Sero-epidemiological study of canine Leishmania spp. infection in the municipality of Alijó (Alto Douro, Portugal)

Visceral leishmaniosis caused by Leishmania infantum is a zoonotic disease in the Mediterranean basin. We report an epidemiological survey carried out in dogs from the municipality of Alijó in the endemic region of Alto Douro (north Portugal). Performance of the direct agglutination test (DAT) was assessed in 205 matching samples of blood collected on filter paper and serum. A high degree of agreement (97.6%; k = 0.83) was found between the results obtained from both types of samples. DAT was then used to test more blood on filter paper (B-FP) samples from other dogs of the same municipality. The detected sero-prevalence was 18.7% (288/1540), with values ranging from 0.0 to 81.1% in each of the 19 parishes of Alijó. Three distinct geographical zones of mean sero-prevalence could be defined: northwestern (2.5%), intermediate (11.4%) and southern (49.9%). No statistically significant difference was observed between male (19.1%) and female (17.8%) sero-prevalences (P = 0.560). Dogs of 9-11 years of age showed the highest sero-prevalence (28.4%), but all the other age-intervals (0-2, 3-5, 6-8 and 12-17 years) presented values (15.0-22.3%) not significantly different from the mean of the whole study population. Risk factors for canine Leishmania infection were age and geographical zone. Only 5.9% of the sero-positive animals had clinical signs of canine leishmaniosis and the overall prevalence of disease was 1.1%. This study validates the use of B-FP samples and confirms DAT as a simple and sensitive serological test to evaluate the level of canine Leishmania infection in areas of high sero-prevalence.     

Histopathological studies of visceralized Leishmania (Leishmania) amazonensis in mice experimentally infected

BALB/c, C57BL/6, and DBA/2 mice were subcutaneously infected in the left footpad by injecting 10(4) Leishmania (Leishmania) amazonensis amastigotes. Mice were sacrificed 20, 30, 40, 60 and 90 days post-infection. Fragments of liver, kidney, spleen, skin, and draining lymph node were collected for histological examination. Light microscopy showed that at 20 days after infection BALB/c mice presented discrete inflammatory infiltrates in the skin made up of eosinophils, lymphocytes, and rare parasitized macrophages. Ninety days post-infection, the dermis showed necrotic tissue, large numbers of mononuclear cells and vacuolated macrophages filled with amastigotes. Forty days post-infection, the draining lymph nodes showed hyperplastic germinal centers, increase of high endothelial venules and apoptosis in germinal center cells. After the first 3 months post-infection, the involvement of spleen, kidney and liver was discreet, being characterized by multifocal inflammatory infiltrates. Eight months after infection, the animals presented metastatic lesions in the contralateral footpad and nose. In deep dermis, there was remarkable proliferation of fibroblasts associated with collagen fibers. The liver showed multifocal granulomas and mononuclear infiltrate around the blood vessels, but no parasites were observed, except in one animal. In some mice there were immature cells of the hematopoietic lineage. Both BALB/c and C57BL/6 mice presented osteonecrosis, which is characterized by pycnotic osteocytes and empty lacunae at the point of inoculation and subsequently, replacement of this tissue by fibrous connective tissue and colonization of the bone marrow. A diffuse inflammatory process composed of mononuclear cells and rare parasites were seen in the kidneys. In one mouse, bone marrow cells were observed in the renal medulla along with where free amastigotes. DBA/2 mice developed a mild infection and they did not visceralize. In conclusion, our data demonstrates that in susceptible mice L. (L.) amazonensis, a causative agent of tegumentary leishmaniasis, causes pathological changes similar to those produced by Leishmania (L.) infantum in both humans and canids.     

