Background: Dilated cardiomyopathy is common in dogs. This form of cardiomyopathy is the main cause of death due to heart disease in dogs. Death can occur suddenly in clinically normal animals as a result of the progression of congestive heart failure (CHF). The pathogenesis of heart failure syndrome in dogs with dilated cardiomyopathy involves activation of the neurohumoral system and immune-mediated inflammation, which leads to further progression of the condition. Heart failure syndrome in dogs with dilated cardiomyopathy is caused by the progressive loss of cardiomyocytes, apoptosis, remodeling of the left ventricle, systolic and diastolic dysfunction, arrhythmias, reduced cerebral blood flow, the involvement of other key internal organs, and intestinal dysbiosis. Aim: This study aimed to determine the immunological and inflammatory mechanisms surrounding the development of heart failure syndrome in dogs with dilated cardiomyopathy. Materials and Methods: The subjects of this study were dogs with a dilated form of cardiomyopathy (n=159), complicated by various functional classes of heart failure syndrome. Evaluation of myocardial remodeling, systolic function, and systemic hemodynamics was performed using EMP-860 Vet and PU-2200V ultrasound scanners according to the standard technique. Electrocardiography was performed with all dogs in right lateral recumbency using the EK1T-04 Midas electrocardiograph (50 mm/s speed and 1 mV gain = 1 cm). Results: In some affected animals, especially in cases of compensated dilated cardiomyopathy, leukocytosis was noted. In patients with dilated cardiomyopathy complicated by heart failure syndrome of various functional classes, the number of neutrophils was significantly increased, and the number of lymphocytes was decreased by 1.9-2.1 times when compared with those in clinically normal animals. In dogs with dilated cardiomyopathy, neutrophilic leukocytosis develops with a simple regenerative shift to the left. The results of immunological studies indicate that dogs with dilated cardiomyopathy develop T lymphocytopenia as compared with clinically normal animals. Conclusion: The central component of heart failure syndrome in dogs with dilated cardiomyopathy is the activation of the neurohumoral system and immune-mediated inflammation. The development of CHF in dogs with dilated cardiomyopathy is caused by the progressive loss of cardiomyocytes, apoptosis, remodeling of the left ventricle, systolic and diastolic dysfunction, arrhythmias, reduced cerebral blood flow, involvement of other key internal organs, and intestinal dysbiosis.

Recent studies have shown that the gut microbiota plays an important role in the pathogenesis of gastrointestinal diseases in various animal species. There are only limited data on the microbiome in cats with varying grades of dysbiosis. The purpose of the study was a detailed analysis of the quantitative and qualitative fecal microbiota spectrum in cats with intestinal dysbiosis of varying severity. The data obtained indicate that, depending on the dysbiosis severity in cats, the intestinal microbiome landscape changes significantly. It has been established that, depending on the dysbiosis severity, there is a shift in the balance between the Gram-positive and Gram-negative bacterial pools and in the nature of the isolation of specific bacteria forms, in the amount of obligate microbiota isolation, as well as individual facultative strains. When analyzing the serotyping of E. coli cultures isolated at various grades of intestinal dysbiosis severity, differences were found both in the isolation amount of various serotypes from one animal and in the prevalence of certain serotypes for each disease severity. A retrospective analysis of the fecal microbiota sensitivity in cats with dysbiosis to antibacterial drugs showed that, depending on the disease severity, the number of isolates sensitive to antibiotics increases significantly.

Background and Aim: The present study investigated the influence of liver tumor structure on life expectancy in dogs. Diseases of the liver comprise 5-25% of all non-communicable diseases in dogs, and primary hepatic tumors account for 0.6-1.3% of tumors. This research aimed to study the post-operative life span of animals with primary or metastatic tumors of the liver. Materials and Methods: During the study period, 7124 oncological operations were performed in our clinic. In total, 128 liver tumors were detected in live animals, while 323 were detected posthumously. Forty animals underwent surgery for various liver tumors. In dogs with primary liver tumors, the average age was 11.9 years and the average body weight was 15.5 kg, while in dogs with liver metastases, the mean age was 11.4 years and the average body weight was 24 kg. Results: The ratio of males to females among dogs with primary liver tumors was about 1:1 (ten females and nine males), while that among dogs with metastatic liver damage was clearly predominantly female (14 females and two males) because females often undergo surgery for cancerous mammary glands or ovaries. Conclusion: The size of tumors and the number of affected lobes had a significant effect on the post-operative life span. With a tumor size of <5 cm and a lesion covering less than two lobes of the liver, life expectancy was significantly longer and the prognosis was more favorable. In cases of large tumors or those affecting more than two lobes, life expectancy was significantly reduced and the prognosis was cautious to unfavorable.

