Pathology of Salmonella enterica Subspecies enterica Serotype Typhimurium Infection in Chinchillas (Chinchilla lanigera).

Septicaemia is the main pathological manifestation of Salmonella infection in chinchillas (Chinchilla lanigera), although information on its pathology is limited. We now describe the gross, histological and immunohistochemical features of Salmonella enterica subspecies enterica serotype Typhimurium (S. Typhimurium) infection in ranched chinchillas. Eighty-five adult pregnant chinchillas had anorexia, prostration, weight loss, hyperthermia and abortion. Necropsy of 13 animals revealed splenomegaly, hepatomegaly, mesenteric lymphadenomegaly, prominent Peyer's patches, pulmonary oedema, white pinpoint lesions in multiple organs and petechiae in the urinary bladder. In all cases, histological lesions were consistent with septicaemia, characterized by acute necrotizing hepatitis, splenitis, lymphadenitis, cystitis, pneumonia, enterocolitis, gastritis and/or nephritis. Immunohistochemistry for Salmonella spp on seven cases revealed intralesional immunolabelling in all affected organs. Salmonella sp was isolated from liver, spleen, intestinal contents and blood of 10 chinchillas. Isolates of four animals were identified as S. Typhimurium.

Causes and Lesions of Fatal Pneumonia in Domestic Cats.

Pneumonia in cats may cause severe lung injury and consequent death. We describe the post-mortem findings and aetiologies of naturally fatal pneumonia in 78 domestic cats, using gross and histopathological examinations, immunohistochemistry and microbiological techniques. Morphological patterns found were bronchopneumonia (27/78), interstitial (15/78), bronchointerstitial (13/78), granulomatous (8/78), aspiration (8/78) and pyogranulomatous (5/78) pneumonia, and pleuropneumonia (2/78). Bacterial pneumonia was identified as the most common cause (32/78), followed by viral (15/28 feline calicivirus, 10/28 felid alphaherpesvirus 1 and 3/28 both viruses), aspiration (8/78), fungal (5/78) and parasitic pneumonia (5/78). Co-infection with feline immunodeficiency virus and feline leukaemia virus was found in 54 cats. Viral infections involved cats of all ages, indicating the importance of investigating viral causes in cats with respiratory diseases, including in adult and ageing cats.

Pathological and microbiological characterization of mastitis in dairy cows.

Mastitis may be caused by a wide range of microorganisms able to induce distinct lesions in mammary tissues. This study aims to characterize the gross and microscopic features of mastitis in dairy cows and to correlate them with the pathogens involved. The udders of slaughtered dairy cows were inspected and milk samples from each mammary quarter or fragments of the parenchyma were sent for microbiological analysis, and tissue collected for histopathological evaluation. A total of 148 cows and 592 mammary quarters were collected. From these, 432 quarters (73%) had mastitis and in 160 (27%), no changes were observed. Mastitis was classified into seven patterns based on the histopathological findings, of which mixed, lymphoplasmacytic, and suppurative mastitides were the most prevalent with 35.9% (155/432), 27.1% (117/432), and 14.3% (62/432) of the cases, respectively. These patterns were associated with the same set of pathogens: Streptococcus spp., coagulase-negative Staphylococcus (CNS), Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Corynebacterium bovis. The pyogranulomatous pattern represented 7.2% (31/432) of the cases with distinct distribution based on the agent involved, mostly S. aureus and Nocardia sp. Abscedative mastitis accounted for 6.0% (26/432) of the cases; it was characterized by multiple abscesses in the parenchyma and was mainly caused by Trueperella pyogenes. Necrosuppurative mastitis represented 5.8% (25/432) of the cases which were characterized by severe parenchyma necrosis and were caused by bacteria such as CNS and Escherichia coli. The granulomatous pattern represented 3.7% (16/432) of the cases and was occasionally associated with Mycobacterium sp.

Omphalitis, urachocystitis and septicemia by Streptococcus dysgalactiae in a southern right whale calf Eubalaena australis, Brazil.

Southern right whales Eubalaena australis (SRW) use the southern coast of Brazil as a wintering and calving ground. Other than anthropogenic threats, there is limited knowledge on health and disease aspects for this species. We report the gross and microscopic findings and microbiological identification of streptococcal septicemia in a SRW calf. Main gross findings included fibrinosuppurative omphalitis and urachocystitis, suppurative cystitis, valvular endocarditis and myocarditis, embolic pneumonia, suppurative myositis and osteoarthritis, and lymphadenomegaly. Histological examination confirmed the above inflammatory processes and indicated disseminated Gram-positive coccoid septicemia. PCR analysis, based on the 16S rRNA gene from bacteria isolated on blood agar, identified Streptococcus dysgalactiae. Pathologic and microbiologic analysis indicated that ß-hemolytic S. dysgalactiae septicemia, presumably initiated as ascending omphalic infection, was responsible for stranding and death in this individual. These results further confirm pathogenicity of streptococci in cetaceans and add to the limited health and disease related pathology knowledge for this species.

