Dermatitis in pets: Study of Brazilian savannah plants as potential antibacterial agents

Dermatitis is a general term that describes an inflammation of the skin, which could be caused by many agents. Some common causes of dermatitis in pets are bacterial, fungal, yeast, and parasite infection, as well as allergies or even trauma. Bacteria obtained from several pets as dogs and cats, presenting clinical signs of dermatitis were collected, cultured in appropriate culture media and then tested by in vitro assays (Kirby Bauer method) using ethanol extract from leaves of Anacardium humile, Byrsonima crassifolia, Eugenia dysenterica and Annona crassiflora, which were harvested in Brazilian federal district. Brazilian savannah (cerrado) comprises many species of very rustic and resistant plants. The material was dried at 37 °C, transformed to powder by a grinder and used in maceration with ethanol for for five days, under constant shaking, at room temperature. Afterwards, the extracts were filtered, concentrated using an evaporator at 50 °C and finally, stored at 4 °C. 30 µl of concentrated ethanol extract from all plants mentioned above were used in all tests. After 24h, all extracts were able to inhibit the growth of all bacteria tested (S.aureus, P. aeruginosa, E. coli, S. intermedius, S. coagulase, B. circulans and S. hyicus). A. humile extract presented greater efficiency against S. aureus (halo of 14 mm) while B. crassifolia was more active against B. circulans (halo of 15 mm). E. dysenterica extract was more effective against S. aureus, B. circulans and S. intermedius (halo of 11 mm for all three bacteria). Finally, A. crassiflora extract inhibited more effectively B. circulans (halo of 11 mm). Although many prescription topical creams are effective against dermatitis in pets, damage could occur using these treatments for extended periods. Thus, the fact that plant extracts exhibits antibacterial activity is very interesting, but it is only a preliminary piece of data and should be followed by the identification of the active compounds.