Septicemic salmonellosis in suckling piglets resulting from improper intramuscular administration of an oral vaccine.

We describe an unusual outbreak of mortality in suckling piglets following the misadministration of an oral vaccine against Salmonella Typhimurium and Salmonella Choleraesuis. Within 3-48 h of vaccination of a batch of ~700 piglets, ~300 developed marked swelling in the dorsal neck region, respiratory distress, fever, recumbency, and apathy. In total, ~100 died, and 4 were submitted for autopsy. Gross and microscopic lesions consisted of focally extensive areas of purple discoloration in the skin of the cervical region, associated with edema and hemorrhage in the subcutis and muscles. Additionally, there was interstitial pneumonia with marked interlobular edema and mild fibrinous pleuritis. Aerobic bacterial culture identified Salmonella Typhimurium (3 cases) and Salmonella Choleraesuis (1 case) in samples of skeletal muscle and lung and from pleural swab samples. Marked immunostaining against Salmonella spp. was observed in the skeletal muscle of the cervical region, as well as in blood vessels and macrophages from the lung, liver, spleen, and kidney. We concluded that inappropriate intramuscular administration of an oral vaccine against Salmonella resulted in septicemia and death in a batch of piglets.

Auricular and laryngeal chondritis in nursery and finishing pigs.

This work aimed to characterize the clinic-pathological presentation of an outbreak of auricular and laryngeal chondritis in pigs. Visits were made to pig farms, where the clinical history was obtained, and clinical and postmortem examinations were performed. In those farms, 3% to 4% of pigs presented otohematomas, which started in the nursery and extended to the finishing phase. Moreover, some finishing pigs presented with respiratory distress, initially characterized as inspiratory dyspnea, associated by an uncommon respiratory stridor and culminating in death. Grossly, nursery piglets had enlarged ears, and on the cut surface, the cartilage was fragmented and associated with blood clots. In the finishing phase, in addition to auricular lesions, the epiglottis and arytenoid cartilages were thickened and distorted, which partially occluded the lumen. Microscopically, the laryngeal and auricular cartilages were fragmented, displayed a loss of matrix basophilia, and were surrounded by lymphohistiocytic inflammatory infiltrate, with occasional multinucleated giant cells and fibrosis. The lesions exclusively affected elastic cartilages. The disease in finishing pigs led to increased mortality and was a differential diagnosis to respiratory challenges. It was not possible to determine the factor that triggered this condition; however, a nutritional association is suspected. To the authors' knowledge, this is the first report of primary auricular and laryngeal chondritis in pigs.

Pasteurella multocida polyserositis in growing-finishing pigs.

Pasteurella multocida is the main secondary bacterium isolated from cases of swine pneumonia. Although highly pathogenic strains of P. multocida have been associated with primary septic lesions and polyserositis in pigs, studies on this pathological presentation in naturally occurring cases are limited. The aim of this work was to characterize the clinical, pathological and molecular findings in cases of P. multocida polyserositis in growing-finishing pigs in a commercial farm in Brazil. The mean age of 17 investigated pigs was 120 days. Clinically, the disease was acute (11/17), with clinical signs of dyspnoea and apathy. Sudden death occurred in some animals (6/17). The main gross findings included fibrinous serositis affecting the abdominal and thoracic cavities (17/17), fibrinous pericarditis (15/17), marked cranioventral pulmonary consolidation (17/17) and splenic infarcts (3/17). P. multocida was isolated in all cases from systemic sites, including the pericardial sac and abdominal exudate. Molecular typing of genus and species was performed on four isolates, and all were characterized as P. multocida type A. Another five isolates were positive for the pathogenicity marker gene pfhA by polymerase chain reaction. This study reinforces the role of P. multocida as a cause of polyserositis in growing-finishing pigs.

Nutritional chondrodysplasia in cattle in Brazil.

