[Extraction of diseased mandibular incisors in the guinea pig (Cavia porcellus) via ventral mandibular trepanation]. / Extraktion erkrankter Unterkieferinzisivi beim Meerschweinchen (Cavia porcellus) via ventraler Mandibulatrepanation.

OBJECTIVE: This retrospective study describes the use of ventral mandibular trepanation for extraction of diseased mandibular incisors in guinea pigs and evaluates the clinical outcome. MATERIAL AND METHODS: In 40 guinea pigs with abnormal feed intake, at least one mandibular incisor was extracted via ventral mandibular trepanation. The diagnosis of primary mandibular incisor disease was based on the findings of the clinical general examination and intraoral and radiographic examination under general anesthesia. Following the procedure radiographs were taken and the patients were monitored and cared for as inpatients until discharge. Regular re-examinations were undertaken in order to assess and treat the surgical sites. RESULTS: A total of 42 altered mandibular incisors were extracted via ventral mandibular trepanation. Macrodonts (25/42) and periapical and alveolar changes (8/42) were the main reasons for extraction. Tooth residuals of unknown etiology (4/42) as well as such resulting from failed conventional extraction attempt using luxators (3/42) and traumatically loosened incisors (2/42) were also extracted. Tooth-associated jaw abscesses were found in 40 % of the guinea pigs. In addition, 40 % of the animals presented secondary elongation of the molars requiring occlusal equilibration. In all patients, it was possible to completely remove the altered incisors or residuals. On average, independent feed intake was observed 2 days after surgery and the animals were discharged. Complete healing of the surgical site was observed on average after 39 days (minimum 9 days, maximum 98 days). A total of 22 animals were evaluated 6 months following surgery and showed no further tooth-associated complaints. CONCLUSION AND CLINICAL RELEVANCE: Ventral mandibular trepanation allows diseased mandibular incisors in guinea pigs to be removed entirely within one surgery and thus represents a curative procedure. Unlike the conventional extraction with luxators, it does not bear the risk of tooth fractures resulting in tooth fragments remaining in the alveolus.

Amelanotic Malignant Melanoma in a Himalayan Rex Guinea Pig (Cavia porcellus).

A Himalayan Rex guinea pig was presented with a history of nodular, partially ulcerated masses in the subcutis of the left shoulder. Histological examination revealed a garland-like to nodular, infiltrative neoplastic mass of the epidermis and hair follicle epithelium, which obscured the dermoepidermal junction. Neoplastic cells were immunopositive for S100, PNL-2, vimentin and melan-A antigens. No immunolabelling of CD3, CD79, Iba-1 or pancytokeratin was observed. This is the first detailed description of spontaneous amelanotic malignant melanoma in this species.

Validation of whole-body radiographs for examining uterine disorders in sexually intact female rabbits.

OBJECTIVE: The present study evaluated whole-body radiographs of female rabbits regarding uterine disorders. MATERIAL AND METHODS: Based on radiographs of 143 rabbits, visibility, size, shape and density of the uterus, nutritional status of the animal and possible metastasis in other organs were examined. A suspected diagnosis was deduced. The radiological findings were compared with the results of the histopathological examination. RESULTS: Especially the nutritional status was important regarding the visibility of the genital tract. In 99 of the 130 visible uteri (76.2 %), a pathological alteration was detected. Thereof, endometrial hyperplasia was most frequently seen (63.6 %), followed by neoplasia (altogether 42.4 %, 39.4 % of these with adenocarcinoma), endometritis (35.4 %) and other diseases (18.2 %). Forty-six rabbits showed only one disease, 42 rabbits had two, 10 rabbits three and one rabbit four different diseases. Among 13 of the 143 uteri that were not visible in the radiograph four were altered pathologically. In 31 of the 130 rabbits with a visible uterine region (21.7 %) the uterus was unaltered. Visualising the uterus proved impossible in two of four skinny rabbits (2.8 %), whereas in all 39 obese rabbits the uterus was visible. Only in one of the four skinny rabbits was the uterus without pathological findings and six of the 39 obese rabbits showed no pathological alteration, visibility notwithstanding. Calcification indicated a tumourous occurrence in 23 of 53 cases. Except for one rabbit, the mineralised neoplasia was an adenocarcinoma (n = 22). Five animals with calcification in the uterine region showed no abnormalities. Of these, the calcification of four animals was no longer existent in the radiograph after ovariohysterectomy. Neoplastic changes in the uterus did not always show calcification. In 20 of the 44 patients with uterine neoplasia no calcification was seen. Changes in uterine size occurred in 118 of the 143 rabbits (82.5 %) and alteration of the uterine shape in 109 of the 143 rabbits (67.1 %). CONCLUSION AND CLINICAL RELEVANCE: Thus, the above presented parameters - especially size, shape and mineralisation - are very important regarding uterine diseases.

[Oligodendroglioma with neuronal differentiation in an 8-month-old African hedgehog (Atelerix albiventris)]. / Oligodendrogliom mit neuronaler Differenzierung bei einem 8 Monate alten Afrikanischen Weißbauchigel (Atelerix albiventris).

An 8-month-old, male African hedgehog clinically displayed a wobbly walk, anuria, inappetence and apathy, whereupon the suspected diagnosis wobbly hedgehog syndrome was made. After exacerbation, the hedgehog was euthanized. Histologically, a tumour mainly consisting of medium-sized, oval tumour cells and a smaller number of spindeloid cells was found in the cerebrum. The tumour contained neuropil islets and extracellular myxoid material. Immunohistochemically, the tumour cells expressed oligodendroglial (neurite outgrowth inhibitor, Nogo-A; oligodendrocyte transcription factor, Olig-2) and neuronal (neuron-specific enolase, NSE; microtubule-associated protein-2a, MAP-2a; synaptophysin) cell markers. Based on these findings, an oligodendroglioma with neuronal differentiation was diagnosed. Such a brain tumour has to date not been reported for African hedgehogs. At necropsy, a severely filled and dilated urinary bladder was observed, which was presumably caused by a central blockade of the micturition centre in the brain. In the case of neurological symptoms in young hedgehogs, a primary brain tumour should, as in adults, be considered as a differential diagnosis. As further differentials, inflammatory-infectious (rabies, herpes, baylisascariosis), degenerative (cardiomyopathy, intervertebral-disc disease), traumatic, alimentary (vitamin-B deficiency) and metabolic-toxic (heat-cold-torpor, hepatic encephalopathy) triggers have to be considered.