Imaging studies of the hindlimbs of pacas (Cuniculus paca) bred in captivity.

OBJECTIVE: To evaluate the hindlimbs of pacas bred in captivity using radiographic and computed tomography (CT) studies. ANIMALS: Nine mature pacas (Cuniculus paca) 5.9-8.2 kg in body weight. METHODS: Radiographical aspects of the bones of the hindlimbs were evaluated, and the Norberg angle and inclination angle were measured for each hindlimb. Anteversion angle were measured in CT examination. RESULTS: The bone anatomy of the hindlimb of the paca was similar to that of the guinea pig, apart from two lunulae and a single fabella (lateral) which were observed. The Norberg angle had mean value of 130.56º ± 3.81 without any significant difference between testers. Inclination angles ranged from 142.44º ± 4.82 to 145.44º ± 4.09 by Hauptman's method, and from 144.94º ± 3.13 to 148.22º ± 3.25 by Montavon's method, for right and left hindlimbs respectively. Average values for the anteversion angles measured with CT ranged from 28.56º ± 5.56 to 32.91º ± 2.62. CLINICAL SIGNIFICANCE: The data may be used in future studies comparing the paca to other rodent species. In addition, the paca could be used as an animal model in orthopaedic research.

Toxoplasma gondii: congenital transmission in a hamster model.

The objective of the research was to test the hamster for a model of transmission of congenital toxoplasmosis. A non-invasive method for the diagnosis of pregnancy in hamsters was designed, with a specificity and a sensitivity of 70.2 and 94.7%, respectively (n=168). Of 32 females with a chronic toxoplasma infection, 3 transmitted Toxoplasma congenitally during their first pregnancy, but not during the subsequent pregnancy. Congenital transmission rates of infections initiated during pregnancy with 2 stages of 2 strains of Toxoplasma were in the range of 33 to 100% of the 76 females inoculated. Only 1 of 17 females transmitted the parasite exclusively via milk. It was concluded that the hamster is a promising species for a model of transmission of congenital toxoplasmosis.

Bone morphology of the hind limbs in two caviomorph rodents.

In order to evaluate the hind limbs of caviomorph rodents a descriptive analysis of the Cuniculus paca (Linnaeus, 1766) and Hydrochoerus hydrochaeris (Linnaeus, 1766) was performed using anatomical specimens, radiography, computed tomography (CT) and full-coloured prototype models to generate bone anatomy data. The appendicular skeleton of the two largest rodents of Neotropical America was compared with the previously reported anatomical features of Rattus norvegicus (Berkenhout, 1769) and domestic Cavia porcellus (Linnaeus, 1758). The structures were analyzed macroscopically and particular findings of each species reported. Features including the presence of articular fibular projection and lunulae were observed in the stifle joint of all rodents. Imaging aided in anatomical description and, specifically in the identification of bone structures in Cuniculus paca and Hydrochoerus hydrochaeris. The imaging findings were correlated with the anatomical structures observed. The data may be used in future studies comparing these animals to other rodents and mammalian species.

Kinematic analysis in healthy and hip-dysplastic German Shepherd dogs.

This study investigated kinematic patterns in clinically normal German Shepherd dogs (GSDs) compared to those with hip dysplasia and with no clinical signs of lameness. Two groups of GSDs, including 10 clinically healthy dogs (G1) and 10 with hip dysplasia (G2), were trotted on a treadmill at a constant speed. Kinematic data were collected by a 3-camera system and analysed by a motion-analysis program. Flexion and extension joint angles and angular velocities were determined for the shoulder, elbow, carpal, hip, stifle, and tarsal joints. Within each group, the differences between the right and left limbs in all kinematic variables were not significant. Minimum angle, angular displacement and minimum angular velocity did not differ between groups. Significant differences were observed in the maximum angular velocity and maximum angle of the hip joint (dysplastic>healthy), and in the maximum angular velocity of the carpal joint (healthy>dysplastic). It was concluded that, when trotting on a treadmill, dysplastic dogs with no signs of lameness may present joint kinematic alterations in the hind as well as the forelimbs.

