(S (S (BASENP (JJ Local) (NN wisdom)) (VP (VP (VBZ cautions) (PP (IN against) (S (VP (VP (VP (VBG allowing) (BASENP (NNS dogs))) (PP (IN in) (BASENP (DT the) (NN water)))) (PP (IN at) (BASENP (NN swimming) (NNS beaches))))))) (COMMA ,) (PP (IN because) (PP (IN of) (NP (BASENP (DT a) (NN fear)) (SBAR (IN that) (S (BASENP (PRP they)) (VP (VP (VBP attract) (BASENP (NNS sharks))) (COMMA ,) (PP (ADVP (RB perhaps)) (PP (IN because) (PP (IN of) (NP (BASENP (NN residue)) (VP (VBN accumulated) (PP (IN from) (NP (BASENP (NNS fleas)) (SBAR (WHNP (WDT which)) (S (VP (VBP live) (PP (IN on) (NP (BASENP (DT the) (NN dog) (POS 's)) (NN blood))))))))))))))))))))) (PERIOD .))