Background and Aim: Canine testicular tumors are among the most common reproductive tract tumors in male dogs and have been studied in many countries. However, to the best of our knowledge, studies with a large sample size have not been conducted in Russia. This study aimed to provide the latest information on the prevalence of canine testicular tumors in the Veterinary Oncology Scientific Center for Small Animals "Biocontrol" in Moscow, Russia, in 2010-2020 and the characteristics of the affected canine population. Materials and Methods: A retrospective review of patients and histological reports was collected and analyzed from 358 dogs with 447 testicular tumors within 11 years. Results: The mean age of the affected dogs was 10.4 years, whereas that of dogs with Sertoli cell tumors was 9.4 years p=0.009. This study includes mixed-breed dogs (18.4%), Yorkshire Terriers (8.8%), Labrador Retrievers (7.9%), Golden Retrievers (5.0%), and Fox Terriers (3.4%). The most common tumors were interstitial cell tumors (n=227, 50.8%). In contrast, 107 (23.9%) seminomas, 80 (17.9%) Sertoli cell tumors, 19 (7.4%) mixed germ cell-sex cord-stromal tumors, and 26 (7.6%) testicular tumors developed from cryptorchid testes, which included 16 (61.5%) Sertoli cell tumors, 10 (38.5%) seminomas, and no interstitial cell tumors. Conclusion: This study provides baseline information on the prevalence of canine testicular tumors in the described population, including the median age of each tumor type and overrepresented dog breeds. We further found that the most common scrotal testicular tumor was interstitial cell tumor, whereas Sertoli cell tumor was the most common in cryptorchid testicles.

Российский университет дружбы народов ул. Микулухо-Маклая, 8/2, Москва, Россия, 117198 2 Кафедра технологии переработки и сертификации продукции животноводства Оренбургский государственный аграрный университет Челюскинцев, 18, Оренбург, Россия, 460014 Согласно полученным результатам органы иммунной системы перепелов представляют собой анатомически рассеянную, но стратегически распределенную защитную сеть: центральныерасполагаются в хорошо защищенных местах (тимус, клоакальная сумка), а периферическиена границе организма с внешней средой (железа третьего века, лимфоидные бляшки и дивертикул) и на путях циркуляции крови (селезенка). Они являются как бы «датчиками», информирующими иммунную систему организма об антигенном многообразии окружающей микрофлоры, что надо учитывать при формировании плана противоэпизоотических мероприятий при вакцинации птицы с целью создания иммунитета против инфекционных болезней.Ключевые слова: морфология, иммунология, перепела, тимус, клоакальная сумка, селезенка, железа третьего века, лимфоидный дивертикул, лимфоидные бляшки слепых кишок.Актуальность. Иммунная система объединяет органы и ткани, которые осуществляют защитные реакции организма и создают иммунитет -невосприимчивость организма к веществам, обладающим чужеродными антигенными свойствами [1]. Развившись на основе системы кроветворения, она впитала в себя все достижения эволюции многоклеточных организмов и составила наряду с метаболической, эндокринной, условно-рефлекторной четвертую форму отражения живой материи и четвертую регулирующую систему позвоночных [3]. Органы иммунной системы в соответствии со своей функцией и ролью в развитии иммунитета делятся на центральные, где происходит дифференцировка Т-и В-лимфоцитов, и периферические, где осуществляется сложный морфофункциональный комплекс по организации иммунного ответа после антигенного воздействия [2; 5].Рис. 4. Микроморфология клоакальной сумки цыпленка. Гематоксилин и эозин, об. 7, ок. 10: 1 -лимфоидные ячейки; 2 -стенка сумки;3 -просвет