Canine lymphoma

This article presents an overview of the literature regarding canine malignant lymphoma. It includes a discussion of etiology, classification, systemic manifestations of disease, therapy, and supportive care for patient management.     

Clonality and clinical behavior of canine indolent lymphoma

Introduction: Canine lymphomas with a follicular architecture are biologically indolent and include follicular (FL), mantle cell (MCL), marginal zone (MZL) and T‐zone (TZL) types. They are under recognized and have long survival regardless of treatment. Methods: 70 cases of canine lymphoma with fading follicular hyperplasia (FFH) received¹ over 1996 to present were reviewed. Diagnoses were determined by consensus of three pathologists^1,2 on phenotyped tissues. Clonality for B and T‐cell receptor genes was determined on DNA from paraffin blocks via PCR on 53 of 70 cases². Results: Of the total of 70 cases 52 were of B‐cell type (MZL 44, FL 4, MCL 3, MALT 1) and 9 were of T‐cell type (TZL). 9 cases of benign hyperplasia were included to assist in defining the histologic boundaries of neoplasia. Case presentation included splenic 16, and nodal 54. For 44 cases called MZL on histologic criteria, DNA was available on 33 of which 26 (78.8%) were clonal for B‐cell rearranged gene including 5 also clonal for T‐cell receptor, one clonal for T‐cell only and 6 cases negative for both and considered benign. For TZL, DNA was available on 6 of 9 cases of which 3 were clonal for T‐cell receptor, 1 for B‐cell, 1 for both and 2 polyclonal for both. Conclusions: An Ohio review of 380 cases of canine nodal lymphoma found 29% of cases to be of indolent type as described here and thus a very significant part of the patient population. Seven of 10 cases of MZL treated at Illinois with follow‐up died of other causes than lymphoma at an average of 18.8 months after diagnosis. One of the other three was lost to follow‐up, one was euthanized at owners’ choice at 9.5 m. after diagnosis still in good health and the other was terminated 3 m after diagnosis with concurrent lung carcinoma.     

Canine nodular dermatophytosis (kerion): 23 cases

Dermatophytosis is a common zoonotic disease, and one of its clinical presentations in the dog is nodular dermatophytosis (kerion). Because the infection is located within the dermis, routine diagnostic tests such as a Wood's lamp examination, microscopic examination of hair shafts for fungal elements and fungal culture can yield negative results. In such cases, histopathological examination with routine and special stains (periodic acid-Schiff, Gomori methenamine silver) is required to confirm the diagnosis. Nodular dermatophytosis in 23 dogs of different breed, age and sex with single or multiple nodules is described. Twelve dogs had a single nodule, and 11 dogs showed multiple lesions. Wood's lamp examination was negative in all cases. Microscopic examination of plucked hairs showed arthrospores in 8 of 23 cases. Skin scrapings in mineral oil looking for arthrospores and/or hyphae were positive in 12 cases. Impression smears of exudates were diagnostic in 21 of 23 cases (91%), showing arthrospores within fragments of hair shafts or free among neutrophils and macrophages (pyogranulomatous inflammation). Histopathology was performed in two cases. Fungal culture was positive for Microsporum canis in 16 dogs and for Microsporum gypseum in one dog. In six cases, the causative agent was not identified by fungal culture. All dogs were treated with systemic antifungal therapy and in eight cases with concurrent antibiotic therapy. Nodular dermatophytosis resolved in all dogs with the prescribed treatments within 4 to 8 weeks. Transmission to people or other pets in the home was not found.     

Canine episcleritis, nodular episclerokeratitis, scleritis, and necrotic scleritis.

This article provides a brief review of human episcleritis and scleritis, because the pathogenesis, diagnosis, and treatment of these disorders are perhaps the best understood of all species of animals. The clinical and light microscopic manifestations, therapeutic options, and prognosis for primary and secondary episcleritis and scleritis in dog are also reviewed. The focus of this article is on primary and secondary inflammatory conditions that originate in the episclera and sclera caused by idiopathic or known etiologies.     

