Evaluation of a genetic assay for canine transmissible venereal tumour diagnosis in Brazil

The canine transmissible venereal tumour (CTVT) is a transmissible cancer that is spread between dogs by the allogeneic transfer of living cancer cells. The infectious agents in CTVT are the living cancer cells themselves, which are transmitted between dogs during coitus. CTVT first arose several thousand years ago and the disease has a global distribution and is frequently observed in dogs from Brazil. We evaluated the utility of a LINE‐MYC quantitative polymerase chain reaction for diagnosis of CTVT cases in Brazil. Our analysis indicated that the LINE‐MYC rearrangement was detectable in all CTVT samples but not in their corresponding hosts. This genetic assay proves to be a useful tool for providing a definitive molecular diagnosis of CTVT, which presents with varying degrees of aggressiveness and invasiveness in different host dogs and can therefore be a diagnostic challenge in some specific cases.     

Extragenital transmissible venereal tumour associated with circulating neoplastic cells in an immunologically compromised dog

An adult male intact boxer was presented because of diffuse cutaneous nodules. Fine‐needle aspirate revealed transmissible venereal tumour (TVT) cells. Neoplastic cells were also observed in the peripheral blood. Associated simultaneous diseases included leishmaniosis, demodicosis, papillomatosis and coccidiosis. Immunosuppression may have aggravated disease and triggered widespread metastases. The dog was hospitalized and administered oral amoxicillin/clavulanate, subcutaneous meglumine antimonite to treat leishmaniosis and oral chlortetracycline to treat coccidiosis. Intravenous injection of vincristine at weekly interval was used to treat TVT. A rapid regression of cutaneous nodules was noted; however, intractable diarrhoea developed, eventually leading to death after 18 days. This is the first report describing an unusual case of extragenital TVT associated with circulating neoplastic cells in an immunosuppressed dog presenting with multiple cutaneous nodules.     

Ocular involvement of transmissible venereal tumor in a dog

A case of metastatic transmissible venereal tumor (TVT), with lesions on the penis, conjunctiva, buccal mucosa and skin (lips and trunk), is presented in this case report. The clinical picture is described along with the cytological and histopathological features of the tumor leading to definitive diagnosis of TVT. Possible reasons for the unusual metastatic behavior of TVT and full recovery of the dog after chemotherapy are discussed.     

Immunohistochemical characterization of intraocular metastasis of a canine transmissible venereal tumor

Little has been published on intraocular metastasis of transmissible venereal tumors (TVT) in dogs. This report presents a 4-year-old male Labrador Retriever with a previous history of subcutaneous TVT which underwent total remission after treatment with vincristine. The dog presented with clinical signs of uveitis and increased intraocular pressure (IOP) in both eyes. After enucleation of the left eye, a diagnosis of TVT was made based on morphology, histology and immunohistochemistry (IHC). IHC staining for vimentin, S-100 protein, cytokeratin and HMB45 was performed to differentiate this lesion from TVT, lymphoma, melanoma, carcinomas, neurogenic tumors and fibrosarcoma. The IHC findings supported the diagnosis of TVT for this round cell tumor.     

Canine Transmissible Venereal Tumour: Asessment of Mast Cell Numbers as Indicators of the Growth Phase

