Immunotherapy is a quickly developing type of treatment and the future of therapy in oncology. This paper is a review of recent findings in the field of immunotherapy with an emphasis on immune checkpoint inhibitors. The challenges that immunotherapy might face in near future, such as primary and acquired resistance and the irAEs, are described in this article, as well as the perspectives such as identification of environmental modifiers of immunity and development of anti-cancer vaccines and combined therapies. There are multiple factors that may be responsible for immunoresistance, such as genomic factors, factors related to the immune system cells or to the cancer microenvironment, factors emerging from the host cells, as well as other factors such as advanced age, biological sex, diet, many hormones, existing comorbidities, and the gut microbiome.

In summer 2023, during an outbreak of highly pathogenic avian influenza (HPAI) in cats in Poland, a 16-year-old dog was presented to the veterinary clinic with persistent, debilitating, dry cough, submandibular lymphadenomegaly, mild serous nasal discharge, and left apical heart murmur. A preliminary diagnosis of kennel cough was made and the treatment with amoxicillin/clavulanic acid and dexamethasone was initiated. Due to the lack of improvement within 2 days, a blood check-up, thoracic radiography and ultrasonography, and echocardiography were performed. Moreover, a rapid test for orthomyxovirus type A antigen in a throat swab was carried out and proved positive. The result was verified using RT-qPCR, which yielded a positive result for A/H5N1 influenza virus and negative results for A/H1N1, A/H3N2, type B influenza, and SARS-CoV-2. This case indicates that HPAI should be considered as a differential diagnosis not only in cats, but also in dogs with upper respiratory tract disease, particularly in regions experiencing A/H5N1 avian influenza outbreaks.

A European Shorthair male cat, neutered, approximately 6 years of age, was presented to the veterinary clinic due to apathy and anorexia. The cat lived mostly outdoors and was fed raw chicken meat. After 3 days of diagnostic procedures and symptomatic treatment, respiratory distress and neurological signs developed and progressed into epileptic seizures, followed by respiratory and cardiac arrest within the next 3 days. Post-mortem examination revealed necrotic lesions in the liver, lungs, and intestines. Notably, the brain displayed perivascular infiltration of lymphocytes and histiocytes. Few foci of neuronal necrosis in the brain were also confirmed. Microscopic examination of the remaining internal organs was unremarkable. The A/H5N1 virus infection was confirmed using a one-step real-time reverse transcription polymerase chain reaction (RT-qPCR). The disease caused severe neurological and respiratory signs, evidence of consolidations and the presence of numerous B lines, which were detected on lung ultrasound examination; the postmortem findings and detection of A/H5N1 viral RNA in multiple tissues indicated a generalized A/H5N1 virus infection. Moreover, a multidrug-resistant strain of Enterococcus faecium was isolated in pure culture from several internal organs. The source of infection could be exposure to infected birds or their excrements, as well as contaminated raw poultry meat but, in this case, the source of infection could not be identified.

The study involved five ferrets from one household in Poland, comprising three sick 9-week-old juveniles, their healthy mother, and another clinically normal adult, admitted to the veterinary clinic in June 2023. The juvenile ferrets displayed significant lethargy and a pronounced unwillingness to move with accompanying pulmonary distress. Prompted by concurrent outbreaks of A/H5N1 influenza virus infections in Polish cats, point-of-care tests were conducted that revealed type A influenza antigens in the throat swabs of all five ferrets. Despite treatment, one juvenile ferret exhibited dyspnea and neurological symptoms and eventually died. The two remaining ferrets recovered fully, including one severely affected showing persistent dyspnea and incoordination without fever that recovered after 11 days of treatment. In the RT-qPCR, the throat swabs collected from all surviving ferrets as well as the samples of lungs, trachea, heart, brain, pancreas, liver, and intestine of the succumbed ferret were found positive for A/H5N1 virus RNA. To our best knowledge, this is the first documented natural A/H5N1 avian influenza in domestic ferrets kept as pets. In addition, this outbreak suggests the possibility of asymptomatic A/H5N1 virus shedding by ferrets, highlighting their zoonotic potential and the advisability of excluding fresh or frozen poultry from their diet to reduce the A/H5N1 virus transmission risks.

Highly pathogenic avian influenza (HPAI) A/H5N1 has emerged as a cause of severe disease in domestic cats, but clinical data from field outbreaks remain limited. We retrospectively reviewed medical records, laboratory results, and ancillary examinations from 22 domestic cats with RT-qPCR-confirmed A/H5N1 infection diagnosed in Poland in June 2023. To the best of our knowledge, we report the first comprehensive retrospective case series from the 2023 Polish outbreak, combining 22 laboratory-confirmed cats with detailed clinical timelines and laboratory findings. For each cat, the temporal progression of clinical signs, hematology, serum biochemistry, and, when available, imaging findings were evaluated. Post-mortem examination data were not systematically available in this retrospective cohort. Notably, six of these cats were strictly indoor cats that received raw poultry meat as part of their diet. Disease onset was acute, with fever, lethargy, and anorexia rapidly progressing to severe dyspnea and neurological signs, including ataxia, seizures, and paraplegia; case fatality was 100%, with a typical interval of ≤3 days from first signs to death or euthanasia. Hematologic changes were dominated by thrombocytopenia, lymphopenia, and marked eosinopenia, consistent with a systemic inflammatory/stress leukogram. Biochemistry indicated marked tissue injury, with increased AST, LDH, and CK activities, whereas creatinine and urea remained largely within reference intervals, arguing against primary renal failure. Imaging supported the presence of interstitial to diffuse pneumonia. These data characterize the clinical and laboratory phenotypes of feline A/H5N1 infection and underscore its importance as a rapidly fatal respiratory and neurological disease with One Health implications.

Current pandemic caused by novel coronavirus SARS-CoV-2 pandemic has been described as a global health emergency. The outbreak of this virus has raised a number of questions: what exactly is SARS-CoV-2? How transmissible the novel coronavirus is? How severely affected are patients infected with SARS-CoV-2? What are the risk factors for COVID-19? What are the differences between this novel coronavirus and other coronaviruses? To answer these questions, a comparative study of three pathogenic coronaviruses that primarily invade the human respiratory system and may cause death, namely, severe acute respiratory syndrome (SARS-CoV-1), Middle East respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Middle East respiratory syndrome coronavirus (MERS-CoV). This review describes the source of origin, transmission, and pathogenicity of these viruses. Prevention of SARS-CoV-2 spreading entails home isolation of suspected cases and those with mild illnesses and strict infection control measures at hospitals that include contact and droplet precautions. The novel coronavirus spreads faster than its two predecessors – the SARS-CoV-1 and MERS-CoV – but has lower fatality rate. The global impact of this new pandemic is still uncertain, but it is a challenge to healthcare systems around the world.