Postnatal development of central corneal thickness in chicks of Gallus gallus domesticus

Objective To investigate the changes in corneal thickness that occur during maturation of the Gallus gallus domesticus chick eye over the first 450 days of life. Animals studied Twenty‐nine chicks, of which 12 were males and 17 were females. Procedures The central corneal thickness (CCT) was measured by ultrasonic pachymetry from hatch until 450 days of age. Segmented regression was applied to capture the two phases observed in the CCT plotted against age. Eye and gender were also included in the model. Results Mean CCT values initially decreased, with the lowest point being reached at around 12 days of age. CCT then gradually increased as the chick matured. At 70 days of age the animals have completed corneal development and reached the plateau value of 0.242 ± 0.0002 mm. CCT differences between gender or between left and right eyes were not statistically significant. Prediction equations for mean CCT according to the bird's age are presented. Conclusions There is an initial decrease in corneal thickness until approximately 12 days of age, which presumably mirrors maturation of corneal endothelial cell function. The pattern of changes in corneal thickness during the first phase of development of the chick CCT was similar to the one reported for dogs and humans. However, a unique feature of the development of CCT in chicks is that after reaching a plateau at 70 days corneal thickness did not significantly change over the remainder of the study period. Additionally, unlike in humans and dogs, there is no gender difference for corneal thickness in chicks.     

Canine Visceral Leishmaniosis in Anastácio,Mato Grosso do Sul State,Brazil

Canine visceral leishmaniosis (CVL) may be an important factor preceding human outbreaks of the disease. We report that the prevalence of canine visceral leishmaniosis infection has been increasing in recent years in Anastácio town, located in the central western region of Brazil. Serological investigations showed that 75.3% of dogs presented antibody titres ranging from 1/40 to 1/160 in the indirect immunofluorescence antibody test (IFAT). Bone marrow and lymph node aspirates provided positive cultures and furnished parasites for enzymological and serological typing in 42.5% and 41.1% of the cases, respectively. All the strains were typed as Leishmania (L.) chagasi. This is primarily a canine disease that spills over into the human population as a zoonosis. The study showed the epidemiological features of the infection in a region in which the problem of visceral leishmaniosis has been underestimated.     

Evaluation of Fertilizing Potential of Frozen-thawed dog Spermatozoa Diluted in ACP-106® using an In Vitro Sperm–Oocyte Interaction Assay

The aim of present study was to evaluate frozen canine semen with ACP-106 (Powder Coconut Water) using an in vitro sperm--oocyte interaction assay (SOIA). Ten ejaculates from five stud dogs were diluted in ACP-106 containing 20% egg yolk, submitted to cooling in a thermal box for 40 min and in a refrigerator for 30 min. After this period, a second dilution was performed using ACP-106 containing 20% egg yolk and 12% glycerol. Samples were thawed at 38 degrees C for 1 min. Post-thaw motility was evaluated by light microscopy and by using a computer aided semen analysis (CASA). Plasma membrane integrity and sperm morphology/acrosomal status were evaluated by fluorescent probes (C-FDA/PI) and Bengal Rose respectively. Moreover, frozen-thawed semen was analysed by a SOIA. Subjective post-thaw motility was 52.0 +/- 14.8% and it was significant higher than the total motility estimated by CASA (23.0 +/- 14.8%) because this system considered the egg yolk debris as immotile spermatozoa. Although normal sperm rate and acrosomal integrity evaluated by Bengal Rose stain was 89.6 +/- 3.1% and 94.3 +/- 3.1%, respectively, post-thaw percentage of intact plasma membrane was only 35.1 +/- 14.3%. Regarding SOIA, the percentage of interacted oocytes (bound, penetrated and bound and/or penetrated) was 75.3%. Using regression analysis, it was found significant relations between some CASA patterns and data for SOIA. In conclusion, the freezing-thawing procedure using ACP-106 was efficient for maintain the in vitro fertility potential of dog spermatozoa.     

Development and application of an enzyme-linked immunosorbent assay to detect antibodies against prevalent Salmonella serovars in swine in southern Brazil.

The implementation of Salmonella control programs in the pork production chain demands rapid and cost-effective methods to assess the prevalence of infection in pig herds. The objective of the present study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) based on S. Typhimurium lipopolysaccharides (LPS) to measure the prevalence of infection caused by Salmonella in swine herds. Coating antigen was produced by phenol extraction of S. Typhimurium culture. After standardization of ELISA test conditions, the assay was validated by testing serum samples on different animal categories: pigs orally inoculated with S. Typhimurium and sentinel animals in contact with them, naturally infected animals, colostrum-deprived piglets, and bacterin-immunized pigs. Seroconversion was observed in inoculated pigs (7 days postinfection [DPI]) and in the sentinels (21 DPI). Nonspecific reactions were not detected in the sera of colostrum-deprived animals. Serum samples from animals immunized with Salmonella Agona, Salmonella Derby, Salmonella Panama, and Salmonella Bredeney bacterins showed marked cross-reaction with the LPS from the serovar Typhimurium. Moreover, positive results obtained with the in-house ELISA were associated with Salmonella isolation in 75 infected pig herds. Comparisons with 2 commercial kits showed a linear correlation coefficient of 0.847 between the in-house ELISA and kit A and 0.922 with kit B but a low agreement in the qualitative results. In conclusion, the newly developed in-house ELISA based on S. Typhimurium LPS can be a useful tool to determine the intensity of Salmonella sp. infection in swine herds.     

