There were investigated the glycogen deposits in Toxocara canis tissues in norm and after the treatment with pyrantel pamoate and albendazole in vivo. Two trials with 8 and 5 puppies in each were applied. Trial 1 was given a recommended single therapeutic 14.4 mg/kg dose of pyrantel pamoate. Trial 2 was given a recommended single therapeutic 30 mg/kg dose of albendazole. Drugs were fed to each puppy individually. Two infected puppies were left untreated as controls. T. canis, eliminated from the host intestine, were quickly collected and prepared for histochemical examination (PAS reaction). Histochemical examination was carried out on the helminths eliminated from the host intestine 8, 12, 24 and 36 hours after the treatment with pyrantel pamoate and 19-21, 32-33, 37-38, 46, and 54 hours after the treatment with albendazole. A distinct positive PAS reaction of hypodermis, muscle cells, epithelial cells of intestine, epithelial cells of sexual tubes and of eggs was observed in the control T. canis. Both used anthelmintics at first decreased glycogen deposits in the epithelial cells of intestine of T. canis. Pyrantel pamoate acts on glycogen deposits in the muscle cells of T. canis stronger than albendazole. There has been observed a negative PAS reaction of these cells of T. canis 36 hours after the treatment with pyrantel pamoate. Then after the treatment with albendazole, a negative PAS reaction in the muscle cells was established only in the helminths that were eliminated from the host intestine in 54 hours. Lateral cords and hypodermis of T. canis show a weak PAS reaction 21 hour after their treatment with albendazole, whereas after the treatment with pyrantel pamoate and even 24 hours afterwards, these tissues show a distinct positive PAS reaction. It is interesting to note that sexual tubes and sexual products show a positive PAS reaction up to the end of the experiment with pyrantel pamoate (36th hour). Also, after the treatment with albendazole, sexual tubes show a distinct positive PAS reaction on the 37-38 hour, while a negative PAS reaction of these organs was established only on the 46th hour of the experiment with albendazole. It might be concluded that pyrantel pamoate and albendazole affect the amount of reserve carbohydrate glycogen in the tissues of T. canis and cause its decrease and disappearance.