In this work, we investigated cases of birth of calves with congenital defects in a farm in Southern Brazil. Only calves born from heifers were affected, and the disease occurred in both crossbred and purebred calves. Three necropsies were performed, tissues were collected for histopathology, and samples of liver of calves, blood serum, and food provided for cows and heifers were collected to quantify the levels of the minerals: manganese, copper, and zinc. The calves were born weak, with disproportionate dwarfism, limb deformities, and enlarged joints. Heads were shortened and domed. Long bones had a shortened diaphysis and a normal-sized epiphysis, when compared to the control. In one of the cases, there were white-yellowish lines on the metaphyseal surface of the epiphyseal plate. Histopathology of growth plates revealed premature closure, disarrangement of chondrocyte columns, and collapse of primary spongiosa. These findings supported a diagnosis of chondrodysplasia. Liver manganese levels were under the reference values in the three calves. Food analysis revealed insufficient levels of manganese in the diet of heifers, especially in sorghum silage, which was provided as the main source of food for the category in some periods. Approximately 6 months after the diet was changed, the problem ceased and only normal calves continued to be born. Our findings allowed to conclude the diagnosis of chondrodysplasia of nutritional origin and reinforce the thesis that manganese is the mineral deficient in these cases.

Eosinophilic Granulomatous Myocarditis in Two Pigs.

Eosinophilic myocarditis is a human condition that has been rarely documented in animals. We now report two unrelated porcine cases of idiopathic eosinophilic granulomatous myocarditis that resembled the human disease and which were associated with sudden death. The most relevant gross finding in both cases was marked cardiomegaly, accompanied by raised, multifocal to coalescent small white nodules (1-2 mm) and poorly demarcated multifocal pale areas in the epicardium. Histologically, there were multifocal to coalescent areas of cardiomyocyte loss with replacement by an intense inflammatory infiltrate of eosinophils and epithelioid macrophages, and proliferation of fibrous connective tissue. Immunohistochemistry for porcine circovirus type 2 (PCV2) and Toxoplasma gondii, in-situ hybridization and quantitative polymerase chain reaction tests for PCV2 and porcine circovirus type 3 and aerobic bacterial culture on myocardium samples were negative.

Pathological and Microbiological Findings in Fatal Cases of Salmonellosis in Captive Bothrops Snakes in Southern Brazil.

Salmonella spp. are gram-negative commensal bacteria of vertebrates, including reptiles. Infected snakes may be asymptomatic or manifest clinical disease and death, especially after stressful events. Salmonellosis was diagnosed in 10 captive snakes from the Bothrops genus. The most frequent changes were emaciation (8/10), fibrinonecrotic or granulomatous hepatitis (8/9), fibrinonecrotic or granulomatous enterocolitis (8/9), necrotic and heterophilic myocarditis (2/10), fibrinonecrotic or granulomatous pancreatitis (2/5), fibrinoheterophilic osteomyelitis (1/10), fibrinous and pyogranulomatous pericarditis (1/10) and granulomatous splenitis (1/6). Salmonella enterica was isolated from six cases. The subspecies identified were arizonae (3/6), diarizonae (1/6) and houtenae (1/6), in addition to the serotype Typhimurium (1/6). In cases without isolation, there was immunolabelling of Salmonella spp. in intestinal (3/4), hepatic (1/4) and cardiac (1/4) lesions.

Comparison of immunohistochemical profiles of ovarian germ cells in dysgerminomas of a captive maned wolf and domestic dogs.

We characterized the immunohistochemical expression profiles of dysgerminomas from a 16-y-old maned wolf and 13 domestic dogs using the following biomarkers: Sal-like protein 4 (SALL4), octamer-binding transcription factor 3/4 (OCT3/4), placental alkaline phosphatase (PLAP), c-kit, and vimentin. The maned wolf had nonspecific and long-standing clinical signs of lethargy, anorexia, and weight loss, and was euthanized because of poor prognosis. At autopsy, the left ovary was effaced by a 12 × 8 × 6 cm mass, comprised of anaplastic cells with a mitotic count of 20 mitoses in 10 high power fields. Dysgerminomas from 7 of 13 domestic dogs had nuclear expression of SALL4. Dysgerminomas from the maned wolf and 2 domestic dogs had both nuclear and cytoplasmic expression of SALL4. Cytoplasmic expression of PLAP and OCT3/4 was present in dysgerminomas from the maned wolf and 3 (PLAP) or 4 (OCT3/4) domestic dogs. All dysgerminomas expressed vimentin. Membranous c-kit expression was rare in the dysgerminoma from the maned wolf, and variable in dysgerminomas from 4 domestic dogs. A dysgerminoma from a domestic dog had cytoplasmic expression of c-kit. SALL4 is a useful marker to confirm germ cell origin of dysgerminoma in canids.

