▁about ▁ 1 3 . ▁In ▁France , ▁the ▁bre ed ▁has ▁a ▁median ▁lif es pan ▁of ▁ 8 . 7 5 ▁years . ▁ ▁Ser ious ▁dise ases ▁can ▁affect ▁the ▁Leon berger — certain ▁types ▁of ▁can cers ▁are ▁very ▁common ▁in ▁the ▁bre ed . ▁G astr ic ▁dil at ation ▁vol v ulus , ▁commonly ▁called ▁b loat , ▁is ▁another ▁serious ▁condition ▁that ▁affect s ▁many ▁of ▁the ▁large - ▁and ▁giant - bre ed ▁dogs , ▁particularly ▁those ▁with ▁deep ▁ch ests . ▁It ▁causes ▁the ▁st om ach ▁to ▁tw ist ▁and ▁can ▁be ▁fatal ▁quite ▁quickly . ▁Ad ult ▁Leon berg ers ▁should ▁always ▁be ▁fed ▁twice ▁a ▁day ▁rather ▁than ▁one ▁large ▁me al ▁to ▁reduce ▁the ▁lik elihood ▁of ▁b loat . ▁Leon berg ers ▁are ▁not ▁alone ▁in ▁inher iting ▁serious ▁dise ases , ▁and ▁according ▁to ▁the ▁University ▁of ▁Sydney ' s ▁L ID A ▁task force , ▁Leon berg ers ▁have ▁relatively ▁few ▁health ▁issues ▁compared ▁to ▁other ▁dog ▁bre eds . ▁ ▁In ▁a ▁ 2 0 0 4 ▁UK ▁Kenn el ▁Club ▁survey , ▁the ▁most ▁common ▁causes ▁of ▁death ▁were ▁cancer ▁( 4 5 % ), ▁card iac ▁disease ▁( 1 1 % ), ▁and ▁" unknown " ▁( 8 . 5 %). ▁In ▁a ▁ 2 0 0 0 ▁USA / Can ada ▁Leon berger ▁Club ▁of ▁America ▁survey , ▁the ▁most ▁common ▁causes ▁of ▁death ▁were ▁cancer ▁( 3 7 % ), ▁old ▁age