1Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
2Veterinary Practitioner, Tehran, Iran
Attempts were made to present a practical key for identification of small strongyles, the identification of which seems to be a difficult task to do. 4000 nematodes collected from the large intestine of horses and donkeys were examined. 18 species of small strongyles of horse and 15 of donkey were found. From 6 species of large strongyles found in both animals, we only dealt with 3 of Triodontophorus sp. In horses, 3 species of Coronocyclus (C. coronatus, C. labiatus and C. labratus), 4 species of Cyathostomum (C. alveatum, C. catinatum, C. pateratum and C. tetracanthum), 5 species of Cylicocyclus (C. auriculatus, C. insigne, C. nassatus, C. radiatus and C. elongatus), 1 species of Cylicodontophorus (C. bicoronatus), 4 species of Cylicostephanus (C. calicatus, C. goldi, C. longibursatus and C. minutus), 1 species of Gyalocephalus (G. capitatus), and 3 species of Triodontophorus (T. brevicauda, T. serratus and T. tenuicollis) were found. From the above-mentioned species, C. minutus, C. calicatus and G. capitatus were absent in specimens examined from donkeys.