Studies of the histopathological changes and presence of amyloid b protein (Ab) deposits in the aged feline brain

A wide variety of age-related changes has been described in the brain of many species. The aim of this study was to detect the histological lesions as well as the peptides of Αβ-forming amyloid deposits in the aged feline brain. Additionally, an effort was made to assess the usefulness of the cat as a natural animal model of normal aging and neurodegenerative diseases in humans. 20 aged cats (7,5-21 years old) and 3 control cats (0,6-3 years old) were used in this study. The cats were either admitted dead for necropsy or euthanised due to debilitating non-neurological disorders. The brains were routinely fixed and samples were collected from the frontal, parietal and temporal lobes, the hippocampus, the corpus striatum, the thalamus, and the cerebellum, for histological and immunohistochemical examination. Subsequently, serial paraffin sections from all samples were stained with hematoxylin and eosin (HE), periodic acid Schiff (PAS), Kluver-Barrera’s luxol fast blue, modified alkaline Congo red and modified Bielschowsky. Single-labelling immunostaining by avidin-biotin peroxidase complex (ABC) method was also performed on adjacent sections, to detect ΑβPP and other Αβ peptides as well as to examine the reaction of astrocytes. Histologically, diffuse fibrosis of the choroid plexus and the meninges was seen. Vascular fibrosis and/or hyalinosis were detected in the same tissues as well as in the brain parenchyma. Μeningeal and choroid plexus vessels were often calcified. The perivascular presence of PAS- positive foamy cells was an invariable feature. Satelitosis, neuronophagia and PAS positive granular lipofuskin deposits within the cytoplasm of neurons and microglial cells were also constant findings. Neuronal degeneration and necrosis were found in all samples examined. The intensity of degenerative and necrotic lesions correlated positively with the age of the cats. White and grey matter vacuolation, neuraxonal degeneration, reactive gliosis, and presence of lafora bodies and spheroids, were additional findings in all aged animals. In a few brains, spherical to ovoid structures stained exclusively with H-E were occasionally noticed. The immunohistochemical study revealed age-dependent isomorphic gliosis and accumulation of AβPP exclusively into the cytoplasm of both neuronal and choroid plexus epithelial cells. Moreover, Aβ42 and Aβ40 peptides and less commonly Aβ (8-17) and Panβ (15-30) were evident in the neuronal cytoplasm, the wall of meningeal and parenchymal vessels as well as in the neuropil and the extracellular space of the white matter. The SP consisted of non-fibrillar Aβ and were classified into two distinct types: diffuse and stellate. The diffuse SP were divided into two subtypes: condensed and cloud-like, both comprising mainly of Aβ42 and Αβ40 peptides. In contrast, the stellate SP were formed exclusively by Aβ42. Finally, it is noteworthy that the Aβ40 and Αβ42 peptides were also detected in the cytoplasm of choroid plexus epithelial cells. The histopathological findings and the depositions of Αβ were gradually increased with age. The spectrum of lesions characterizing the aged cats was