were housed alone; the relationships between rabbits with rabbit companions were described by their owners as ;very friendly' for 84 per cent of them and ;quite friendly' for the rest.     

Cutaneous squamous cell carcinomas in domestic rabbits (Oryctolagus cuniculus): 39 cases (1998-2019)

BackgroundDomestic rabbits (Oryctolagus cuniculi) can develop a variety of cutaneous neoplasms, including squamous cell carcinoma (SCC). A detailed review of gross and microscopic pathology and response to treatment of spontaneously arising SCCs in domestic rabbits has not been published.MethodsA retrospective survey study of the clinical characteristics and response to treatment in 39 cases of spontaneous SCC in pet rabbits was performed in an attempt to better characterize the typical presentation, prognosis, and therapeutic response of SCCs in domestic rabbits. Sixteen of these cases were also selected for papillomavirus testing using a generic polymerase chain reaction.ResultsSCC was identified in rabbits between 2 and 10 years of age, with a median age of 7 years. The neoplasm has a predilection for ears and feet and the conventional subtype is most commonly diagnosed microscopically. Lighter colored rabbits may be predisposed to developing SCC. The majority of cases examined were found in rabbits housed primarily indoors. Only one SCC tested positive for papillomavirus and was located in the oral cavity. Sequencing of the detected PCR product detected 98.75% similarity to human papillomavirus type 120. The significance of this virus for tumorigenesis is unknown.Conclusions and clinical relevanceAggressive surgical resection provided the most successful therapeutic option and proved curative in 12 of 23 rabbits. Papillomavirus likely does not play a major role in the development of spontaneous SCCs in pet rabbits. More research is needed to investigate the use of adjunctive therapies in treatment of this neoplasm in pet rabbits.     

Food and water intake and selective feeding in rabbits on four feeding regimes

Diet plays an important role in maintaining rabbit health. Feeding an incorrect diet, particularly a low fibre diet, has been linked with digestive, dental and urinary tract disease. However, food intake and dietary requirements have been poorly studied in pet rabbits. This study assessed the effects of two commonly fed pet rabbit diets [extruded nuggets with hay (EH) and muesli with hay (MH)] alongside hay only (HO) and muesli only (MO) on food and water intake in 32 Dutch rabbits. Dry matter (DM) intake was greater in the HO group and lower in the MO group than in the EH and MH groups (p < 0.001). The portion of the diet made of hay was greater in the EH group than in the MH group (p < 0.001). Water intake was positively correlated with DM intake and was greatest in the HO group (p < 0.001). Selective feeding occurred in all rabbit groups fed muesli, whether or not hay was also available. Pellets were rejected, and grains and extrudates selected. The presence of selective feeding in all rabbits fed muesli leads to the consumption of an unbalanced diet. In addition, hay intake and water intake were lower when muesli was fed. Conclusions drawn from this study are based on general recommendations for pet rabbits, and clinical disease may have developed by feeding the study diets over a longer time period, as many diet‐related conditions typically present in older rabbits. However, the study demonstrates that the feeding of muesli diets cannot be recommended.     

Lead-induced toxicosis in two domestic rabbits

Lead toxicosis developed in 2 pet rabbits. Both rabbits had decreased appetite or anorexia; also, one had mild anemia and one had pleural effusion. Treatment with the calcium chelate of ethylenediaminetetraacetic acid was effective in both rabbits. The rabbit's propensity for gnawing may result in lead toxicosis, and may be seen more frequently as rabbits become more popular as pets.     

Urgent care of the pet rabbit.

Emergency and critical care principles are similar for all mammals; however, the physiology and natural behavior of rabbits create an animal that is easily stressed and requires specialized handling techniques. This article reviews diagnostic and therapeutic techniques, nutritional support, and pain management for urgent care of pet rabbits. Common differential diagnoses for emergencies are briefly reviewed by the clinical presentation. A table of drug dosages used for urgent care is provided.     

Cryptosporidium infection in juvenile pet rabbits

Cryptosporidium infection was confirmed by fecal examination for the first time in pet rabbits in a wholesale store located in Kanagawa Prefecture, Japan. Fecal samples were obtained postmortem from juvenile rabbits (n=66), which had died after developing diarrhea. Feces from healthy rabbits (n=30) were also collected and examined as controls. Two types of Cryptosporidium oocysts distinctive in size and shape were found (Type A and B). Types A and B oocysts were detected from 16.7% and 13.6% of the diarrheic, and 3.3% and 0% of the normal feces, respectively. Since Cryptosporidium oocysts were detected at a higher rate in the diarrheic rabbits than in the healthy rabbits, special caution should be taken when handling a pet rabbit presenting with diarrhea.     

Surgical resolution of uterine prolapse in three pet rabbits

This report describes a surgical technique for resolution of uterine prolapse in rabbits. Three pet rabbits presented within 24 hours of parturition with a red mass protruding from the vagina, which was diagnosed as uterine prolapse. In the first case, an attempt to reduce the prolapse by manual compression was ineffective. A laparotomy was used to apply internal uterine traction while simultaneously using gentle external pressure with cotton-tip applicators and resulted in successful resolution. After repositioning, an ovariohysterovaginectomy was performed in all three rabbits. All rabbits recovered uneventfully. Laparotomic repositioning of the uterus and ovariohysterovaginectomy, not previously described in rabbits, was easy to perform and permitted resolution of uterine prolapse.     

Nerve Stimulator–Guided Sciatic-Femoral Block in Pet Rabbits (Oryctolagus cuniculus) Undergoing Hind Limb Surgery: A Case Series

This article describes the clinical applicability of a nerve stimulator–guided technique, previously described in dogs, to block the sciatic and the femoral nerves in 4 pet rabbits (Oryctolagus cuniculus) undergoing hind limb surgeries. Preanesthetic intramuscular doses of medetomidine (0.08 mg/kg), ketamine (15 mg/kg), and buprenorphine (0.03 mg/kg) were administered to the rabbit patients. The rabbits were intubated and general anesthesia was maintained using isoflurane in oxygen. The sciatic-femoral nerve block was performed with 2% lidocaine at a volume of 0.05 mL/kg/nerve. Sciatic-femoral block was feasible in rabbits, and the motoric responses following electrical stimulation of both nerves were consistent with those reported in dogs after successful nerve location. Iatrogenic complications, namely nerve damage and local anesthetic toxicity, did not occur. Based on these results, the authors conclude that the sciatic-femoral nerve block described in dogs can be safely performed in rabbits. Clinical trials are required to assess the analgesic efficacy of the combined sciatic-femoral nerve block in rabbits as a part of multimodal pain management.