2 Answers

You want to use, "please kill" as a command to your attack dog? Simpler is better when training dogs in verbal commands. Just say kill. Can you speak German? You have to be able to pronounce the words. Below is a list of German words representing kill. 

töten
kill, kill off, deaden

umbringen
kill, murder, slay, make away with

vernichten
destroy, annihilate, crush, kill, exterminate, obliterate

erschlagen
kill, slay, strike dead

killen
kill, murder, hit, do in, bump off

totschlagen
kill, swat, beat to death

zerstören
destroy, ruin, demolish, wreck, spoil, raze

schlachten
slaughter, butcher

morden
murder, kill, slay

schlagen
beat, hit, strike, knock, defeat, smite

erlegen
kill, shoot, bag

Here is the list for the word attack

verb
angreifen
attack, engage, assail, charge, tackle, impugn

attackieren
attack, charge, hit out

überfallen
attack, raid, invade, mug, assault, hijack

befallen
attack, affect, infest, overcome, befall, beset

anfallen
accrue, accumulate, attack, assault, assail, savage

stürmen
storm, attack, charge, assault, rage, plunge

angehen
tackle, approach, concern, start, attack, fight

noun
Angriff
attack, assault, aggression, raid, strike, charge

Attacke
attack, onslaught, broadside

Befall
infestation, attack

Überfall
attack, raid, assault, invasion, ambush, mugging

Anschlag
stop, attack, impact, plot, notice, assassination  

And you thought this would be easy.  

Below is a list of words for seize

ergreifen
seize, grasp, grab, grip, take up, embrace

beschlagnahmen
seize, confiscate, impound, requisition, appropriate, monopolize

greifen
grab, reach, grip, grasp, seize, hold

erfassen
capture, record, grasp, cover, understand, seize

fassen

take, grasp, hold, touch, catch, seize

nehmen
take, adopt, use, take on, pick up, take away

packen
pack, grab, seize, pack up, grasp, grip

besetzen
occupy, fill, cast, seize, garrison, squat in

pfänden
seize, impound, distrain upon

erhaschen
catch, grab, seize

kapern
capture, seize, take, grab, collar

festnehmen
arrest, apprehend, seize