Karakter patomorfoloških promena najčešćih pneumonija kod svinja na teritoriji Republike Srbije

Abstract

Swine respiratory diseases have been significantly put under control in the Republic of Serbia during the past decade, due to the implementation of appropriate prophylactic measures and diagnosis. Despite the reduced incidence of pneumonia on swine farms, respiratory diseases are still one of the most important health problem in modern pig breeding. The most common causes of bacterial pneumonia among the examined material from pig farms in Vojvodina (Serbia) are Actinobacillus pleuropneumoniae, Pasteurella multocida, Bordetella bronchiseptica and Haemophilus parasuis. These pathogens are most commonly diagnosed in feral pigs. Bacterial pneumonias are usually secondary infection manifest as exudative pneumonias that can be purulent (Pasteurella multocida, Mycoplasma hyopneumoniae), or apostematous (Bordatella bronchiseptica, Actinomyces pyogenesu) or fibrino-purulent (Haemophilus parasuis) and fibrinohemorrhagic bronchopneumonia (Actynobacillus pleuropneumoniae), mainly accompanied by fibrinous pleurisy. Purulent bronchopneumonias are characterized by the accumulation of purulent exudate in the airways and have a lobular distribution. Fibrinous bronchopneumonias are characterized by the accumulation of fibrin in the bronchoalveolar spaces, with changes affecting entire lobes. Bacteria that cause fibrinous bronchopneumonias damage blood vessels and cause changes that can be classified into stages of splenization, red hepatization, gray hepatization and resolution. Viral pneumonias are more often diagnosed in domestic swine, primarily caused by swine reproductive and respiratory virus, influenza virus, circovirus type 2, as well as Aujeszky's disease virus. Viral pneumonias in swine are acute interstitial pneumonias in which the exudative and proliferative phases can be distinguished. During the acute phase, "fetalization of the lungs" can occur, which is characterized by a reduced alveolar spaces and thickened alveolar walls. The lungs affected by interstitial pneumonia are rubbery and a rib imprint can be seen on the surface. In addition to bacterial and viral, verminous pneumonias arecommon in swine. Although the morphological characteristics of bacterial and viral pneumonias can be clearly distinguished, it is important to emphasize that the pathogenesis of swine respiratory diseases often involves several different agents and that the changes depend on the dominant etiological agent.