What causes a dog to attack another?

Question

i have 2 female dogs and they get along excellently. but recently the oldest one is getting very dominant. today i was outside and i was watching next doors turtle crawl around when i heard my puppy yelping. when i went over to check the oldest one had pnned her down and started attacking her. when i finally pried them apart my puppy wouldn't move, is now having trouble walking and her leg is bleeding.

is this a dominance thing and will it stop? does anyone have any solutions. putting down or giving away is not an option!!!!

Answer 1

Yes this is a dominance thing are they spayed? It could help some if they are fixed.  

Answer 2

Yes, it is a dominance thing and it will only get much worse if you keep interfering (prying them apart, yelling, hitting, stopping the fight, etc.).

You need to get the puppy to a vet, obviously.

You also need to reinforce the older dog's position as "Top Dog."  To do this, you must ALWAYS speak to, touch, feed, give treats to, play with, pet, give a toy to, etc. the older dog FIRST.  Even if she seems uninterested in what you give her, it is the gesture that counts so you must give it.  This will reassure her that she is still number One in your heart and it get the message to the puppy that the older dog has seniority and is to be respected.  This will bring an end to the fighting.  Not immediately but SOON.  Don't forget to do your part!