Lung lesions of slaughtered horses in southern Brazil / Lesões pulmonares de equinos de matadouro-frigorífico no Sul do Brasil

Respiratory diseases cause significant veterinary costs, reduce performance and require withdrawal of horses. Yet, studies of the causes of pneumonia in horses are scant. This study aimed to describe the pathological and microbiological features of lung lesions in slaughtered horses in southern Brazil. In this study, 84 samples of lungs were examined, and a conclusive diagnosis was obtained in 74 cases. These were composed of bronchopneumonia in 50 cases, followed by granulomatous eosinophilic pneumonia (9/74), recurrent airway obstruction (7/74), lung fibrosis (4/74), lung hemorrhage (3/74) and pulmonary pythiosis (1/74). Bronchopneumonia had grossly firm focally extensive yellow to dark-red areas, which consisted microscopically of multifocal to coalescing infiltrate of degenerate neutrophils. Streptococcus equi subsp. zooepidemicus was identified in 21 of the 50 cases. Granulomatous eosinophilic pneumonia had multifocal pinpoint firm-hard yellow areas, which microscopically were composed of granulomas with a mineralized center surrounded by collagen fibers and severe infiltrate of eosinophils. Recurrent airway obstruction had mild multifocal pinpoint firm white areas that consisted microscopically of large amounts of mucus inside bronchi and bronchiole. Lung fibrosis had two patterns: focally extensive areas of consolidation and firm nodular areas. Microscopically, the first pattern had interstitial to peribronchial fibrosis, while the second had, in addition to the interstitial fibrosis, a severe pneumocyte hyperplasia and an alveolar infiltrate of neutrophils and macrophages with rare intranuclear inclusion bodies (equine herpesvirus 5, EHV-5). Pulmonary pythiosis presented a focal firm nodular area, with multiple kunkers observed in the cut surface, which corresponded microscopically to areas of necrosis surrounded by a mixed inflammatory infiltrate. At the periphery of the necrotic areas, multiple negatively stained hyphae were observed, which were evidenced through Grocott's stain and immunohistochemistry anti-Pythium insidiosum.(AU)

Doenças respiratórias causam em equinos custos significativos com tratamento veterinário, redução de performance e descarte de animais. No entanto, estudos que abordem as causas de pneumonia em equinos são escassos. O objetivo deste estudo foi descrever os aspectos patológicos e microbiológicos de lesões pulmonares em equinos abatidos em matadouro-frigorífico no Sul do Brasil. Neste estudo, 84 amostras de pulmões foram examinadas, e o diagnóstico conclusivo das condições foi obtido em 74 casos. Esses foram compostos por broncopneumonia em 50 casos, seguido por pneumonia granulomatosa eosinofílica (9/74), obstrução aérea recorrente (7/74), fibrose pulmonar (4/74), hemorragia pulmonar (3/74) e pitiose pulmonar (1/74). A broncopneumonia era caracterizada macroscopicamente por áreas focalmente extensas firmes de coloração amarelada a vermelho-escuras, as quais consistiam microscopicamente em infiltrado multifocal a coalescente de neutrófilos degenerados. Streptococcus equi subsp. zooepidemicus foi identificado em 21 dos 50 casos. A pneumonia eosinofílica granulomatosa era caracterizada por áreas multifocais puntiformes firmes a duras e amareladas, que microscopicamente eram compostas por granulomas com área central mineralizada circundados por fibras de colágeno e infiltrado acentuado de eosinófilos. A obstrução aérea recorrente era caracterizada por discretas áreas puntiformes firmes e brancacentas que consistiam microscopicamente em grande quantidade de muco no interior de brônquios e bronquíolos. A fibrose pulmonar exibia dois padrões: áreas de consolidação focalmente extensas e áreas nodulares firmes. Microscopicamente, o primeiro padrão exibia fibrose intersticial a peribronquial, enquanto no segundo padrão havia, além da fibrose intersticial, intensa hiperplasia de pneumócitos e infiltrado alveolar de neutrófilos e macrófagos com raros corpúsculos de inclusão intranucleares (herpesvírus equino 5, EHV-5). A pitiose pulmonar exibia uma área nodular firme focal com múltiplos kunkers ao corte, os quais correspondiam microscopicamente a áreas de necrose circundadas por infiltrado inflamatório misto. À periferia das áreas necróticas, múltiplas imagens negativas de hifas eram observadas, as quais foram evidenciadas através da coloração de Grocott e imuno-histoquímica anti-Pythium insidiosum.(AU)