Toxoplasma gondii in free-ranging wild small felids from Brazil: molecular detection and genotypic characterization.

Brazil harbors the largest number of wild Neotropical felid species, with ten of the twelve species recorded in the American continent. Although these animals are considered to be definitive hosts for Toxoplasma gondii, there are few descriptions of the parasite in these species. Here, we performed a molecular detection of T. gondii by amplification of the marker ITS-1 from tissue samples obtained from 90 free-ranging wild small Neotropical felids from Rio Grande do Sul - Brazil. Of the sampled animals, 34.4% (n=31) were positive including the species Puma yagouaroundi - jaguarondi (9/22), Leopardus geoffroyi - Geoffroy's cat (6/22), Leopardus tigrinus - oncilla (8/28), Leopardus wiedii - margay (6/10), Leopardus pardalis - ocelot (1/1) and Leopardus colocolo - Pampas cat (1/7). Toxoplasma DNA was detected with a frequency of 14.6% (63/433) in primary samples of tongue (16/56), brain (8/43), skeletal muscle (15/83), heart (7/63), diaphragm (3/56), vitreous humor (2/44), eye muscle (6/44) and eyeball (6/44). Multilocus PCR-RFLP genotyping of eleven small Neotropical felids using the molecular markers SAG1, 5'3'SAG2, alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3 allowed the partial characterization of eight genotypes. We fully characterized two new genotypes that have not been described previously in Brazil (Lw#31Tn from L. wiedii and Py#21Sm from P. yagouaroundi) and one genotype Py#56Br from P. yagouaroundi that has been described previously in isolates from cats, dogs and capybaras from São Paulo state. This study constitutes the first detection and genotypic characterization of T. gondii in free-ranging felids in Brazil, demonstrating the occurrence of the parasite in wild populations and suggesting its potential transmissibility to humans and other domestic and wild animals.

Protection in a hamster model of congenital toxoplasmosis.

Almost uniform protection against congenital toxoplasmosis initiated by inoculations with cysts and oocysts of the parasite was seen in the hamster model, among strains of different genotypes. Because the RH immunization prior to pregnancy has to be controlled with medication for most of the hamsters to survive, and also some congenital transmission of Toxoplasma was observed during the chronic stage of the infection, the hamster is considered less practical than the rat and the BALB/c mouse models. It is concluded that the hamster model closely resembles protection against congenital infection in nature, where most of the pregnant women and ewes that experienced a toxoplasma infection previously, protect their fetuses against an infection with the parasite during pregnancy.

Diagnóstico de hemoparasitose através da técnica de distensäo de gota de coágulo sanguíneo / Diagnosis of hemoparasitosis trough the spread-smear technique using a drop of blood clot

O desempenho da técnica de distensäo de Gota do Coágulo de sangue, entre as coloraçöes de Giemsa diluído e puro, é avaliado em relaçäo à possibilidade de observaçäo dos elementos figurados e da presença de Babesia bovis, Babesia bigemina e Anaplasma marginale. Utilizou-se um bovino, com 6 meses de idade inoculado com os agentes da Tristeza Parasitária, como doador das amostras de sangue. A técnica permitiu a observaçäo dos eritrócitos, leucócitos e dos hemoparasitas

Utilizaçäo do esfregaço de coágulo sanguíneo para o diagnóstico de Babesia e Anaplasma em bovinos / Utilization of blood clot smear for diagnosis of Babesia and Anaplasma in cattle

O desempenho da técnica de esfregaço de fragmento de coágulo de sangue, com as coloraçöes de Giemsa diluído e puro, é avaliado em relaçäo à apresentaçäo dos elementos figurados e na determinaçäo de parasitemia por Babesia bovis, B. bigemina e Anaplasma marginale. Utilizou-se um bovino, seis meses de idade e inoculado com os agentes da tristeza parasitária bovina como doador das amostras de coágulo. A técnica mostrou-se adequada ao diagnóstico dos parasitos, com restriçöes à observaçäo de eritrócitos e leucócitos