Checkpoint Inhibitors in Dogs: Are We There Yet?

Immune checkpoint inhibitors (ICI) have revolutionised cancer treatment in people. Immune checkpoints are important regulators of the body's reaction to immunological stimuli. The most studied immune checkpoint molecules are programmed death (PD-1) with its ligand (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) with its ligands CD80 (B7-1) and CD86 (B7-2).

Case report: Suspected plasmablastic lymphoma in a dog resembling the clinical presentation in humans.

Plasmablastic lymphoma (PBL) is a rare form of lymphoma in people. PBL originates from plasmablasts and usually presents with swelling/mass in the mouth/neck. A 7-year-old Mongrel dog was presented for a large oral and neck mass.

Repurposing Drugs in Small Animal Oncology.

Repurposing drugs in oncology consists of using off-label drugs that are licensed for various non-oncological medical conditions to treat cancer. Repurposing drugs has the advantage of using drugs that are already commercialized, with known mechanisms of action, proven safety profiles, and known toxicology, pharmacokinetics and pharmacodynamics, and posology. These drugs are usually cheaper than new anti-cancer drugs and thus more affordable, even in low-income countries.

Immunolabelling of Acetylated Histones 3 and 4 and Histone Deacetylases 1, 2 and 6 in Canine Soft Tissue Sarcomas.

The objective of this study was to investigate the immunolabelling of acetylated histones and histone desacetylase (HDAC) enzymes in canine soft tissue sarcomas (STSs) and to correlate them with histological and clinical features in order to identify possible prognostic and therapeutic targets in these neoplasms. Fifteen canine STS samples were evaluated and were submitted to immunohistochemistry for acetylated histones 3 (H3) and 4 (H4) and deacetylating enzymes (HDAC1, HDAC2 and HDAC6). Intense immunolabelling of H4 was seen in comparison with H3.

Inclusion of fibroblasts and collagen fibrils in the cytologic grading of canine cutaneous mast cell tumors.

Background: Fibroblasts and/or collagen fibrils have not been included in previous cytologic grading schemes of canine mast cell tumors (MCTs), and their association with biological behavior is broadly debated.

Objectives: This study aimed to evaluate the cytologic findings of canine MCT, with emphasis on the microenvironment, and propose a novel cytologic grading system correlated with mortality and histologic grade.

Material And Methods: Cytology smears of canine cutaneous MCTs were retrospectively reviewed and compared with their histopathologic counterparts using Cohen´s Kappa test.

Laboratory diagnosis of canine uroperitoneum based on cellular and biochemical characteristics of serum and abdominal fluid.

Background: Literature on the laboratory diagnosis of uroperitoneum is scarce, and it is mostly based on the biochemical findings of cavitary fluid and serum. Cell count and protein concentrations measurements are rarely used and available studies on this subject are based on a relatively small cohort of individuals.

Objectives: We aimed to use a large sample pool of dogs to establish cutoff points for biochemical analytes in cavitary fluids and serum for the diagnosis of uroperitoneum.

Epidemiological study of canine transmissible venereal tumor (CTVT) in Brazil, 2000-2020.

Canine transmissible venereal tumor (CTVT) is a contagious neoplasm, mainly transmitted through coitus. This round cell mesenchymal tumor is common in Brazil, often located in the genitalia although extragenital presentations may also occur, such as cutaneous, oral, and nasal forms. The objective of this study was to perform an epidemiological analysis of CTVT from published data in the recent academic literature to systematically demonstrate the distribution of CTVT in Brazil, identify the frequency of this neoplasm and its main diagnostic tests, and characterize its main clinical manifestations in Brazil.

LOPH: a novel chemotherapeutic protocol for feline high-grade multicentric or mediastinal lymphoma, developed in an area endemic for feline leukemia virus.

Objectives: The aim of this study was to establish the safety and efficacy of a novel multidrug lomustine-based chemotherapeutic protocol for cats with high-grade multicentric or mediastinal lymphoma, in an area endemic for feline leukemia virus (FeLV).

Methods: This prospective study included owned cats, diagnosed (cytologically) with multicentric or mediastinal lymphoma and treated with the LOPH (lomustine, vincristine [Oncovin; Antibióticos do Brasil], prednisolone and hydroxydaunorubicin [doxorubicin]) protocol. A complete blood count was performed before every chemotherapy session and any significant abnormalities recorded as possible related toxicities.

Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer.

Autonomous replication and segregation of mitochondrial DNA (mtDNA) creates the potential for evolutionary conflict driven by emergence of haplotypes under positive selection for 'selfish' traits, such as replicative advantage. However, few cases of this phenomenon arising within natural populations have been described. Here, we survey the frequency of mtDNA horizontal transfer within the canine transmissible venereal tumour (CTVT), a contagious cancer clone that occasionally acquires mtDNA from its hosts.

Assessment of Canine Mast Cell Tumor Mortality Risk Based on Clinical, Histologic, Immunohistochemical, and Molecular Features.

Mast cell tumor (MCT) is a frequent cutaneous neoplasm in dogs that is heterogeneous in clinical presentation and biological behavior, with a variable potential for recurrence and metastasis. Accurate prediction of clinical outcomes has been challenging. The study objective was to develop a system for classification of canine MCT according to the mortality risk based on individual assessment of clinical, histologic, immunohistochemical, and molecular features.

Surgical stress and postoperative complications related to regional and radical mastectomy in dogs.

Background: Surgery is the treatment of choice for regional control of mammary neoplasms in female dogs. Various surgical techniques may be used, as long as mammary gland anatomy, lymphatic drainage, and known prognostic factors are respected. The purpose of this study was to compare surgical stress-including duration of surgery, nociception and hematological changes-and postoperative complications in dogs undergoing regional and unilateral radical mastectomy.

Does haemosporidian infection affect hematological and biochemical profiles of the endangered Black-fronted piping-guan (Aburria jacutinga)?

Infectious diseases can cause deleterious effects on bird species, leading to population decline and extinction. Haemosporidia can be recognized by their negative effects on host fitness, including reproductive success and immune responses. In captivity, outbreaks of haemosporidian infection have been observed in birds in zoos and aviaries.