EXPERIMENTAL PATHOLOGIC STUDIES ON SOME TISSUE CYST FORMING PROTOZOA

Abstract

In the present work, fecal analysis was done on about 200 fecal samples collected I from dogs near slaughterhouses and farms of large animals at Alexandria and Behera I provinces. The results were negative for detection ofNeospora or other coccidian oocysts. .\

On the second part of this work examination was done on field cases of dogs (10 stray dogs of some neurologic signs of mainly impairment movements) and rats (about 50 farm rats) from the same localities. I The gross as well as microscopic examination for various organs was done after the I postmortem examination of these animals. Direct impression smears were prepared from the various tissues to investigate the presence of tissue cysts of Neospora and other coccidian parasites.

The positive cases of the farm rats were used for preparation of the infected material to feed for puppies of the experimental group. The pathologic studies for the dogs revealed affection nearly similar to those recorded for Neosporosis. These affections included I severe non-suppurative meningeoencephalitis, parasitic mycorditis with detection of intact ' parasitic cysts, necrotizing hepatitis, interstitial nephritis, interstitial pneumonia with I certain degrees of fibrosis and emphysema and some degrees of testicular degeneration. I The pathologic findings in farm rats were mainly consisted of brain tissue affections of the The follow up for the pathologic affection in these experimentally infected dogs / revealed the appearance of positive parasitic elements of apparently Neospora after the 6th / and 8" weeks of infection where tissue-cysts (intact or ruptured), were detected in many tissue especially the brain, cardiac muscles, skeletal muscles of the thigh and in the } kidneys. During the first 4 week ofthe experiment tissue cysts could not be detected, while the body organs showed numerous pathologic alterations similar to those previously detected in the field cases of naturally infected dogs. It was noticeable that the observed signs of impairment movement as well as hind limb paresis were closely related to those j muscular affections with severe necrotizing myositis as well as excess of intracellular tissue-cystic fonnations which were detected in these puppies, especially on the last weeks 1 of the experiment.