Cows dont "flash" red when hit by the player

i had not played Minecraft win 10 in a few weeks but when the new update came out i was like oh i want to see the new skins so i got on and i have played this week all in creative mode and then i decided to make a new survival world so i did and i was surviving ( XP ) in survival mode and then i went to kill a cow and i hit it and it took damage and made noise but did not flash red to show it got hurt, so i tried it again and killed the cow and i killed another just to be sure that it wasn't flashing and it wasn't and i also tested it on a pig and a chicken and they flash, so then i decided to look it up on here did not find anything, so i decided to report it.

steps to reproduce:
1. get on minecraft
2. make a survival world
3. hit a cow and it wont flash.

Thanks!
_{also if i this has already been reported and i did not see then sorry XP}