Canine multicentric lymphoma 2: Comparison of response to two chemothera-peutic protocols

This paper describes the chemotherapeutic response of 90 cases of canine multicentric lymphoma. All the dogs were treated with a combination protocol using cyclophosphamide, vincristine and prednisolone. Forty-seven dogs received additional intravenous cytosine arabinoside on the first four days of treatment. Eighty-eight per cent of all cases had shown either a complete or partial response to this treatment at six weeks from the start of treatment and the overall mean survival time was 37 weeks (SD = 35.8). There was no significant difference in response or survival rates between the two treatment groups. The age and sex of the patient, the clinical stage of the disease and previous treatment with corticosteroids were all analysed to determine whether these parameters were of prognostic significance. Those dogs in clinical stages 4 and 5 carried a worse prognosis than those in stages 1 to 3. Previous treatment with corticosteroids adversely affected both tumour response and patient survival rates.     

Canine inflamed nonepitheliotropic cutaneous T‐cell lymphoma: a diagnostic conundrum

Background –  Cutaneous T‐cell lymphoma (CTCL) in dogs is a heterogeneous disease complex, which consists of nonepitheliotropic (NE) and epitheliotropic forms. These lymphomas are readily recognized by the presence of dominant populations of cytologically atypical lymphocytes. Objective –  The objective of this study was to introduce the key features of inflamed NE‐CTCL, which is easily confused with reactive, inflammatory histiocytic disease. Animals –  Twenty‐four dogs (mean age 7.5 years) presented with inflamed NE‐CTCL. Lesions presented as nodules, plaques or masses. An initial diagnosis of cutaneous reactive histiocytosis (11 dogs) or histiocytic neoplasia (three dogs) was made by primary pathologists. Methods –  Lesions were assessed by histology and immunohistochemistry to detect canine leukocyte antigens. Lesional genomic DNA was extracted and gene rearrangement analysis of the T‐cell receptor γ locus was assessed. Results –  The cutaneous lesions consisted of pleocellular infiltration of the dermis with variable extension into the subcutis. The lesions often surrounded vessels and adnexae. Epitheliotropism was minimal or lacking. Small lymphocytes, plasma cells and intermediate to large, cytologically atypical lymphocytes were scattered between prominent histiocytic infiltrates. Atypical lymphocytes often had marked variation in the intensity of CD3 expression. Molecular clonality analysis of the T‐cell receptor γ locus revealed clonal expansion of T cells in 22 of 23 dogs tested. Conclusion –  The recognition of inflamed NE‐CTCL and its differentiation from cutaneous reactive histiocytosis depends on careful assessment of lymphocyte morphology and immunostaining patterns. Confirmation of the diagnosis is best accomplished by T‐cell antigen receptor gene rearrangement analysis.     

Canine cutaneous epitheliotropic T-cell lymphoma with vesiculobullous lesions resembling human bullous mycosis fungoides

The broad spectrum of clinical signs in canine cutaneous epitheliotropic T-cell lymphoma mimics many inflammatory skin diseases and is a diagnostic challenge. A 13-year-old-male castrated golden retriever crossbred dog presented with multifocal flaccid bullae evolving into deep erosions. A shearing force applied to the skin at the periphery of the erosions caused the epidermis to further slide off the dermis suggesting intraepidermal or subepidermal separation. Systemic signs consisted of profound weight loss and marked respiratory distress. Histologically, the superficial and deep dermis were infiltrated by large, CD3-positive neoplastic lymphocytes and mild epitheliotropism involved the deep epidermis, hair follicle walls and epitrichial sweat glands. There was partial loss of the stratum basale. Bullous lesions consisted of large dermoepidermal and intraepidermal clefts that contained loose accumulations of neutrophils mixed with fewer neoplastic cells in proteinaceous fluid. The lifted epidermis was often devitalized and bordered by hydropic degeneration and partial epidermal collapse. Similar neoplastic lymphocytes formed small masses in the lungs associated with broncho-invasion. Clonal rearrangement analysis of antigen receptor genes in samples from skin and lung lesions using primers specific for canine T-cell receptor gamma (TCRγ) produced a single-sized amplicon of identical sequence, indicating that both lesions resulted from the expansion of the same neoplastic T-cell population. Macroscopic vesiculobullous lesions with devitalization of the lesional epidermis should be included in the broad spectrum of clinical signs presented by canine cutaneous epitheliotropic T-cell lymphoma.     