not observed in the brains of the control animals. A comparative study of brain lesions among aged animals of different breeds concluded that Σιάμ cats appear to be more susceptible to age-related lesions than DSH and DLH. In conclusion, the histopathological findings, the localization and nature of total Aβ and of Aβ peptides and the reaction of astrocytes in the brain of aged cats is similar in many ways with those of humans with AD or non-demented aged humans. Thus, we suggest that the cat may be a suitable animal model of human neurodegenerative and age-related diseases.Αλλοιώσεις του εγκεφάλου που συνδέονται με την πάροδο της ηλικίας, έχουν αναφερθεί σε διάφορα είδη ζώων και τον άνθρωπο. Στην παρούσα έρευνα μελετήθηκαν οι ιστοπαθολογικές αλλοιώσεις, καθώς και η παρουσία των διάφορων πεπτιδίων της πρωτεΐνης Αβ, τα οποία συγκροτούν τις εναποθέσεις β αμυλοειδούς, στον εγκέφαλο των παρήλικων γατών. Επίσης, εκτιμήθηκε η δυνατότητα χρησιμοποίησης της γάτας ως ζώο-πρότυπο για τη μελέτη της γήρανσης και των διάφορων νευροεκφυλιστικών νοσημάτων του ανθρώπου. Για την έρευνα αυτή χρησιμοποιήθηκαν συνολικά 23 γάτες από τις οποίες οι 20 ήταν παρήλικες (7,5-21 ετών) και οι 3 νεαρής ηλικίας (0,6-3 ετών). Οι τελευταίες χρησιμοποιήθηκαν ως μάρτυρες. Τα ανωτέρω ζώα δεν εμφάνιζαν κλινικά συμπτώματα, που να προέρχονται από το ΚΝΣ και ιδιαίτερα από τον εγκέφαλο. Μετά το θάνατο ή την ευθανασία των ζώων λαμβάνονταν αμέσως ιστοτεμάχια από το μετωπιαίο, το βρεγματικό και τον κροταφικό λοβό, τον ιππόκαμπο, την παρεγκεφαλίδα, το θάλαμο και το ραβδωτό σώμα για ιστοπαθολογική και ανοσοϊστοχημική εξέταση. Ειδικότερα, για την ιστοπαθολογική εξέταση όλων των παραπάνω περιοχών χρησιμοποιήθηκαν διαδοχικές τομές παραφίνης και εφαρμόστηκαν συνολικά 5 ιστολογικές μέθοδοι (Η-Ε, PAS, Kluver-Barrera, τροποποιημένες χρώσεις του ερυθρού του Κογκό και Bielschowsky). Παράλληλα, για την ανοσοϊστοχημική εξέταση εφαρμόστηκε η μέθοδος ABC με στόχο την ανίχνευση, τόσο της ΑβPP και των διάφορων πεπτιδίων της Αβ, όσο και του βαθμού ενεργοποίησης των αστροκυττάρων. Οι ιστοπαθολογικές αλλοιώσεις χαρακτηρίζονταν από την παρουσία ίνωσης, που αφορούσε το χοριοειδές πλέγμα και τις μήνιγγες, καθώς και ίνωσης ή/και υαλίνωσης, που διαπιστώθηκαν στα αγγεία των ίδιων περιοχών και του εγκεφάλου. Επιπλέον, σχετικά συχνό εύρημα αποτελούσε η ασβεστοποίηση των αγγείων των μηνίγγων και του χοριοειδούς πλέγματος. Επιπρόσθετα, χαρακτηριστική ήταν η διαπίστωση στον εγκέφαλο αρκετών ζώων, της παρουσίας μικρονευρογλοιακών κυττάρων, που εντοπίζονταν συνήθως περιαγγειακά και έφεραν κενοτόπια στο κυτταρόπλασμά τους. Η δορυφόρωση, οι νευρωνοφαγίες και η συγκέντρωση κοκκίων λιποφουσκίνης στο κυτταρόπλασμα των νευρώνων και των μικρονευρογλοιακών κυττάρων αποτελούσαν σταθερά ευρήματα για όλα τα παρήλικα ζώα που εξετάστηκαν. Η εκφύλιση και η νέκρωση των νευρώνων διαπιστώθηκαν σε όλες τις περιοχές του εγκεφάλου των παρήλικων γατών, με την έντασή τους να αυξάνεται με την πάροδο της ηλικίας. Τέλος, σωμάτια Lafora, σφαιροειδή, κενοτόπια στη φαιά και τη λευκή ουσία του εγκεφάλου, εκφύλιση των νευρικών ινών και ενεργοποίηση των αστροκυττάρων διαπιστώθηκαν στην πλειονότητα των εγκεφάλων που εξετάστηκαν, ενώ λίγα ήταν τα περιστατικά στα οποία παρατηρήθηκαν σωμάτια που ανιχνεύονταν μόνο με τη χρώση Η-Ε

