[Experimental investigation of canine echinococcosis from swine hydatic cyst in Mexico].

OBJECTIVE To evaluate the infection and obtain the adult state of the cestode, echinococcosis was reproduced in dogs using the hydatic cyst of swine. METHODS Two groups were formed, one of five and the other of three dogs, each animal in the experimental group was given two grams of germinative membrane of fertile hydatic cyst by oral route. The second was the control group. Both groups were evaluated clinically, serologically and parasitologically. One animal was killed on the 35th day after infection and each five successive days until the 55th day. In the second group all the animals were killed on the 55th day. Eggs of the cestode were observed in feces from the 51st post-infection day. The morphological evaluation was made through microscopic observation of the mucous intestine scraping. RESULTS Fifty cestodes were analyzed, ten from each of the infected dogs, 49 (98%) presented three proglottids and 1 (2%) had four; 18 (36%) of the cestodes presented a gravid proglottid. The length of the strobila varied from 1.6 to 2.6 mm. The average of the long and short hooks was 31 and 34, respectively. The length of the long hooks varied from 0.081 to 0.09 mm, the short hooks from 0.034 to 0. 041 mm. The quantity of plasmatic proteins and the number of leukocytes were significantly greater in the control group (P < 0. 05); the quantity of alpha-globulins was larger in the infected group (P < 0.05). CONCLUSIONS The results confirmed the dog-pig cycle, a subclinical infection in the definitive hosts, that makes the diagnosis and control in species closely related to the human being difficult.