Early hepatic and peritoneal changes and immune response in goats vaccinated with a recombinant glutathione transferase sigma class and challenged with Fasciola hepatica.

Changes and local immune response were evaluated in the peritoneal cell populations, duodenal lamina propria and liver from goats immunized with recombinant glutathione transferase sigma class (rFhGST-S1) during early stages of infection with Fasciola hepatica. Group 1 (n=7) was unimmunized and uninfected; group 2 (n=10) was immunized with adjuvant Quil A and infected; group 3 (n=10) was immunised with rFhGST-S1 and infected. Three goats from each group were killed at 7-9 days post-infection (dpi) to evaluate early changes and immune response. The remaining goats were killed at 15 weeks post-infection (wpi). rFhGST-S1 vaccination induced variable response: three goats showed low fluke burden at 15 wpi and two goats showed low hepatic damage at early infection stages. This response was associated to a severe infiltrate of eosinophils in peritoneal fluid and hepatic necrotic foci, high iNOS expression in peritoneal cells and abundant infiltrate of eosinophils surrounding hepatic migrating flukes. T lymphocyte subsets were found in the vicinity of necrotic areas but they were absent in the vicinity of migrating larvae. No significant variation for T cell subsets, except for CD4 and γδ T lymphocytes, that were higher in the Quil A group compared to the rFhGST-S1 group. Expression of IL4 and IFN-γ in the hepatic inflammatory infiltrates was very occasional.

Thyroid hormone concentrations differ between donkeys and horses.

REASONS FOR PERFORMING STUDY: Reference intervals for thyroid hormones (TH) concentrations have not been previously established for donkeys, leading to potential misdiagnosis of thyroid disease. OBJECTIVES: To determine the normal values of TH in healthy adult donkeys and compare them to TH values from healthy adult horses. METHODS: Thirty-eight healthy Andalusian donkeys and 19 healthy Andalusian horses from 2 different farms were used. Donkeys were divided into 3 age groups: <5, 5-10 and >11 years and into 2 gender groups. Serum concentrations of fT3, tT3, rT3, fT4 and tT4 were quantified by radioimmunoassay. All blood samples were collected the same day in the morning. None of the animals had received any treatment for 30 days prior to sampling or had any history of disease. Both farms were in close proximity and under similar management. Differences between groups were determined using a one-way ANOVA analysis followed by Fisher's LSD test. P<0.05 was considered significant. RESULTS: Serum TH concentrations were higher in donkeys than in horses (P<0.01). Donkeys <5 years had higher serum rT3, fT4 and tT4 concentrations than donkeys >5 years (P<0.05). Furthermore, older donkeys (>11 years) had lower serum fT3 and tT3 concentrations than younger donkeys' groups (<5 and 5-10 years, P<0.05). TH concentrations were not different between genders (fT3: P = 0.06; tT3: P = 0.08; rT3: P = 0.15; fT4: P = 0.89; and tT4: P = 0.19). CONCLUSIONS: Thyroid hormone concentrations are different between healthy adult donkeys and horses. POTENTIAL RELEVANCE: Establishing species-specific TH reference ranges is important when evaluating clinicopathologic data in equids in order to avoid the misdiagnosis of thyroid gland dysfunction. Further studies to elucidate the physiological mechanisms leading to these differences are warranted.

Early and late peritoneal and hepatic changes in goats immunized with recombinant cathepsin L1 and infected with Fasciola hepatica.