Bronchoscopy and Lung Fine-Needle Aspiration for Antemortem Evaluation of Pulmonary Involvement in Dogs with Naturally Occurring Canine Leishmaniosis

Clinical manifestations from the lower respiratory tract are rare in canine leishmaniosis (CanL), making bronchoscopy and lung fine-needle aspiration (FNA) seldomly justified. The aim of this prospective study was to investigate the involvement of Leishmania infantum in the lungs of dogs with naturally occurring CanL by bronchoscopy and examination of bronchoalveolar lavage fluid (BALF), bronchial mucosa biopsies, and FNA, using immunodiagnostics. Dogs with relevant concurrent diseases and azotemia were excluded. Cough was detected in 5/31 (16.1%) dogs. Lesions (hyperemia, edema, mucosal granularity, secretions) were identified upon bronchoscopy in 19/31 (61.3%) dogs. The cytology of BALF revealed histiocytic inflammation in 14/31 (45.2%) dogs; the parasite was identified in one dog (3.2%). The immunofluorescence antibody test in BALF was positive in 15/31 (48.4%) dogs. Histopathology of bronchial mucosa and/or adjacent alveoli revealed lesions (mononuclear cell infiltration, fibrosis, edema, thickening of the inter-alveolar septa) in 24/31 (77.4%) dogs, with no Leishmania amastigotes. Positive antigen staining was observed within the cytoplasm of mononuclear cells in immunocytochemistry and immunohistochemistry. Μononuclear cells showed antigenic positivity in bronchial mucosa (27/31; 87.1%), BALF (30/31; 96.8%), and lung FNA (27/31; 87.1%). In conclusion, lungs seem to be affected from CanL more commonly than previously believed, and bronchoscopy allows obtaining valuable samples for antemortem diagnosis

A randomized controlled study on the efficacy of a novel combination vaccine against enzootic pneumonia (Mycoplasma hyopneumoniae) and porcine Circovirus type 2 (PCV2) in the presence of strong maternally derived PCV2 immunity in pigs

Abstract Background Mycoplasma hyopneumoniae (M. hyo) and Porcine Circovirus Type 2 (PCV2) are major pathogens that cause significant health problems in swine worldwide. Maternal derived immunity (MDI) has been suggested as a significant immediate defence factor for newborn piglets and may interfere with piglet’s vaccination-induced immunity. The study aimed to assess the efficacy of a novel combination vaccine (consisting of PCV2 subunits and inactivated M. hyo strain J), against PCV2 and M. hyo natural infection [Porcilis® PCV M Hyo (MSD Animal Health, Boxmeer, the Netherlands)], in the presence of strong maternally derived PCV2 immunity (antibody titre averaged 11.08 log2), under field conditions. The study was performed according to a controlled, randomized and blinded design in a Greek swine unit with Enzootic Pneumonia (EP) and subclinical PCV2 infection. In total, 600 healthy three-week-old suckling piglets were allocated randomly, either to treatment (vaccinated with the test product) or control group (injected with sterile buffered saline). Results Vaccination significantly reduced the severity of lung lesions at slaughter (lesions of cranio-ventral pulmonary consolidation) (P < 0.001). The overall mean lung lesion score (LLS) was 9.6 in the vaccinated group and 12.2 in controls. The level of PCV2 viraemia was significantly reduced in vaccinated pigs. Furthermore, 25 g higher average daily weight gain (ADWG) was observed during the finishing phase (P < 0.001) and 18 g greater ADWG overall (P < 0.001). Conclusions Results of LLS, PCV2 viremia and ADWG support the test product’s efficacy in the face of strong maternally derived PCV2 immunity

Bilateral Renal Large B Cell Lymphoma in a Dog: A Case Report and Review of the Literature

Canine lymphoma is a commonly reported neoplasia and, in most dogs, arises from lymph nodes before spreading to other organs. Renal lymphoma rarely occurs, and kidneys usually are a secondary site of origin. Primary renal lymphoma is infrequently described in the veterinary literature. In this study, we present a rare case of primary renal lymphoma in a dog and a review of similar cases. A 3-year-old male dog was admitted due to anorexia, weakness and vomiting. Clinical examination revealed bilaterally enlarged kidneys. Imaging demonstrated the presence of multiple renal masses. Cytology of abdominal fluid and kidneys led to the diagnosis of large cell lymphoma. Histopathology and immunohistochemistry on tissue samples taken from the kidneys confirmed the cytological diagnosis of lymphoma and categorized it as primary bilateral renal large B-cell lymphoma (LBCL)

Avian Mycobacteriosis and Molecular Identification of <em>Mycobacterium avium</em> Subsp. <em>avium</em> in Racing Pigeons (<em>Columba livia domestica</em>) in Greece