Causes of death in growing-finishing pigs in two technified farms in southern Brazil / Causas de morte em suínos de crescimento e terminação em duas granjas tecnificadas no Sul do Brasil

The aim of this study was to investigate the main causes of death in growing-finishing pigs in southern Brazil. During a one-year period (from 2018 to 2019), two industrial pig herds (18 and 20 thousand pigs each farm) in southern Brazil were monitored along the four seasons of the year (12 days per season on each farm), in order to perform necropsies of all pigs that died in that period. The two farms had an average monthly mortality rate ranging from 0.94 to 3.93% in the evaluated months. At necropsy, tissues were collected, fixed in 10% formalin solution and processed routinely for histopathological examination. When necessary, samples were sent for bacterial culture and PCR to identify etiologic agents. A total of 601 necropsies were performed, with 94.9% of conclusive diagnoses. Infectious diseases corresponded to 64.4% of conclusive diagnosis and non-infectious diseases to 35.6%. The most prevalent causes of death were: pneumonia (33%), gastric ulcers (15.4%), circovirosis (9.9%), systemic bacterial embolism (5.4%), polyserositis (4.4%), dilated cardiomyopathy and torsion of abdominal organs (4.3% each), and bacterial pericarditis (3.4%). Regarding pneumonias (199/601), the main agents identified in these cases were Pasteurella multocida, Influenza A virus and Mycoplasma hyopneumoniae, mainly in associations.(AU)

O objetivo do presente trabalho foi investigar as principais causas de morte de suínos em fase de crescimento e terminação no Sul do Brasil. Durante o período de um ano (entre 2018 e 2019), duas granjas tecnificadas de suínos no Sul do Brasil foram acompanhadas nas quatro estações (12 dias por estação em cada granja), para realização de necropsias dos suínos que morreram nesse período. As duas propriedades apresentavam mortalidade mensal média entre 0,94 e 3,93% nos meses avaliados. Na necropsia, amostras de órgãos foram colhidas, fixadas em formol 10% e processadas rotineiramente para o exame histopatológico. Quando necessário, amostras foram enviadas para o cultivo bacteriano e PCR para identificação de agentes etiológicos. Foram realizadas um total de 601 necropsias, com 94,9% de diagnósticos conclusivos. As doenças infecciosas corresponderam a 64,4% dos diagnósticos conclusivos e as não infecciosas a 35,6%. As principais causas de morte foram: pneumonias (33%), úlcera gástrica (15,4%), circovirose (9,9%), embolia bacteriana sistêmica (5,4%), polisserosite (4,4%), cardiomiopatia dilatada e torção de órgãos abdominais (4,3% cada) e pericardite bacteriana (3,4%). Com relação às pneumonias (199/601), os principais agentes associadas as lesões foram Pasteurella multocida, vírus da Influenza A e Mycoplasma hyopneumoniae, principalmente associados entre si.(AU)

Effects of fed mycotoxin contaminated diets supplemented with spray-dried porcine plasma on cholinergic response and behavior in piglets.