The aim of the present study was to study peritoneal and hepatic changes during early [7-9 days postinfection (dpi)] and late [15 weeks postinfection (wpi)] infection of goats immunized with recombinant F. hepatica pro cathepsin L1 (rCL1) in Quil A and challenged with Fasciola hepatica. Despite finding no significant reduction in fluke burdens between the control and immunized group, at 15 dpi the rCL1-vaccinated group showed significantly higher weight gain and reduced severity of hepatic lesions compared with the control group that received only Quil A. In the rCL1-vaccinated group, two of three goats sacrificed at 7-9 dpi had little hepatic damage and had a higher percentage of peritoneal eosinophils and elevated induced nitric oxide synthase (iNOS) expression in peritoneal cells than the goats from the control group. Moreover, while these two goats showed a heavy infiltration of eosinophils surrounding migrating flukes, the remaining animals examined at 7-9 dpi had no inflammatory infiltration surrounding migrating flukes. Two out of seven goats in the rCL1-vaccinated group had low fluke burdens and little hepatic damage at 15 wpi, suggesting an effective protective response in some of the vaccinated goats. This protective response did not correlate with peripheral eosinophilia or with serum titres of anti-rCL1 immunoglobulin (Ig) G. The results of the present work suggest that an eosinophil-mediated immune response plays a crucial role in the early effective host response against F. hepatica in goats. Adjuvants designed to increase cell-mediated immunity should be tested in future vaccine trials against F. hepatica.

Coagulation profiles of healthy Andalusian donkeys are different than those of healthy horses.

BACKGROUND: Coagulation disorders are frequently diagnosed, especially in hospitalized equidae, and result in increased morbidity and mortality. However, hemostatic reference intervals have not been established for donkeys yet. OBJECTIVES: To determine whether the most common coagulation parameters used in equine practice are different between healthy donkeys and horses. ANIMALS: Thirty-eight healthy donkeys and 29 healthy horses. METHODS: Blood samples were collected to assess both coagulation and fibrinolytic systems by determination of platelet count, fibrinogen concentration, clotting times (prothrombin time [PT] and activated partial thromboplastin time [aPTT]), fibrin degradation products (FDP) and D-Dimer concentrations. RESULTS: PT and aPTT in donkeys were significantly (P < .05) shorter than those of horses. In contrast, FDP and D-Dimer concentrations were significantly (P < .05) higher in donkeys than in horses. CONCLUSIONS AND CLINICAL IMPORTANCE: The coagulation parameters most commonly determined in equine practice are different in donkeys compared with horses. Thus, the use of normal reference ranges reported previously for healthy horses in donkeys might lead to a misdiagnosis of coagulopathy in healthy donkeys, and unnecessary treatments in sick donkeys. This is the first report of normal coagulation profile results in donkeys, and further studies are warranted to elucidate the physiological mechanisms of the differences observed between donkeys and horses.

Thoracic emphysematous lymphadenitis in a foal.

Emphysema of lymph nodes is a rare finding that has been described in different anatomical locations and related to specific diseases in different animal species. Herein is described a foal with Rhodococcus equi infection that presented with emphysema and granulomatous inflammation of the bronchial and mediastinal lymph nodes. This is the first report of emphysematous lymphadenitis in a horse.

Evaluation of hepatic damage and local immune response in goats immunized with native glutathione S-transferase of Fasciola hepatica.

Worm burden, hepatic damage and local cellular and humoral immune responses were assessed in goats immunized with glutathione-S-transferase and challenged with Fasciola hepatica. Infected but unimmunized and uninfected control groups were also studied. Hepatic damage was evaluated grossly and microscopically. Local immune response was evaluated by (1) microscopical examination of hepatic lymph nodes (HLNs); (2) analysis of the distribution of CD2(+), CD4(+), CD8(+), T-cell receptor gammadelta(+) lymphocytes and immunoglobulin (Ig) G(+) plasma cells; and (3) investigation of the distribution of cells expressing interleukin (IL)-4 and interferon (IFN)-gamma in the hepatic inflammatory infiltrates and HLNs. Immunized animals did not have significant reduction in fluke number, but there was significant (P<0.05) reduction of fluke size relative to the control groups. The lesions in the two infected groups were similar and consisted of fibrous perihepatitis and white tortuous tracts, mainly involving the left hepatic lobe. Microscopical lesions were similar in both infected groups and were typical of chronic fascioliosis. These included portal fibrosis, inflammatory infiltration with plasma cells, formation of lymphoid follicles, accumulation of haemosiderin-laden macrophages and granulomatous foci. Both infected groups had a marked local immune response characterized by infiltration of CD2(+), CD4(+) and CD8(+) T lymphocytes, and IgG(+) plasma cells in hepatic lesions and in HLNs. There was no expression of IL-4 or INF-gamma by cells in the hepatic inflammatory infiltrate, but expression of INF-gamma in HLNs was much lower than that of IL-4, suggesting an immune response dominated by T helper 2 cells.

