Tuberculosis in a rabbit: A case revisited

Extract

There has been only one reported case of tuberculosis caused by Mycobacterium bovis in a free-living wild rabbit, Oryctolagus cuniculus cuniculus ⁽¹⁾. Because of continued interest in that case, the common classification of rabbits and hares in the family Leporidae and a current report of a case in a hare⁽²⁾, this opportunity is taken to re-record the case in the rabbit in greater detail.     

A case of combined hermaphroditism and autofertilisation in a domestic rabbit

A true hermaphrodite rabbit served several females and sired more than 250 young of both sexes. In the next breeding season the rabbit, which was housed in isolation, became pregnant and delivered seven healthy young of both sexes. It was kept in isolation and when autopsied was again pregnant and demonstrated two functional ovaries and two infertile testes. A chromosome preparation revealed a diploid number of autosomes and two sex chromosomes of uncertain configuration.     

Melanotic neurofibroma in a steer

A melanotic neurofibroma in a steer was investigated histologically, immunohistochemically and ultrastructurally. A very large tumor mass was located in the region of the head and right cheek. The tumor tissue consisted of an admixture of cells resembling Schwann cells and spindle-shaped cells, and they frequently contained melanin granules. Neoplastic Schwann cells were positive for S100 protein, with variation in intensity of staining, but most spindled cells were S100 negative. The tumor cells displayed ultrastructural features similar to those of Schwann cells or perineurial cells. The presence of melanosomes in varying stages of melanization in both cell types suggests that they have a common origin. This is a tumor of neural crest origin showing schwannian and perineurial differentiation, with ectopic production of melanin granules.     

Cytogenetic studies in a canine neurofibroma

An 11-year-old German shepherd bitch developed a neurofibroma in the right shank. On cytogenetic analysis of the tumour cells 90% presented themselves with trisomy 2, a derivative chromosome 13 (der13) and centric fusions 10/35 and 24/31.     

Recurrent bilateral exophthalmos associated with metastatic thymic carcinoma in a pet rabbit

A five-year-old, castrated, male chinchilla rabbit was presented for evaluation of recurrent bilateral exophthalmos. Besides a transient and stress-related exophthalmos with protrusion of both third eyelids, the ophthalmological examination was unremarkable. Plain radiography of the thorax revealed a large precardial mass of soft tissue density. Cytological preparations from the thoracic mass were dominated by small, mature lymphocytes with approximately 10 to 20 per cent lymphoblasts. Computed tomography of the head showed a symmetrical laterodorsal deviation of both eyes without evidence of retrobulbar masses. On necropsy a large cystic mass was present in the cranial thorax associated with severe hydrothorax, hydropericardium and ascites. Histology identified the precardial mass as thymic carcinoma with metastases in the kidneys. This case illustrates the difficulty of diagnosing thymic tumours based on cytological or histological features of the primary tumour alone. To the authors' knowledge, this is the first case of recurrent bilateral exophthalmos associated with a metastatic thymic carcinoma in a pet rabbit.     

A case of lymphoma developing in the rabbit cecum

A rare lymphoma that developed in the cecum of a domestic pet rabbit (6 years old, male, crossbred) was examined pathologically. The tumor consisted of proliferating neoplastic lymphoid cells, which were strongly stained with anti-CD79alpha monoclonal antibody. Electron microscopy revealed the tumor cells were composed of rough endoplasmic reticula and/or dilated rough endoplasmic reticula filled with moderately electron-dense material. These findings indicated the present case was rare digestive tract lymphoma originated from B-lymphocytic lineage in the cecum.     

Use of collagen shields for treatment of chronic bilateral corneal ulcers in a pet rabbit

A four-year-old, 1·3-kg entire male Holland Lop pet rabbit (Oryctolagus cuniculus) was presented with a two-day history of bilateral epiphora and blepharospasm. Fluorescein staining revealed bilateral medio-ventral corneal ulceration. Initial topical treatment included ophthalmic broad-spectrum antibiotics and artificial tear solutions. Over a six-month period, antibiotics were changed based on corneal culture and sensitivity test results, and periodic corneal debridement was performed. With little to no improvement, and recurrence of the previous clinical signs, surgical intervention was considered but withheld because of individual pet consideration and owner's reluctance. Hydrophilic contact lenses were placed for corneal support but failed and caused a severe ocular response. Corneal collagen shields were placed bilaterally in order to promote corneal healing. Recheck examination performed seven days after placement revealed complete resolution of the ulcer in one eye and major reduction of the corneal ulcer in the contra-lateral eye.     

Hyperostotic polyarthropathy in a rabbit - a suspected case of chronic hypervitaminosis A from a diet of carrots

Chronic hypervitaminosis A can occur in many species after excessive dietary intake of Vitamin A (retinol). The most common presentation of chronic hypervitaminosis A is a polyarthropathy with hyperostosis and ankylosis of various joints. This case report describes a probable case of naturally occurring hypervitaminosis A-induced polyarthropathy in a rabbit after chronic ingestion of a diet made up almost exclusively of carrots. Carrots do not contain retinol, but are rich in provitamin A (or beta-carotene). Rabbits are unique in that they can convert 100% of dietary beta-carotene into retinol. A syndrome of naturally occurring hypervitaminosis A-induced polyarthropathy has not been described in a rabbit before.     

Surgical correction of aberrant conjunctival overgrowth in a rabbit: a case report

A dwarf rabbit presented with unilateral aberrant conjunctival growth. Allgoewer’s U-suture therapy was initially used to correct the overgrowth. Centrifugal incisions extending up to the limbus were made on the hypertrophic conjunctiva. Transpalpebral limbal fixation was performed next. When the symptoms recurred 3 weeks later, a second operation was performed using the Lembert suture method instead. The overgrowing membrane was excised radically just posterior to the limbus. The conjunctiva was then sutured using the Lembert pattern. The rabbit recovered with no further complications.     

A case of adenocarcinoma of the endometrium extending into the leiomyoma of the uterus in a rabbit

In a pet rabbit, 2 tumor masses one on each horn were macroscopically seen in the wall of the uterus. On light microscopic examination, the right horn mass consisted of an admixture of neoplastic epithelial and mesenchymal element. The epithelial element was composed of neoplastic epithelial cells with numerous mitotic figures and formed varied sizes of acini, glandular, and solid structures. The tumor was diagnosed as an adenocarcinoma of the endometrium. The mesenchymal element was composed of well-differentiated smooth muscle cells and was diagnosed as a leiomyoma. While adenocarcinoma cells formed a protrusive mass in the uterine lumen, they also showed an extension into the leiomyoma of the myometrium. By immunohistochemistry, adenocarcinoma stained positive for cytokeratin (MNF116) and leiomyoma stained positive for smooth muscle actin, showing a substantial difference in the cytological nature of these tumor cells. The results may give a further evidence supporting the narrative of the tumor development that an adenocarcinoma of the endometrium extended into leiomyoma of the uterus. To the author's knowledge, this is the first report describing this type of combination of two independent tumors in a pet rabbit.     

一起獭兔囊尾蚴病的诊治报告

本文结合实际病例介绍了獭兔囊虫病的发病情况、临床症状、剖检变化以及实验室检查方法,并提出了有效的治疗措施和预防方法.     

Tibial aplasia and agenesis in a rabbit (case report)]

The occurrence of a tibial aplasia (left side) and agenesia (right side) in a rabbit (aged 4 weeks) is reported. Apart from extreme distorsions of the fibular bones, there were no other skeletal malformations.