▁attacks ▁on ▁sheep ▁her ds . ▁This ▁also ▁is ▁said ▁to ▁d eter ▁future ▁attacks ▁by ▁the ▁tested ▁co y otes . ▁Coll ars ▁have ▁also ▁been ▁used ▁on ▁wol ves ▁for ▁similar ▁reasons . ▁This ▁document ▁is ▁the ▁assess ment ▁of ▁the ▁shock ▁col lar ▁on ▁wol ves ’ ▁long - term ▁behavior . ▁The ▁article ▁tal ks ▁about ▁trying ▁to ▁alter ▁wol ves ’ ▁behavior ▁over ▁an ▁extended ▁period ▁of ▁time ▁using ▁the ▁col lar . ▁The ▁cons ensus ▁was ▁while ▁it ▁did ▁have ▁an ▁effect ▁while ▁in ▁use ▁and ▁tempor ally ▁after ▁it ▁was ▁removed , ▁the ▁study ▁concluded ▁that ▁longer ▁expos ure ▁would ▁be ▁needed ▁to ▁have ▁any ▁substantial ▁evidence ▁( H aw ley , ▁ 2 0 0 8 ). ▁As ▁far ▁as ▁non - le th al ▁alternatives ▁these ▁two ▁sources ▁both ▁concluded ▁that ▁shock ▁coll ars ▁are ▁the ▁most ▁effective ▁d eter rence ▁to ▁pred ators . ▁Both ▁groups ▁continued ▁their ▁research ▁and ▁the ▁Wild life ▁Society ▁has ▁developed ▁a ▁new ▁and ▁improved ▁version ▁that ▁elimin ates ▁the ▁risk ▁of ▁neck ▁injury ▁when ▁used ▁on ▁animals ▁that ▁previous ▁versions ▁caused . ▁They ▁have ▁increased ▁battery ▁life ▁and ▁the ▁dur ability ▁of ▁the ▁unit . ▁They ▁de vised ▁a ▁unit ▁that ▁is ▁worn ▁like ▁a ▁back ▁pack ▁for ▁the ▁animal . ▁Pre vious ▁versions ▁caused ▁excess ive ▁rub bing ▁and ▁sor eness ▁as ▁well ▁as ▁being ▁ir rit ating ▁for ▁the ▁animal ▁to ▁the ▁point ▁were ▁they ▁would ▁try ▁to ▁take ▁the ▁har ness ▁off . ▁