Study of the local immune response to Fasciola hepatica in the liver and hepatic lymph nodes of goats immunised with a peptide of the Sm14 antigen.

The nature of the local immune response was assessed studying the distribution of CD2(+), CD4(+), CD8(+), gammadelta(+) T lymphocytes, IgM(+) B cells, IL-4(+) and IFN-gamma(+) cells in the liver and hepatic lymph nodes (HLN) of goats immunised with a synthetic peptide of the Sm14 antigen from Schistosoma mansoni and challenged with Fasciola hepatica. A morphometric study of HLN was also carried out in order to evaluate the hyperplasia of lymphoid follicles. Despite the decrease in fluke burdens found in the immunised group (45.9%) respect to the infected control group, this difference was not statistically significant due to the high individual variability. In liver, a significant increase of CD2(+), CD4(+), CD8(+), gammadelta(+) T lymphocytes was found in the infected groups respect to the uninfected control and in the infected control respect to the immunised group. HLN showed a significant enlargement due to the hyperplasia of lymphoid follicles and infiltration of CD2(+), CD4(+), CD8(+), gammadelta(+) T lymphocytes in both infected groups respect to the uninfected control, with no significant differences between the infected control and immunised group. IFN-gamma(+) lymphoid cells was absent or very occasional in HLN where the number of IL-4(+) cells was higher than that of IFN-gamma, suggesting a polarized Th2 response in immunised and in infected control group.

High iNOS expression in macrophages in canine leishmaniasis is associated with low intracellular parasite burden.

The expression of iNOS by macrophages in 33 dogs suffering from spontaneous leishmaniasis was analysed by immunohistochemistry in skin, liver and lymph nodes. A correlation study between the number of macrophages expressing iNOS and the number of macrophages containing leishmania amastigotes was carried out. Formalin-fixed paraffin-embedded tissue sections from the skin (28 cases), popliteal lymph nodes (8 cases) and liver (3 cases) of dogs of different age, sex and breed suffering from leishmaniasis were included in the study. Dogs were referred as positive for Leishmania spp by serology and the diagnosis was confirmed by demonstration of leishmania amastigotes within macrophages by histopathology. Tissue samples of skin (3 cases), popliteal lymph nodes (5 cases) and liver (3 cases) from dogs seronegative for leishmaniasis with no histopathological changes were included in the study as controls. The immunohistochemical study revealed that macrophages containing a high number of leishmania did not express iNOS. Correlation between the number of macrophages expressing iNOS and the number of macrophages containing leishmania amastigotes was assessed using the Spearman test. High expression of iNOS in macrophages was related with low number of leishmania amastigotes in macrophages in all cases (r=-0.47, p=0.002). These results suggest that iNOS expression by macrophages plays an important role during the control of Leishmania infection in dogs.

Concurrent aspergillosis and ascites with high mortality in a farm of growing broiler chickens.

Two flocks of broiler chickens aged 15 to 30 days presented respiratory signs such as dyspnea and up to 25% mortality. These were the only two flocks in the farm where a bed of sunflower shells was used instead of the rice-hull bedding used in other flocks. At necropsy, severe ascites, right heart hypertrophy, pulmonary congestion, and extensive multifocal granulomatous pneumonia were recorded. Histopathologic examination revealed chronic multifocal mycotic granulomatous pneumonia. Aspergillus fumigatus was identified by microbiologic study from pulmonary specimens. After disinfecting the floor and changing the bedding, no clinical signs were recorded in the farm. Severe chronic granulomatous pneumonia caused by A. fumigatus in the chickens of the present study may have caused hypoxia, leading to pulmonary hypertension, heart failure, and ascites.