The aim of this study was to evaluate the effect of spray-dried porcine plasma (SDPP) supplementation on cholinesterase enzymes and its relationship with animal behavior of weaning piglets exposed to mycotoxin contaminated diets. To achieve these objectives, two experimental design approaches were used. Male piglets (7.15±0.61kg) were allocated in four groups: CTL group received a regular diet; SDPP group received a regular diet and 6% SDPP; MYC group received a diet containing desired contamination of 210 µg/kg aflatoxins and 6.690 µg/kg fumonisins; group MYC+SDPP received 253 µg/kg aflatoxins, 6930 µg/kg fumonisins and 6% SDPP. The animals treated with mycotoxin co-contaminated diets showed an increase in AChE and BChE activities in peripheral system (MYC) when compared to control (CTL). Furthermore, supplementation with SDPP (MYC+SDPP group) prevented the mycotoxin-related reduction of AChE in blood and brain. Behavioral tests showed that sleeping and resting behaviors were more often observed in the MYC group; this group also fed fewer times when compared to the other groups, characterizing the deleterious effect of mycotoxins. Taken together, the data suggest changes in AChE and BChE activities may indicate alterations in cholinergic neurotransmission and consequently in the behavior of piglets.

PEGylated meloxicam-loaded nanocapsules reverse in vitro damage on caspase activity and do not induce toxicity in cultured human lymphocytes and mice.

Meloxicam is an anti-inflammatory drug that has a potential protective effect in many common diseases. However, this molecule is quickly eliminated from the body due to it short half-life. One way to overcome this problem is to incorporate meloxicam into lipid-core nanocapsules which may increase it anti-inflammatory effects. In view of this, the objective of this work was to evaluate the potential toxicity and safety of these novel nanomaterials both in vitro and in vivo. Here, we evaluated the effects of uncoated meloxicam-loaded nanocapsules (M-NC), uncoated and not loaded with meloxicam or blank (B-NC), PEGylated meloxicam-loaded lipid-core nanocapsules (M-NCPEG), blank PEGylated lipid-core nanocapsules (B-NCPEG) and free meloxicam (M-F) in vitro through the analysis of cell viability, caspase activity assays and gene expression of perforin and granzyme B. Meanwhile, the in vivo safety was assessed using C57BL/6 mice that received nanocapsules for seven days. Thus, no change in cell viability was observed after treatments. Furthermore, M-NC, M-NCPEG and M-F groups reversed the damage caused by H2O2 on caspase-1, 3 and 8 activities. Overall, in vivo results showed a safe profile of these nanocapsules including hematological, biochemical, histological and genotoxicity analysis. In conclusion, we observed that meloxicam nanocapsules present a safe profile to use in future studies with this experimental protocol and partially reverse in vitro damage caused by H2O2.

Ectonucleotidase and adenosine deaminase as inflammatory marker in dairy cows naturally infected by Dictyocaulus viviparus.

The aim of this study was to evaluate the influence of dictyocaulosis (mild or severe) on enzymes of NTPDase, 5'-nucleotidase, and adenosine deaminase (ADA) of dairy cows naturally infected by Dictyocaulus viviparus. Blood and faeces were collected from 22 dairy cows of the same farm to evaluate NTPDase (ATP and ADP substrate), 5'-nucleotidase, and ADA activities on days 0 (pre-treatment) and 10 (post-treatment). Seric activities of NTPDase (ATP substrate), 5'-nucleotidase, and ADA were lower (P<0.05) in D. viviparus infected animals compared to uninfected cows. The number of D. viviparus larvae per gram of faeces varied among the animals, and they showed different degrees of severity according to respiratory clinical signs of the disease (cough and nasal discharge). Later, these cows were divided into two groups: those with mild (n=10) and severe (n=12) disease. Cows with severe disease showed higher NTPDase activity (ATP substrate) than those with mild disease (P≤0.05). The opposite occurred with NTPDase (ADP substrate), 5'-nucleotidase, and ADA in cows with severe disease, that is, the enzymatic activity of these seric enzymes significantly decreased (P≤0.05) compared to animals with mild disease. Infected animals showed reduced NTPDase activity (ATP and ADP substrate) after treatment. No enzymatic changes were observed for 5'-nucleotidase, and ADA pre- and post-treatment (P>0.05). Based on these results, we conclude that dictyocaulosis alters NTPDase, 5'-nucleotidase, and ADA activities of cow naturally infected by the parasite, in consequence the enzymes act as inflammatory markers.

Activities of ectonucleotidases and adenosine deaminase in platelets of cattle experimentally infected by Fasciola hepatica.