Mast cells are immune cells that are involved mainly in type 1 hypersensitivity reactions, and they have been implicated in tumour angiogenesis. In this study we assessed the presence of mast cell numbers and microvessel density during the progression and regression stages of natural spontaneous canine transmissible venereal tumours (CTVT). Mast cells were demonstrated by histochemical staining with toluidine blue, alcian blue and safranin O. Microvessel counts were demonstrated by immunohistochemical labelling with an antibody against the endothelial cell marker factor VIII. Mitotic cells, apoptotic cells and tumour infiltrating lymphocytes were counted from haematoxylin–eosin-stained sections. Tumour fibrosis was evaluated on Masson's trichome-stained sections. The results showed that progressing tumours had significantly higher mast cell counts and microvessel counts at the invasive edges of the tumours than did regressing tumours. In both the progressing and regressing tumours, microvessel counts were significantly positively correlated with mast cell counts. Regressing tumours had significantly higher mast cell counts of the whole tumour than progressing tumours. The results also showed that progressing tumours had significantly higher mitotic rate than regressing tumours, and fibrosis and apoptosis were significantly higher in regressing tumours than progressing tumours. There were no significant differences between the biochemical and haematological values of dogs with progressing and regressing tumours. These results suggests that mast cells play a role in CTVT progression probably by promoting vascularization at the invasion front during the progression phase, and that mast cell count could be used as one of the histological factors to indicate growth stage of CTVT.     

Cutaneous transmissible venereal tumor without genital involvement in a prepubertal female dog

An 11-month-old prepubertal crossbreed female dog was presented with multiple nodular lesions disseminated over the cervical, back, flank, and abdominal regions. The lesions were ulcerated and cauliflowerlike, or nodular and subcutaneous, measuring up to 13 cm in diameter. Cytologic preparations of one of the lesions revealed a uniform population of round to oval cells, with lightly basophilic cytoplasm that contained multiple distinct vacuoles. Frequent mitotic figures and occasional lymphocytes were also observed. The cytologic diagnosis was cutaneous transmissible venereal tumor (TVT) in a progressing growth phase. This was confirmed by histologic and immunohistochemical findings. Vaginal TVT was diagnosed later in the dog's mother. TVT is a contagious neoplasm of sexually mature dogs that usually is transmitted by coitus and affects the genital mucosa. To our knowledge, this is the first report of naturally occurring multicentric TVT in a prepubertal female dog and also is unique in its exclusively cutaneous (no mucosal) involvement. We speculate that transmission of neoplastic cells occurred during cohabitation and social/mothering behavior between the dogs. Despite the atypical clinical presentation, response to chemotherapy with vincristine was excellent, leading to complete regression of the neoplasm without relapse after 6 months.     

Clinico-pathological studies on the effect of different anti-neoplastic chemotherapy regimens on transmissible venereal tumours in dogs

Thirty-two dogs affected with transmissible veneral tumour (TVT) were divided into three treatment groups. In group I vincristine sulphate at 0.025 mg/kg body weight, in group II vinblastine sulphate at 0.150 mg/kg body weight, and in group III vinblastine sulphate at 0.100 mg/kg body weight plus methotrexate at 0.35 mg/kg body weight were given intravenously at weekly intervals. Biopsies were performed on days 0, 3, 7 and 14. The tissues were preserved in 10% neutral buffered formalin and processed routinely for haematoxylin and eosin staining. Histopathologically, the untreated TVT was characterized by sheets or bundles of mostly rounded cells having a large, highly basophilic nucleus with a prominent, highly basophilic nucleolus. Both vincristine and vinblastine primarily affected the nuclei of neoplastic cells, causing condensation, karyorrhexis and karyolysis within 3 days of chemotherapy. The regressing tumour mass showed marked infiltration by lymphocytes, lymphoblasts and macrophages by day 7. There was nearly complete regression of the tumour by day 14, as shown by the almost complete loss of neoplastic cells, with fibrous tissue substitution. However, in group III, the changes occurred more slowly and more injections were needed for complete regression. In both groups I and II, 11/12 of the animals responded completely to the chemotherapy within 3 weeks, while in group III, 6/8 of the dogs responded to the treatment by 21–28 days.Abbreviations SD standard deviation - TVT transmissible venereal tumour     

Canine transmissible venereal tumour and ovarian papillary cystadeno-carcinoma in a bitch

A young German shepherd dog was presented for a protruding vaginal mass of one month's duration. Clinical appearance of the mass was suggestive of a canine transmissible venereal tumour. Diagnosis was confirmed by cytology; a single drug chemotherapy regimen using vincristine was instituted. Regression was evident within seven days after the first treatment. Bilateral ovarian papillary cystadenocarcinoma was an incidental finding after an elective ovariohysterectomy was performed.     

