The walking animation of sniffer does not change their speed when using hi-speed effect

just like MC-260251

Step to reproduce

1. use spawn egg or summon command for sniffer
2. use effect command 

   /effect @e [type=sniffer] speed 999999 10
   

1. Watch to see sniffer to run it happens

Observed Result

The sniffer is too slow in walking animations for changing movement speed

Expected behaviour

walking animations can should be match the movement speed