The enzymatic activities of NTPDase, 5'-nucleotidase and adenosine deaminase (ADA) are important in regulating the concentration of adenine nucleotides, molecules known to be involved on platelet aggregation. Fasciolosis causes coagulation disorders that have not been completely elucidated. Taking into consideration the association between the purinergic system and hemostasis, this study aimed to evaluate the enzymatic activities of NTPDase (hydrolyze ATP and ADP), 5'-nucleotidase (hydrolyze AMP) and ADA (deamination of adenosine) in platelets from cattle experimentally infected by Fasciola hepatica on days 20, 40, 60 and 80 post-infection (PI). For this study, 10 healthy Friesian steers were separated into two groups: the group A (n = 5) was used as uninfected control, and the group B was composed of steers experimentally infected by F. hepatica (n = 5). The number of platelets did not differ between groups in the periods evaluated. Reduction of NTPDase (p < 0.05) hydrolysing ATP (days 20, 40 and 60 PI), and ADP (days 40, 60 and 80 PI), and on 5'-nucleotidase hydrolyzing AMP (days 40 and 60 PI) was observed. A reduction (p < 0.05) in ADA activity on day 20 PI, as well as an increase (p < 0.05) in ADA activity on days 40 and 60 PI was observed when compared to the control. Based on these results, we can conclude that ATP, ADP and AMP hydrolysis and adenosine deamination were altered in platelets of cattle infected by F. hepatica. Considering the importance of the purinergic system in hemostasis, it is believed that those changes may contribute to the coagulation impairment observed in acute fasciolosis described in the literature.

Oxidative stress and changes in adenosine deaminase activity of cattle experimentally infected by Fasciola hepatica.

The aim of this study was to evaluate the oxidative stress in serum and liver and adenosine deaminase (ADA) activity of cattle experimentally infected by Fasciola hepatica. The group A consisted of five healthy animals (uninfected), and the group B was composed of five animals orally infected with 200 metacercariae of F. hepatica. On days 20, 40, 60 and 80 post-infection (PI) serum was collected to measure oxidative stress variables. On day 100 PI, animals were humanely euthanized and liver samples were collected. Infected animals showed lower (P < 0·05) seric ADA activities on days 40 and 60 PI but higher (P < 0·05) in the liver tissue compared with uninfected animals. Seric and hepatic reactive oxygen species (ROS) were higher (P < 0·05) in infected compared with uninfected animals. Hepatic thiobarbituric acid reactive substances were higher (P < 0·05) in infected animals. Catalase and glutathione S-transferase activities were lower in liver tissue of infected animals, while glutathione peroxidase was higher compared with uninfected (P < 0·05). In summary, we conclude that oxidative stress occurs in cattle experimentally infected by F. hepatica, mainly due to excessive ROS production in the course of fasciolosis, contributing to hepatic damage, and that increased in hepatic ADA activity may contribute to the inflammatory process.

Immune protection conferred by recombinant MRLC (myosin regulatory light chain) antigen in TiterMax Gold® adjuvant against experimental fasciolosis in rats.

Protection against experimental fasciolosis in rats immunized with recombinant myosin regulatory light chain (MRLC) in TiterMax Gold® adjuvant was assessed. The experimental trial consisted of four groups of 15 animals; group 1 was unimmunized and infected, group 2 was immunized with MRLC in adjuvant and infected, group 3 was infected and immunized with adjuvant only and group 4 was unimmunized and uninfected. Immunization with MRLC in TiterMax Gold® adjuvant (group 2) induced a reduction in fluke burdens of 51.0% (p<0.001) when compared with the adjuvant control group, and 61.5% (p<0.001) when compared with the unimmunized infected controls. There was a reduction in fecal egg output in group 2 of 44.8% and 37.3% compared with group 1 and group 3, respectively; although this difference was not statistically significant. Measurement of cytokine levels revealed higher levels of TNF-alpha and IL-2 as well as lower levels of IL-4 in group 2 during the chronic stage of infection (p<0.05), along with higher levels of IFN-gamma during early stages of infection (p<0.05). These results suggest a mixed Th1/Th2 phenotype immune response; however predominance of Th1 cytokines was observed. Levels of anti-MRLC serum IgG in group 2 were significantly higher than controls at the time of euthanasia (p<0.05). This is the first report of immunization with recombinant MRLC in rats, demonstrating that this antigen significantly reduces fluke burdens, increases the Th1 immune response and encourages further studies to improve the vaccine's efficacy.