Canine transmissible venereal tumour: cytogenetic origin, immunophenotype, and immunobiology. A review

Canine transmissible venereal tumour (CTVT) is the only known naturally occurring tumour that can be transplanted as an allograft across major histocompatibility (MHC) barriers within the same species, and even to other members of the canine family, such as foxes, coyotes and wolves. The progression of this tumour is unique in that, it follows a predictable growth pattern. In natural and experimental cases, the growth pattern includes progressive growth phase, static phase and regression phase, and this is followed by transplantation immunity in immunocompetent adults, while metastasis occurs in puppies and immunosuppressed dogs. Because of the uniqueness of CTVT transmission and progression, experimental investigations of various aspects of the biology of CTVT have been used to provide clues to the immunobiology of both animal and human tumours. This review examines the current state of knowledge of the aspects of the cytogenetic origin, immunophenotype, immunobiology and immunotherapy of CTVT.     

Review of Canine Transmissible Venereal Sarcoma

Veterinary Research Communications -     

Canine Transmissible Venereal Tumour Parasitized by Leishmania infantum

Veterinary Research Communications -     

Vascular-targeted photodynamic therapy (VTP) of a canine-transmissible venereal tumour in a murine model with Pd-bacteriopheophorbide (WST09)

Treatment of canine‐transmissible venereal tumour (CTVT) with local vascular‐targeted photodynamic therapy (VTP) using Pd‐bacteriopheophorbide (WST09) as a drug is suggested as an alternative to conventional chemotherapy. Male CD1 nude mice were subcutaneously grafted with the xenograft‐transmissible canine venereal tumour (XTVT). The VTP protocol delivered once consisted of intravenous administration of WST09 (10 mg kg^?1) followed by immediate local illumination with a diode laser (763 nm). Controls included animals treated with light or WST09 alone. Macroscopic and microscopic evaluations of tumour response were conducted 10, 24 and 48 h after treatment. Upon VTP, tumours underwent necrosis that lasted 8–10 days and exhibited complete healing by 25–35 days, reaching an overall long‐term cure rate (83%) by 90 days after treatment. This study suggests that VTP with WST09 can efficiently treat CTVT in a single session, as compared with 4–6 sessions of chemotherapy and thus may be feasible for common veterinary practice, particularly under ambulatory conditions.     

Metastasis of a transmissible venereal tumour to the pituitary

This report presents a case of metastasising transmissible venereal tumour (TVT) with lesions of the penis, lip, spleen and pituitary. The clinical picture is outlined and the associated diagnostic radiographic procedures used to reach a final diagnosis of a space–occupying lesion in the region of the pituitary are described. A definitive diagnosis of a metastasizing TVT was reached by histopathological examination and it is concluded that the pituitary and spleen metastases are examples of the systemic dissemination of the original penile tumour whilst the lip lesion probably arose by direct contact.     

一例犬腹股沟疝气的诊断与治疗

腹腔脏器经腹股沟环脱出至腹股沟外侧皮下形成局限性隆起,称为腹股沟疝。2012年,接诊了1只4岁的雌性巴哥犬,临床检查结果显示左右大腿内侧各有1肿块,据检查结果初步怀疑为腹股沟疝。结合X光、B超检查和血液检查确定该犬患有腹股沟疝。在征得畜主同意后,采用手术治疗和术后综合性护理措施,愈后良好。     