Canine cutaneous epitheliotropic T‐cell lymphoma: a review of 30 cases

This retrospective study reviewed the clinical, histological and immunohistochemical features of 30 European cases of canine cutaneous epitheliotropic T‐cell lymphoma (CETL). The clinical presentation was highly variable and was not associated with the disease subtype. Diffuse erythema (86.6%) with scaling (60%) and focal hypopigmentation (50%) were the most common lesions. The skin was uniformly involved but muco‐cutaneous junctions or mucosae were affected in 50% of cases. The median age at diagnosis was 10 years (SD 2.79, range 4–15) and the median time between onset and final diagnosis was 5 months (SD 3.79, range 0–12). Five cases occurred in Bichon Frises. There was no evidence of a previous history of chronic dermatitis in any cases. Histologically, the follicular epithelium was affected in 86.7% of cases. One case with mainly follicular disease was considered folliculotropic mycosis fungoides (MF), but no follicular mucinosis was observed. Epidermal Pautrier’s microabscesses were uncommon (23.3%). Sweat glands were infiltrated in 70% of cases. Immunohistochemistry confirmed T‐cell neoplasia in all cases. B cells infiltrated as individual cells or formed linear bands or ectopic follicles at the base of the neoplasm. Ki67 labelling revealed a range of proliferation indices but did not correlate with severity. A final diagnosis of classical MF was made in 40% of the dogs, MF d’emblé in 36.7%, generalized Pagetoid reticulosis in 20% and localized Pagetoid reticulosis in one case (Woringer–Kolopp Pagetoid reticulosis). The median survival time after diagnosis was 6 months and this did not change appreciably with therapy (lomustine or prednisolone).     

Canine lymphoid leukaemia and lymphoma with bone marrow involvement: A review of 24 cases

Eleven cases of canine lymphoid leukaemia (10 acute and one chronic) were compared with 13 cases of canine lymphoma with bone marrow abnormalities, with regard to presentation, treatment and survival. Breed, age, and sex were similar for the two groups of dogs, but there was a marked difference in presenting signs, haematological parameters and bone marrow analysis, with the leukaemic dogs showing more severe changes. The clinicopathological features of these cases are reported in this paper and discussed with regard to prognosis. The mean survival time was significantly lower (43 days) in dogs treated for acute lymphoblastic leukaemia than for dogs treated for lymphoma with bone marrow abnormalities (351 days).     

犬的繁殖

犬是单次发情的,小型品种犬到达性成熟要比大型品种早些,公犬的性成熟比母犬延迟几周,野犬只在冬季交配,而家犬四季都能繁殖,但发情的频率趋向于春末和冬初。     

犬黄曲霉毒素中毒

黄曲霉毒素是由黄曲霉和寄生曲霉产生的有毒代谢产物。当犬采食被黄曲霉和寄生曲霉污染的食物,常可发生中毒。     

常见的犬的人畜共患病

世界上人畜共患病种类很多,常听说的“大名鼎鼎”的如:口蹄疫、狂犬病、鼠疫、猪链球菌病、禽流感、非典(SARS)、疯牛病等。近年来,由犬猫引起的人畜共患病也呈上升趋势,犬猫的人畜共患病也要引起人们的警惕,它直接关系到人们的身体健康。     

Canine mycoplasmas

This review aims to summarise our current understanding of the role of mycoplasmas in domestic dogs. Canine mycoplasmology is a small field, with less than 50 publications in the past 40 years. In this time we have gained knowledge about the number of species and have made associations with infections in dogs. However much evidence is still lacking. The importance of all canine mycoplasmas remains unknown, yet certain species are associated with canine anaemia (Mycoplasma haemocanis), respiratory disease (Mycoplasma cynos) and urogenital tract infections (Mycoplasma canis). Mycoplasmas can be isolated in pure culture from canine clinical specimens and it is hoped that this review will stimulate veterinarians to consider mycoplasmas as a potential cause of disease in dogs, especially when antibiotic therapy is failing.     

犬的繁殖

<正>犬是单次发情的,在两次发情周期之间的数月出现静止。小型品种犬到达性成熟要比大型品种早些。公犬的性成熟比母犬延迟几周,这可通过渴望交配和精液里出现大量的精子来评定和判断。