Auto-hemoterapia no tratamento da papilomatose canina - revisão de literatura

Abstract

Introduction: Papillomatosis is an infectious viral disease caused by Papillomavirus, belonging to the Papillomaviridae family. Highly transmissible among dogs, it is considered a benign tumor disease characterized primarily by the appearance of warts of various forms, especially in the oral cavity, lips, pharynx, and tongue. Affected animals may also exhibit dysphagia, oral bleeding, pain, malocclusion, drooling, reluctance to eat, halitosis, bacterial infections, and myiasis secondary to tumor lesions. It is a cosmopolitan disease predominantly reported in cattle, with fewer reports in dogs. It affects dogs of all ages but is more prevalent in animals under two years old. Transmission occurs through direct or indirect contact with bodily fluids or blood containing the virus. Diagnosis involves history taking, physical examination, and complementary tests such as histopathology and immunohistochemistry. Differential diagnoses include epulides, transmissible venereal tumor, and squamous cell carcinoma. Papillomatosis is generally self-limiting; however, chronic cases may necessitate antiviral and homeopathic drugs, immunomodulatory medications, autogenous vaccine application, surgical excision, cryotherapy with liquid nitrogen, electrosurgery, and systemic or intralesional chemotherapy sessions. Another treatment approach increasingly employed is autohemotherapy, an empirical method gaining popularity in veterinary medicine due to its ease of use and low cost. Typically, the prognosis is favorable if the underlying cause triggering the disease is adequately addressed. This literature review aims to explore existing scientific literature on the use of autohemotherapy in treating canine papillomatosis, providing a critical and updated analysis of research status, identifying findings, trends, and knowledge gaps in this specific area. Methodology: A systematic search for literature was conducted using academic databases such as PubMed, Scopus, Google Scholar, and academic repositories to identify studies related to the application of autohemotherapy in the treatment of canine papillomatosis. Relevant keywords including "autohemotherapy," "canine papillomatosis," "treatment," and "dogs," along with their combinations, were employed. Articles published in English, Portuguese, and other applicable languages were included. Initially, 32 articles were identified based on their titles. Subsequently, abstracts of these 32 articles were analyzed, resulting in the selection of 27 articles. Finally, after a full-text review of the selected articles, 20 studies were chosen to be included in this scientific research. Results and Discussion: Autohemotherapy is a therapeutic procedure in veterinary medicine, increasingly utilized due to its easy handling and low cost to pet owners. However, its effectiveness lacks scientific validation due to a dearth of clinical studies proving its purported benefits (Bambo, 2011). In recent years, there has been a surge in research interest in this method, also referred to in the literature as serum therapy, immunotherapy, autohemotransfusion, or autologous blood transfusion. It involves collecting autologous blood from dogs with papillomatosis and administering it without anticoagulant into their musculature to trigger a nonspecific immune response, potentially leading to papilloma regression (Bambo, 2011; Shakman, 2010; Hartmann et al., 2002; Silva et al., 2011). Autohemotherapy induces an increase in antibody levels capable of binding to cellular degradation products, neutralizing them, and consequently elevating lymphocytotoxin levels in the bloodstream (Bambo et al., 2012). The practice stimulates the activation of the mononuclear phagocytic system by increasing macrophage proportion from 5% to 22%, with this elevation sustained for five days before gradually declining to baseline levels by the seventh day, suggesting a repeated procedure interval of seven days (Moura, 2011). Venous blood collected is rich in carbon dioxide, inducing physical-chemical changes in erythrocytes upon contact with the syringe, functioning similarly to a foreign protein when administered into the organism (Queiroz, 2018). In one study, autohemotherapy treatment for oral papillomatosis in a 3-year-old, 18 kg mixed-breed dog involved collecting 1.8 ml of venous blood, administering it into the muscle, and recommending four applications with 10-day intervals. After the first application, a 60% reduction in papillomas was observed, with an 80% reduction after the second application, and complete resolution upon returning for the final application (Passos et al., 2023). Conclusion: The literature review on autohemotherapy for treating canine papillomatosis reveals an intriguing and promising field of study. Analyzed studies indicate a potential positive impact of the practice, with reports of papilloma regression associated with enhanced immune response. However, further clinical and scientific research is imperative to recognize existing study limitations, including the lack of controlled and randomized trials, result heterogeneity, and consensus on efficacy. Therefore, continued research is crucial for a deeper understanding of underlying mechanisms, optimal protocol determination, and ultimately, for providing safer and more effective guidelines for applying autohemotherapy in the context of canine papillomatosis. We acknowledge the Academic League of Animal Production and Health at UniVS for their contribution to this work.