Canine lymphoma: a review

Canine lymphoma (cL) is a common type of neoplasia in dogs with an estimated incidence rate of 20–100 cases per 100,000 dogs and is in many respects comparable to non-Hodgkin lymphoma in humans. Although the exact cause is unknown, environmental factors and genetic susceptibility are thought to play an important role. cL is not a single disease, and a wide variation in clinical presentations and histological subtypes is recognized. Despite this potential variation, most dogs present with generalized lymphadenopathy (multicentric form) and intermediate to high-grade lymphoma, more commonly of B-cell origin. The most common paraneoplastic sign is hypercalcemia that is associated with the T-cell immunophenotype. Chemotherapy is the treatment of choice and a doxorubicin-based multidrug protocol is currently the standard of care. A complete remission is obtained for most dogs and lasts for a median period of 7–10 months, resulting in a median survival of 10–14 months. Many prognostic factors have been reported, but stage, immunophenotype, tumor grade, and response to chemotherapy appear of particular importance. Failure to respond to chemotherapy suggests drug resistance, which can be partly attributed to the expression of drug transporters of the ABC-transporter superfamily, including P-gp and BCRP. Ultimately, most lymphomas will become drug resistant and the development of treatments aimed at reversing drug resistance or alternative treatment modalities (e.g. immunotherapy and targeted therapy) are of major importance. This review aims to summarize the relevant data on cL, as well as to provide an update of the recent literature.     

Carprofen inhibition of flare in the dog measured by laser flare photometry

The purpose of this study was to determine whether oral carprofen (Rimadyl®) treatment in dogs could prevent or decrease the breakdown of the blood–aqueous barrier. The topical pilocarpine irritative model was used to induce breakdown and cause flare. Pilocarpine was instilled in both eyes of seven dogs at time zero and again 5 h later. At 7 h, laser flare photometry was used to measure the flare concentration in each eye using the Kowa FC-1000 laser flare cell meter. All treatments were then discontinued. Two days later, carprofen was administered to the same dogs for a total of three doses. After the last dose of carprofen, pilocarpine treatments and flare measurements were repeated. Carprofen pretreatment resulted in a 68% inhibition of flare, which was highly significant ( P < 0.01). The pilocarpine group had a mean of 16.1 photon counts per millisecond (PC ms⁻¹) ± 2.2 SE, and the carprofen group had a mean of 7.0 PC/ms ± 1.2 SE. These results compare favorably with previous studies measuring increased protein or fluorescein concentrations in the aqueous humor after blood–aqueous barrier breakdown in the dog. These results suggest that carprofen may be effectively used as a systemically administered ocular anti-inflammatory drug. Carprofen has the added benefit of fewer reported side effects.     

一例犬会阴疝的诊治报告

会阴疝（perineocele）是盆隔肌组织缺陷，不能支撑直肠，使盆腔及腹腔内容物经盆膈和直肠间脱至会阴部皮下。此病在临床上发病率低，死亡率小，但病程长，诊断和治疗困难。就一例会阴疝患犬的诊断和治疗进行分析和总结，尤其对手术治疗展开深入探讨，目的是为该病的临床诊疗提供一定的理论和实践指导意义。     

一例犬子宫蓄脓的诊断及手术治疗

本试验对一例患有子宫蓄脓的西施犬通过询问病史、临床检查、血常规检测、X光及B超检查进行确诊,采用手术法治疗。结果显示,血常规检查发现白细胞、中性粒细胞均增多,X光检测到明显膨大的子宫,B超影像可观察到子宫角为圆腔状的黑色暗区,子宫壁增生变厚产生无回声液性暗区。对于子宫蓄脓的诊断,血常规检查显示体内有炎症变化,X光和B超确诊病犬为开放性子宫蓄脓,对病犬采取手术疗法,彻底切除卵巢和子宫。病犬术后恢复良好。     

1例犬食道阻塞的诊治及体会

犬食道异物阻塞是宠物临床医疗中常见的疾病,早期往往伴随吞咽困难,采食后很快即返流等症状,但随着病程延长病犬往往食欲废绝。临床可通过X线检查而确诊,一旦确诊要及时进行治疗。以1例犬食道异物阻塞为例,对其临床诊断、治疗及术后护理过程进行了介绍,旨在对今后临床实践提供一定的借鉴指导。