Dictyocaulosis in dairy cows in Brazil: an epidemiological, clinical-pathological and therapeutic approach.

An outbreak of severe parasitic pneumonia caused by Dictyocaulus viviparus was diagnosed in adult dairy cows in the municipality of Arabutã, Southern Brazil. The total morbidity in the herd was 71.9%, and the morbidity amongst adult lactating cattle was 100%. The main clinical signs observed were dyspnea, tachypnea, nasal discharge, decreased milk production, and cough. A necropsy was conducted on one animal in order to establish the diagnosis. The herd had been treated previously with levamisole; however, clinical signs persisted and became worse. After treatment with eprinomectin the severity of clinical signs decreased, and the respiratory condition subsequently disappeared. It is believed that the high morbidity presented in this outbreak is related to epidemiological factors, such as increased rainfall in 2014 and 2015, associated with low immunity of the herd. This is the first report of dictyocaulosis in adult dairy cattle in Brazil. Furthermore, it describes an outbreak presenting very high morbidity.

Seric and hepatic NTPDase and 5' nucleotidase activities of rats experimentally infected by Fasciola hepatica.

The enzymatic activities of NTPDase and 5'nucleotidase are important to regulate the concentration of adenine nucleotides, known molecules involved in many physiological functions. Therefore, the objective of this study was to evaluate the activity of NTPDase and 5'nucleotidase in serum and liver tissue of rats infected by Fasciola hepatica. Rats were divided into two groups: uninfected control and infected. NTPDase activity for adenosine triphosphate (ATP) and ADP substrates in the liver was higher compared with the control group at 15 days post-infection (PI), while seric activity was lower. In addition, seric and hepatic samples did not show changes for 5'nucleotidase activity at this time. On the other hand, either NTPDase or 5'nucleotidase activities in liver homogenate and serum were higher at 87 days PI. Early in the infection, low NTPDase activity maintains an increase of ATP in the bloodstream in order to activate host immune response, while in hepatic tissue it decreases extracellular ATP to maintain a low inflammatory response in the tissue. As stated, higher NTPDase and 5'nucleotidase activities 87 days after infection in serum and tissue, probably results on an increased concentration of adenosine molecule which stimulates a Th2 immune response. Thus, it is possible to conclude that F. hepatica infections lead to different levels of nucleotide degradation when considering the two stages of infection studied, which influences the inflammatory and pathological processes developed by the purinergic system.

Oxidative stress associated with pathological lesions in the liver of rats experimentally infected by Fasciola hepatica.

The aim of this study was to analyze the antioxidant status and oxidative profile in serum and liver of rats experimentally infected with Fasciola hepatica and its relationship with pathological findings. Twenty-four rats were divided into two groups: group A consisted of 12 healthy rats and group B of 12 rats infected orally with 20 metacercaria of F. hepatica. At days 20 and 150 post-infection (PI), blood and liver samples of six animals from each group were collected. The protein oxidation (AOPP technique: advanced oxidation protein products) and antioxidants (FRAP technique: ferric reducing antioxidant power) levels were measured in serum and liver. Furthermore, nitrite/nitrate (NOx) levels and lipid peroxidation (TBARS technique: thiobarbituric acid reactive substances) were measured in liver. AOPP and FRAP levels were increased (P < 0.05) in serum and liver of infected animals in acute and chronic infection when compared with healthy animals. The same occurred with TBARS and NOx levels in the liver (P < 0.05). Histopathology revealed periportal fibrous hepatitis, composed of an abundant inflammatory infiltrate in portal spaces on infected animals, as well as bile duct hyperplasia. The results found seem to be related to the host free radical production demonstrated in serum samples and liver due to the parasite infection.