Vinblastine/prednisolone chemotherapy leads to hematological toxicity in dogs with high-grade or metastatic mast cell tumors.

Objective: To determine the myelosuppressive effects/hematological toxicities, other general toxicities, and when these occur during vinblastine/prednisolone chemotherapy in dogs bearing high-grade or metastatic cutaneous/subcutaneous mast cell tumors (MCTs).

Methods: Medical records were retrospectively reviewed between November 1, 2016, and March 1, 2023. Thirty client-owned dogs with histopathologically confirmed cutaneous high-grade MCTs/metastatic subcutaneous MCTs and that subsequently completed a 12-week vinblastine/prednisolone chemotherapy protocol were included.

Impact of palliative-intent radiotherapy with or without chemotherapy on lameness in flat coat retrievers with localised periarticular histiocytic sarcoma - a retrospective cohort, single institution study.

Histiocytic sarcoma (HS) is a common tumour in flat coat retrievers (FCRs) often affecting periarticular tissues and joints. Palliative-intent radiotherapy, seeks to achieve local tumour control, pain relief and improve limb function. However, the effect of palliative-intent radiotherapy on analgesic levels of dogs with localised HS has not been studied.

Sarcoma Predisposition in Dogs with a Comparative View to Human Orthologous Disease.

Sarcomas are malignant tumors arising from the embryonic mesodermal cell lineage. This group of cancers covers a heterogenous set of solid tumors arising from soft tissues or bone. Many features such as histology, biological behavior and molecular characteristics are shared between sarcomas in humans and dogs, suggesting that human sarcoma research can be informative for canine disease, and that dogs with sarcomas can serve as relevant translational cancer models, to aid in the understanding of human disease and cancer biology.

Effect of pituitary-dependent hypercortisolism on the survival of dogs treated with radiotherapy for pituitary macroadenomas.

Background: Radiotherapy (RT) is an effective treatment for dogs presented with neurologic signs caused by pituitary tumors. However, its impact on the outcome of concurrent pituitary-dependent hypercortisolism (PDH) is controversial.

Objectives: Determine whether dogs with PDH have longer survival after pituitary RT compared with dogs with nonhormonally active pituitary masses and to evaluate whether clinical, imaging, and RT variables affect survival.

Serum amyloid A and other clinicopathological variables in cats with intermediate- and large-cell lymphoma.

Objectives: Serum amyloid A (SAA) concentrations are increased in cats with lymphoma vs healthy cats; however, the association between SAA concentrations and prognosis in cats with lymphoma is unclear. The aim of this study was to evaluate if SAA concentrations were different in cats with nasal vs non-nasal lymphoma, if SAA concentrations are prognostic in patients treated with high-dose chemotherapy and if SAA concentrations are correlated with other clinicopathological variables.

Methods: Cats diagnosed with intermediate- or large-cell lymphoma between 2012 and 2022 with SAA concentration data available were included.

Comparison of the Clinical Characteristics of Histiocytic Sarcoma in Bernese Mountain Dogs and Flat-Coated Retrievers.

Histiocytic sarcoma (HS) is an aggressive malignant tumor of histiocytes, which can affect almost any organ in the body and is characterized by a broad array of tumor locations and clinical presentations. So far, no complete overview exists of the array of clinical aspects of HS in specific dog breeds in large groups. Therefore, we investigated the clinical characteristics of HS in a population of Bernese Mountain Dogs (BMD; n = 365) and Flat-Coated Retrievers (FCR; n = 289), which are two of the most affected dog breeds.

Outcomes of adjunctive radiation therapy for the treatment of mast cell tumors in dogs and assessment of toxicity: A multicenter observational study of 300 dogs.

Background: Radiation therapy is commonly used as an adjunct to incomplete surgical excision in dogs with mast cell tumors (MCT), but the optimal dose and fractionation regimen have yet to be determined.

Hypothesis: We assessed outcomes (time to local recurrence, patient survival and toxicity) of a large population of dogs with MCT that received adjunctive radiation therapy.

Animals: Three hundred dogs with 302 MCT treated using adjunctive radiation therapy.

Effect of radiotherapy on freedom from seizures in dogs with brain tumors.

Background: Seizures are a common presenting sign in dogs with brain tumors.

Hypothesis/objectives: To investigate the effect of radiotherapy on freedom from brain tumor-associated seizures and survival time in dogs.

Animals: Thirty-two client-owned dogs with brain tumor-associated seizures; 18 received medical treatment and radiotherapy, 14 received medical treatment alone.

Cross-species genomic landscape comparison of human mucosal melanoma with canine oral and equine melanoma.

Mucosal melanoma is a rare and poorly characterized subtype of human melanoma. Here we perform a cross-species analysis by sequencing tumor-germline pairs from 46 primary human muscosal, 65 primary canine oral and 28 primary equine melanoma cases from mucosal sites. Analysis of these data reveals recurrently mutated driver genes shared between species such as NRAS, FAT4, PTPRJ, TP53 and PTEN, and pathogenic germline alleles of BRCA1, BRCA2 and TP53.