Computed Tomography (Ct) of the Liver of the Dog by a Six-generation CT Scanner and Intravenous Contrast Medium

By computed tomography the liver has an intermediate degree of attenuation, with a CT value (HU) between 70 and 75. However, this number may vary according to the generation of the apparatus, the use of contrasts medium, the efficiency of the detector, etc. The purpose of the present work was to evaluate the liver of the dog and related structures by means of a six-generation spiral CT scanner (Toshiba Ex Vision [[Au: please provide manufacturers details for 'Toshiba Ex Vision': city, state code (if USA) and Country]]), and the previous injection of intravenous contrast medium via cephalic vein. Four half-breed mature dogs (4–6 years, 15–20 kg) were used, two males and two females. The dogs were anaesthetized and kept over a stretcher in sternal recumbency. To evaluate the liver two different CT windows with different window width and window level were applied: soft tissue window (WW 652; WL -34) and mediastinal-vascular window (WW 352; WL 220). The CT images obtained allowed an excellent resolution at the level of the hepatic lobules, the gall bladder, the porta vein, the hepatic artery, the caudal cava vein, etc. The attenuation shades of these structures were very similar in the two used windows, however a better contrast was obtained with the soft tissue window.     

Computed Tomography of the Mediastinum of the Dog by a Six-generation CT Scanner, Different Windows and Peroral and Intravenous Contrast Medium

The anatomical and clinical studies of computed tomography (CT) in the dog are still scarce. Particularly, there are few CT studies combining the use of rapid apparatus of the latest generation, the supply of contrast medium (digestive or intravenous) and the application of regional specific CT windows with different window width (WW) and window level (WL). The use of this CT methodology is particularly recommended in the evaluation of mediastinal masses, heart pathologies, etc. In this work the mediastinum of the dog was studied by using a sixth generation spiral CT scanner (Toshiba Ex Vision), belonging to the private Medical Institute of Radiology 'Irion' of Porto Alegre, Brazil. Four mixed-breed mature dogs (4–6 years, 15–20 kg) were used, two males and two females. The dogs were anaesthetized and kept at a maximum inspiration when getting the images. Previously, the urografin® contrast had been injected by peroral and intravenous (cephalic vein) via. Dogs were placed in a stretcher in sternal recumbency. Different CT windows were applied in order to increase the quality of the images and to obtain detailed attenuation shades of the mediastinum organs: soft tissue window (WW 652; WL -34), pulmonary window (WW 928; WL -680) and mediastinal-vascular window (WW 352; WL 220). The mediastinal space was studied craniocaudally from the level of the cranial cava vein, brachiocephalic trunk and left subclavian artery, to the caudal end of the lumbodiaphragmatic recess . The obtained images allowed a very good tomographic evidence of the great vessels, the heart, the thoracic portion of the trachea, the principal bronchi, the thoracic portion of the oesophagus, etc.     

Animal production and genetic resources in Guinea Bissau: II–Tombali province

A survey of the animal production systems and genetic resources was conducted in Tombali Province, Guinea Bissau. Animal owners and their families, village chiefs, shepherds and local officials were interviewed. The vast majority of the population is dedicated to very small-scale subsistence farming where animal ownership has an important role in both food supply, ceremonial events and as form of cash reserve. Animal production in the area is characterized by the existence of several ethnic groups: Balanta, Nalú, Sosso, Biafada and Fula. Only Balanta raise cattle (N'Dama and West African Shorthorn) and pig (crioulo breed) whereas all ethnic groups own goats (West African Dwarf), chickens and ducks. Sheep are limited to specific areas and ethnic groups. The survey is intended to serve as a basis to possible agricultural and animal production development projects in this area.