Biological control of dog hookworm with fungus in Brazil

Abstract

Parasitic nematodes Ancylostoma caninum and Ancylostoma braziliense affect dogs and cats and have great medical and veterinary importance for their high prevalence, zoonotic potential, cosmopolitan characteristic and soil contamination by eggs and larvae. In order to evaluate the efficiency of the nematophagous fungus Monacrosporium thaumasium (isolate NF34a) in the biological control of dog hookworm, 12 adult animals, average weight between 7 and 19 kg, were separated into groups and kept in 2 different kennels: control group (without fungus) and a group treated with 0.5 g of fungal mycelium per kilogram of body weight. The animals were treated and feces samples were collected for egg count (eggs per gram of feces-EPG) and coprocultures during six months, twice a week. Every 15 days soil samples were collected from each group and examined for infective larvae (L(3)) in the period between March and September 2008. From April onwards, EPG and coproculture recordings in the treated group were lower than the control group (p<0.05). Linear regression coefficients for the control group were -30.79 and -160.79 for coproculture and EPG means, respectively. The linear regression coefficients for the treated group were -5.64 and -67.64 for EPG and coproculture means, respectively. Larvae were detected in the soil throughout the experimental period. From June to the end of the experiment (September), means of L(3) recovered from the kennel soil of the control group were higher than the means of the kennel soil of the treated group (p>0.05). The regression coefficient was higher for the treated group (-5.36) than the control group (-1.14), confirming the action of M. thaumasium against larvae in the soil. M. thaumasium can be therefore considered as an alternative environmental control of Ancylostoma spp. in dogs.