Surgical and localized radiation therapy for an intranasal adenocarcinoma in a rabbit

Neoplastic and non-neoplastic lesions in biopsy samples from pet rabbits in Hong Kong: a retrospective analysis, 2019-2022

Rabbits are popular pets in the urban environment of Hong Kong, ranking third behind cats and dogs. Here we describe the frequency of neoplastic and non-neoplastic lesions in biopsies from pet rabbits submitted to the CityU Veterinary Diagnostic Laboratory between 2019 and 2022, comprising 247 tissue samples from 243 rabbits collected by veterinarians in 19 veterinary clinics. Among the 243 rabbits, there were 128 females (65 spayed), 114 males (54 castrated); sex information was not provided for 1 rabbit. The rabbit breeds included 45 Lionhead, 35 Dwarf, 14 Lop, 11 Dwarf Lop, 5 French Lop, 3 Angora, 2 Dutch, 2 Holland Lop, and 1 each of Netherland Dwarf, Velveteen, Mini Lop, and New Zealand White. The mean ages of rabbits with neoplastic and non-neoplastic lesions were 7.1 and 5.7 y, respectively. The most common neoplastic lesions were adenocarcinoma (26.4%), trichoblastoma (21.4%), sarcoma (9.4%), and thymoma (8.2%). The most common non-neoplastic lesion was uterine cystic endometrial hyperplasia (14.8%), followed by dermal abscess formation in the ventral abdomen or skin of the head (12.5%). Although a broad spectrum of other lesions was described, our findings in biopsies from pet rabbits in Hong Kong are consistent with those in other jurisdictions.

Respiratory Disorders in Rabbits

Respiratory disorders are very common in rabbits. Rabbits are obligate nasal breathers, so "simple" rhinitis can cause severe respiratory distress and patient collapse. Causes of dyspnea could be of primary origin or secondary, whereby diseases primarily affecting other organs can result in respiratory embarrassment even if the respiratory system is healthy (eg, anemia, cardiac disease). Diagnosis is based on radiography, ultrasonography, endoscopy, computed tomography, and/or pathogen isolation. Once the diagnosis has been completed, treatment options should be discussed with the owner. The article describes the anatomy of the respiratory tract, diagnostics, and therapy for selected respiratory disorders in rabbits.

Spontaneous intranasal tumours in rabbits: 7 cases (2007-2019)

OBJECTIVES

Neoplasms that arise in the nasal cavity are reported infrequently in rabbits. This case series aims to review and determine the clinical behaviour of neoplasms in the nasal cavity in rabbits.

MATERIALS AND METHODS

A retrospective study was conducted on seven pet rabbits diagnosed with intranasal tumours to describe the clinical and histopathological findings and prognoses after surgery and/or radiotherapy.

RESULTS

The most common clinical signs were nasal snoring when breathing, nasal discharge, and subsequent dyspnoea and anorexia. Six different histopathological types of tumours were diagnosed: intranasal adenocarcinoma, squamous cell carcinoma, osteosarcoma, carcinoid tumour, osteoma, and lymphoma. Skull radiography only revealed the abnormalities in three of seven cases but on CT, the intranasal masses were more clearly identified in all cases. All cases received tumour resection through rhinostomy and four cases received radiotherapy after surgery. In the six cases with a known outcome, the survival time after surgery was more than 13 months.

CLINICAL SIGNIFICANCE

This case series provides an insight of the behavior of intranasal neoplasms in rabbits. Surgical treatment and radiotherapy could improve their clinical sings.

Update on Cancer Treatment in Exotics

Treatment options for animals with cancer are rapidly expanding, including in exotic animal medicine. Limited information is available about treatment effects in exotic pet species beyond individual case reports. Most cancer treatment protocols in exotic animals are extrapolated from those described in humans, dogs, and cats. This review provides an update on cancer treatment in exotic animal species. The Exotic Species Cancer Research Alliance accumulates clinical cases in a central location with standardized clinical information, with resources to help clinicians find and enter their cases for the collective good of exotic clinicians and their patients.

Lateral rhinostomy for treatment of severe chronic rhinosinusitis in two rabbits

CASE DESCRIPTION 2 client-owned rabbits were evaluated for signs of chronic upper respiratory tract disease. CLINICAL FINDINGS Clinical signs had been present for 3 weeks and 4 years and included mucopurulent nasal discharge, right-sided maxillary swelling, recurrent dacryocystitis, and intermittent sneezing. One rabbit had been treated with nasolacrimal duct lavage and topical and systemic antimicrobial administration without resolution of clinical signs. Results of CT of the head in both cases indicated severe rhinosinusitis. TREATMENT AND OUTCOME Both rabbits underwent unilateral rhinostomy by means of a lateral approach. Access was established via the facies cribrosa of the maxillary bone. Purulent material was removed from the affected nasal cavity and the maxillary sinus by means of debridement and lavage. After endoscopic exploration, marsupialization was performed to create a stoma. Both rabbits recovered from surgery without apparent complications, and the surgical site healed within 1 month in both. Computed tomography was repeated 5 months after surgery in one rabbit and 13 months after surgery in the other and indicated patent nasal passages and no evidence of recurrence or persistence of disease. CLINICAL RELEVANCE Results suggested that lateral rhinostomy should be considered for treatment of chronic severe rhinosinusitis in rabbits. Such an approach may be less technically demanding and could decrease the likelihood of postsurgical complications reported with other techniques.

Rabbit Oncology: Diseases, Diagnostics, and Therapeutics

Neoplasia has long been reported as a rare finding in rabbits, but over the past decades the number of reports on neoplastic disease in rabbits has risen considerably. Similar to other animals, neoplastic changes may occur in any organ system, but the rate in which the organ systems are affected differs considerably. In rabbits, tumors have predominantly been found in the urogenital, hemolymphatic, and integumentary systems. This article discusses current insights on the etiopathogenesis, clinical signs, diagnosis, and treatment of the commonest neoplastic diseases in rabbits and offer guidelines for the correct diagnosis and treatment of the rabbit oncologic patient.

Principles and Applications of Radiation Therapy in Exotic Animals

Radiation therapy is a treatment modality for cancer that is widely used in veterinary medicine, although its use in exotic animal practice has remained limited. However, there are case reports and case series of treating birds, small mammals, and reptiles for a variety of cancers with radiotherapy with varied outcomes. In this article the basic principles of radiation therapy are reviewed and the literature regarding its use in exotic animal practice is summarized. Side effects of radiotherapy are also discussed.