Outcomes following surgical excision or surgical excision combined with adjunctive, hypofractionated radiotherapy in dogs with oral squamous cell carcinoma or fibrosarcoma.

OBJECTIVE To compare outcomes of dogs treated surgically for oral, nontonsillar, squamous cell carcinomas (SCCs) and fibrosarcomas (FSAs) with outcomes of dogs treated with a combination of surgery and postoperative radiotherapy; to explore whether postoperative, hypofractionated radiotherapy improved outcomes of dogs with incomplete excisions; and to identify prognostic factors associated with outcome. DESIGN Retrospective cohort study. ANIMALS 87 client-owned dogs that had undergone maxillectomy or mandibulectomy for treatment of oral SCC or FSA between 2000 and 2009.

Clinical, histological, immunohistochemical and genetic factors associated with measurable response of high-risk canine mast cell tumours to tyrosine kinase inhibitors.

The aim of the present prospective-retrospective study was to evaluate the response of high-risk canine mast cell tumours (MCTs) to tyrosine kinase inhibitors (TKIs) and to correlate this with prognostic factors. A total of 24 dogs presented with macroscopic cutaneous MCTs at disease stage II or III, and therefore, at high-risk of associated mortality, were included in the study and treated with masitinib (n=20) or toceranib (n=4). A total of 12/24 dogs achieved an objective response and the overall survival (OS) for all subjects was 113 days.

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers.

Background/aim: Histiocytic sarcoma (HS) represents a group of malignant canine tumors to which Bernese Mountain Dogs (BMD) and Flatcoated Retrievers (FCR) are predisposed. The differential diagnosis for HS is broad, encompassing round cell tumors, sarcomas and other histiocytic diseases. The aim of this study was to establish morphological and immunohistochemical criteria for routine use on formalin-fixed, paraffin-embedded samples and cytological smears for the recognition and differentiation of canine HS and its subtypes.

Feline mediastinal lymphoma: a retrospective study of signalment, retroviral status, response to chemotherapy and prognostic indicators.

Historically, feline mediastinal lymphoma has been associated with young age, positive feline leukaemia virus (FeLV) status, Siamese breed and short survival times. Recent studies following widespread FeLV vaccination in the UK are lacking. The aim of this retrospective multi-institutional study was to re-evaluate the signalment, retroviral status, response to chemotherapy, survival and prognostic indicators in feline mediastinal lymphoma cases in the post-vaccination era.

Breed-predispositions to cancer in pedigree dogs.

Cancer is a common problem in dogs and although all breeds of dog and crossbred dogs may be affected, it is notable that some breeds of pedigree dogs appear to be at increased risk of certain types of cancer suggesting underlying genetic predisposition to cancer susceptibility. Although the aetiology of most cancers is likely to be multifactorial, the limited genetic diversity seen in purebred dogs facilitates genetic linkage or association studies on relatively small populations as compared to humans, and by using newly developed resources, genome-wide association studies in dog breeds are proving to be a powerful tool for unravelling complex disorders. This paper will review the literature on canine breed susceptibility to histiocytic sarcoma, osteosarcoma, haemangiosarcoma, mast cell tumours, lymphoma, melanoma, and mammary tumours including the recent advances in knowledge through molecular genetic, cytogenetic, and genome wide association studies.

Evaluation of variants of melanoma-associated antigen genes and mRNA transcripts in melanomas of dogs.

OBJECTIVE-To characterize variability in melanoma-associated antigen (MAA) genes and gene expression in melanomas of dogs. ANIMALS-18 dogs with malignant melanomas and 8 healthy control dogs. PROCEDURES-cDNA was prepared from malignant melanoma biopsy specimens and from pigmented oral mucocutaneous tissues of healthy control dogs.

Disruption of chromosome 11 in canine fibrosarcomas highlights an unusual variability of CDKN2B in dogs.

Background: In dogs in the western world neoplasia constitutes the most frequently diagnosed cause of death. Although there appear to be similarities between canine and human cancers, rather little is known about the cytogenetic and molecular alterations in canine tumours. Different dog breeds are susceptible to different types of cancer, but the genetic basis of the great majority of these predispositions has yet to be discovered.

Development of a multiple-marker polymerase chain reaction assay for detection of metastatic melanoma in lymph node aspirates of dogs.

Objective: To develop a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect canine melanoma-associated antigens (MAAs) and to use this technique to screen aspirates of lymph nodes (LNs) for evidence of metastatic spread of oral malignant melanoma.

Animals: 7 dogs with oral malignant melanoma and 4 dogs with multicentric lymphosarcoma.

Procedures: We prepared cDNA from melanoma tumor biopsies and fine-needle aspirates obtained from submandibular LNs of dogs with oral malignant melanoma or multicentric lymphosarcoma.