In this report, cases of avian mycobacteriosis in two lofts of racing pigeons are described. Three racing pigeons of 2-year old from the first loft (A) and four racing pigeons of 4–5 years old from the second loft (B) were submitted to the Unit of Avian Medicine for clinical examination and necropsy. In the case history chronic and debilitating disease was reported. The clinical signs included emaciation, depression, lameness, periorbital swelling and diarrhea, although the appetite was normal. Post mortem lesions involved an enlarged spleen with multiple different sized yellow nodules. Similar lesions were also observed in the liver, conjunctiva of the inferior eyelids and in the femoral bone marrow. The suspicion of avian mycobacteriosis was based on history, clinical signs and typical lesions. In order to confirm the diagnosis, histopathology was performed on tissue sections and revealed the presence of multiple granulomas with central necrosis. In addition, Ziehl-Neelsen positive bacilli were observed in histological sections and smears from the granulomas of the affected tissues. Molecular analysis identified the causative agent as Mycobacterium avium subsp. avium. This is the first case report of avian mycobacteriosis in Greece, which describes the presence of granulomatous conjunctivitis and the molecular identification of M. avium subsp. avium as the causative agent in racing pigeons

Bilateral Renal Large B Cell Lymphoma in a Dog: A Case Report and Review of the Literature

Canine lymphoma is a commonly reported neoplasia and, in most dogs, arises from lymph nodes before spreading to other organs. Renal lymphoma rarely occurs, and kidneys usually are a secondary site of origin. Primary renal lymphoma is infrequently described in the veterinary literature. In this study, we present a rare case of primary renal lymphoma in a dog and a review of similar cases. A 3-year-old male dog was admitted due to anorexia, weakness and vomiting. Clinical examination revealed bilaterally enlarged kidneys. Imaging demonstrated the presence of multiple renal masses. Cytology of abdominal fluid and kidneys led to the diagnosis of large cell lymphoma. Histopathology and immunohistochemistry on tissue samples taken from the kidneys confirmed the cytological diagnosis of lymphoma and categorized it as primary bilateral renal large B-cell lymphoma (LBCL)

First Detection and Identification of FAdV-8b as the Causative Agent of an Outbreak of Inclusion Body Hepatitis in a Commercial Broiler Farm in Greece

Inclusion body hepatitis (IBH) is an economically important disease of chickens, with a worldwide distribution, caused by Fowl Aviadenoviruses (FAdVs). Currently, the increased number of cases, the virulence of the isolate strains, as well as the lack of cross-species protection highlight that detailed in-field data are fundamental for the development of successful control strategies. This case report provides a detailed clinicopathological investigation of an unusual IBH outbreak in a commercial broiler farm in the region of Macedonia, Greece. The farm consisted of 64,000 birds, originated from the same breeder stock and placed in three different houses (Flock A&ndash;C). At 20 days of age, a sudden increase in daily mortality was recorded in Flock A. It is worth mentioning that, although all flocks were serologically (indirect ELISA) and molecularly (RT-PCR) positive for FAdV, the mortality rate, attributed to IBH, was much higher in Flock A compared to others. The clinical manifestation included non-specific symptoms such as depression, inappetence, yellowish mucoid diarrhea, and lack of uniformity. At necropsy, typically, enlarged, pale, and friable livers were dominant, while sporadically lesions were recorded in the pancreas, kidneys, skeletal muscles, and lymphoid organs. The histopathological examination of liver samples showed multifocal inflammation, necrosis, and the presence of basophilic/ eosinophilic inclusion bodies in hepatocytes. In addition, the loss of the architecture of pancreatic lobules and the presence of fibrosis and foci of mononuclear cell aggregates were suggestive of chronic pancreatic inflammation. PCR analysis confirmed the presence of FAdV, belonging to species E, serotype FAdV-8b. Performance and financial calculations revealed that IBH increased Feed Conversion Ratio (FCR), feed cost/chick as well as feed cost/kg live weight, whereas the Livability (%) and the European Production Efficiency Factor (EPEF) were decreased in the most severely affected flocks (Flock A). This study is the first report of the detection and identification of FAdV serotypes associated with IBH in commercial broiler flocks in Greece. However, there is still a lack of information about the circulating FAdV serotypes in the country, and therefore epidemiological studies are needed to establish control strategies for IBH

