Correlations between mean echogenicity and material properties of normal and diseased equine superficial digital flexor tendons: an in vitro segmental approach.

The objective of this study was to test the hypothesis that tendon echogenicity is associated with the material properties of the corresponding tendon site, especially in case of lesions, due to local changes in tendon matrix composition. Four normal and nine spontaneously injured equine superficial digital flexor tendons (SDFT) were isolated then ultrasonographically examined under tension, in a special device placed in a water bath. Ultrasonographic transversal images (7.5MHz linear transducer) of five segments along each tendon were digitized, and analyzed in order to measure the mean cross-sectional area (MCSA) and mean echogenicity (ME) of each segment. The tendons were then tested in traction until rupture in a testing machine. For each segment, stress and strain were determined throughout the test, and the elastic modulus (EM) was evaluated. The tendon lesions were also documented by histology. No correlation was found between ME and the material properties of normal tendon segments. At the rupture sites of the nine diseased tendons, ME was positively correlated with maximal stress and EM, whereas no correlation was demonstrated with maximal strain. Besides, a positive correlation was demonstrated between ME and both MCSA and EM, when the three metacarpal segments of the diseased tendons were considered. Although ME gives only rough information about tendon matrix structure, it does show, under these in vitro conditions, significant correlations with material properties of pathological tendon segments, which may improve the functional significance and therefore the prognostic value of the ultrasonographic examination of tendon lesions.

Prevalence, abundance and site distribution of equine small strongyles in Normandy, France.

Forty-two horses from Normandy (France) were examined post-mortem for small strongyle infections from October to March. In the positive horses, total worm numbers ranged from 234 to 90,247 (mean 11,297). Encysted larvae represented the major part of the total cyathostome burdens with a high percentage (83%) being early third stage larvae. They were mostly recovered from the caecum (48%) and ventral colon (40%) and were less present in the dorsal colon (12%). Adult cyathostomes were mainly located in the ventral colon (64%) and less frequently in the dorsal colon (27%) and caecum (9%). Twenty species of Cyathostominae were identified. The 10 most prevalent species (in sequence of prevalence) were Cyathostomum coronatum, Cylicocyclus nassatus, Cylicocyclus insigne, Cyathostomum catinatum, Cylicostephanus goldi, Poteriostomum imparidentatum, Cyathostomum labiatum, Cylicocyclus ultrajectinus, Cylicostephanus calicatus and Cylicostephanus minutus which comprised 84% of the total adult population. Twelve species showed a site preference in the ventral colon, five in the dorsal colon and only one in the caecum while two species were collected in nearly equal numbers from the ventral and dorsal colon. The number of species per horse ranged from 1 to 12 with a median of 5. Infections with singletons occurred in 12.5% of the positive horses while multiple infections were encountered in 87.5%. A positive correlation was found between the intensity of cyathostome infection and its diversity, measured either by the number of occurring species or Shanon indexes.

Mast cell and eosinophil mucosal responses in the large intestine of horses naturally infected with cyathostomes.

From December 1998 to March 2000, caecum and ascendant colon of 42 horses naturally infected with cyathostomes were collected during routine necropsy or from a local slaughterhouse. Changes in the numbers of mucosal and submucosal mast cells (MMC and SMMC), intraepithelial, mucosal and submucosal eosinophils (IE, ME and SME) in the large intestine were investigated by histochemical techniques in relation to the worm burdens. The effect of age was examined in three subgroups: 6-24-month-old horses (group 1), 2-10-year-old horses (group 2) and horses more than 10 years of age (group 3). No globule leucocytes were detected in any sections. No significant variations with breed or sex were observed in cell counts. The main variations were higher eosinophil counts in groups 2 and 3 and a marked increase of the MMC counts in the oldest horses (group 3). For each cell type, the infiltration was homogeneous and generalised along the large intestine. In the whole horse sample, the IE numbers were the only parameters that correlated with the MMC and SMMC counts. Very few significant relationships were found between mast cells and eosinophils in groups 1 and 3, whereas numerous positive correlations were recorded in group 2. In the whole horse sample, several correlations were found between different cell counts and cyathostome burdens. The numbers of larvae, adult worms, and the total worm burdens were related to some of the tissular eosinophil counts while the percentage of early third stage larvae (EL3) was linked to mast cell densities. These relations between cells and worm populations showed variations with age. In group 1, most of the significant associations were found between eosinophil counts (IE and SME) and the total numbers of larvae and worms; in group 2, they were noticed between the three eosinophil types and the total cyathostome burdens. In group 3, a MMC hyperplasia was observed and correlations were mostly recorded between these MMC and the total numbers of adult worms or the percentage of EL3. Several associations were also detected between eosinophils (mainly ME and/or IE) and different cyathostome burdens. These variations in the relationship between inflammatory cells and cyathostomes seemed to be consistent with the cellular changes observed among the three age groups. These results suggest that eosinophil and mast cell infiltrations quantified in the large intestine wall might be associated with cyathostome infection.

Dois casos de rutura do diafragma na espécie eqüina / Two cases of rupture of the diaphragm in equine specie

A rutura do diafragma é uma afecçäo rara na espécie eqüina. No entanto, parece haver uma predisposiçäo das éguas em fim de gestaçäo. A rutura é causa de cólicas e distúrbios respiratórios. O diagnóstico, raramente feito em animais ainda vivos, depende de um exame clínico muito acurado. A evoluçäo é muitas vezes fatal.