Report on the First African Swine Fever Case in Greece

African swine fever (ASF) poses a major threat to swine health and welfare worldwide. After several European countries have reported cases of ASF, Greece confirmed officially the first positive case on 5 February 2020. The owner of a backyard farm in Nikoklia, a village in Serres regional unit, Central Macedonia, reported a loss of appetite, weakness, dyspnea, and the sudden death of 6 domestic pigs. Necropsy was performed in one gilt and findings were compatible with acute to subacute septicemic disease. Predominantly, hyperemic enlargement of spleen and lymph node enlargement and/or hemorrhage were observed. Description of vague clinical signs by the farmer suggested a limited resemblance to ASF-acute infection. However, the disease could not be ruled out once septicemic condition including splenomegaly, was diagnosed macroscopically at necropsy. In addition, considering the farm’s location near to ASF protection zones, a further diagnostic investigation followed. Confirmation of the disease was obtained using a series of diagnostic tests on several tissue samples. Further clinical, molecular, and epidemiologic evaluation of the farm was performed. According to the contingency plan, authorities euthanized all 31 pigs on the farm, whilst blood testing revealed ASF virus infection. Further emergency measures were implemented to contain the spread of the disease

First Detection and Identification of FAdV-8b as the Causative Agent of an Outbreak of Inclusion Body Hepatitis in a Commercial Broiler Farm in Greece

Inclusion body hepatitis (IBH) is an economically important disease of chickens, with a worldwide distribution, caused by Fowl Aviadenoviruses (FAdVs). Currently, the increased number of cases, the virulence of the isolate strains, as well as the lack of cross-species protection highlight that detailed in-field data are fundamental for the development of successful control strategies. This case report provides a detailed clinicopathological investigation of an unusual IBH outbreak in a commercial broiler farm in the region of Macedonia, Greece. The farm consisted of 64,000 birds, originated from the same breeder stock and placed in three different houses (Flock A–C). At 20 days of age, a sudden increase in daily mortality was recorded in Flock A. It is worth mentioning that, although all flocks were serologically (indirect ELISA) and molecularly (RT-PCR) positive for FAdV, the mortality rate, attributed to IBH, was much higher in Flock A compared to others. The clinical manifestation included non-specific symptoms such as depression, inappetence, yellowish mucoid diarrhea, and lack of uniformity. At necropsy, typically, enlarged, pale, and friable livers were dominant, while sporadically lesions were recorded in the pancreas, kidneys, skeletal muscles, and lymphoid organs. The histopathological examination of liver samples showed multifocal inflammation, necrosis, and the presence of basophilic/ eosinophilic inclusion bodies in hepatocytes. In addition, the loss of the architecture of pancreatic lobules and the presence of fibrosis and foci of mononuclear cell aggregates were suggestive of chronic pancreatic inflammation. PCR analysis confirmed the presence of FAdV, belonging to species E, serotype FAdV-8b. Performance and financial calculations revealed that IBH increased Feed Conversion Ratio (FCR), feed cost/chick as well as feed cost/kg live weight, whereas the Livability (%) and the European Production Efficiency Factor (EPEF) were decreased in the most severely affected flocks (Flock A). This study is the first report of the detection and identification of FAdV serotypes associated with IBH in commercial broiler flocks in Greece. However, there is still a lack of information about the circulating FAdV serotypes in the country, and therefore epidemiological studies are needed to establish control strategies for IBH

Investigation of the Effect of Three Commercial Water Acidifiers on the Performance, Gut Health, and <i>Campylobacter jejuni</i> Colonization in Experimentally Challenged Broiler Chicks

This study investigated the effect of three commercial water acidifiers on the performance, gut health, and C. jejuni colonization in experimentally challenged broiler chicks. A total of 192 one-day-old broiler chicks (Ross 308®) were randomly allocated into 6 treatment groups with 4 replicates according to the following experimental design: group A, birds were not challenged and received tap water; group B, birds were challenged and received tap water; groups C, D, E, and F, birds were challenged and received tap water treated with 0.1% v/v SPECTRON®, with 0.1–0.2% v/v ProPhorce™ SA Exclusive, with 0.1–0.2% v/v Premium acid, and with 0.1–0.2% v/v Salgard® Liquid, respectively. The continuous water acidification evoked undesirable effects on broilers’ performance and to an increased number of birds with ulcers and erosions in the oral cavity and the upper esophageal area. ProPhorce™ SA Exclusive and Premium acid significantly reduced the C. jejuni counts in the crop, whereas Salgard® Liquid significantly reduced the C. jejuni counts in the ceca of birds. At slaughter age, only Premium acid significantly reduced C. jejuni counts in the ceca of birds. All the tested products ameliorated the changes induced by C. jejuni infection in the pH in the ceca of birds. It can be concluded that besides the effectiveness of the tested products in controlling C. jejuni in broilers, their continuous application evoked undesirable effects on broilers’ performance, leading to the need to modify the dosage scheme in future investigations