Why does my 20 lb rat terrier chase, bark at and try to pounce on my 2 lb chihuahua?

It's weird and I don't understand. She growls at the chihuahua and if we pick the chihuahua up to get her away from my rat terrier she barks at the chihuahua. Is it bad?

She probably thinks the chihuahua is a rodent.

TERRIER. High prey drive. Chihuahua = small prey

You probably didn't socialize the two dogs well enough. The rat terrier does not like the other dog being there, she thinks its her territory and another dog isn't allowed in. Google "dog socialization" and see what pops up. Good luck! You'd better correct this behavior before it escalates - the larger dog could injure or KILL the small one.**Picking up the chihuahua makes the rat terrier jealous so she barks more.Good luck!

It sounds like she is just playing. Maybe also establishing dominance. If the chihuahua rolls over on her back, that is a good sign. She is showing submission to the older, bigger dog.Give them some time together, but watch that their play does not become too aggressive. Separate them if you think they will actually fight. Then try to walk them together on separate leashes and let them get used to being together is a safe environment.

She may be playing (rudely and too boisterously, but playing nonetheless). Many dogs prefer to play roughly, and chasing, pouncing, wrestling, nipping, barking and growling are all normal parts of dog play. Is her body relaxed when she's behaving like this? A good sign that she's playing is that her body is relaxed rather than being tense, that her gaze isn't fixated, her tail isn't stiff, so on and so forth. It's even more likely that it's play if you happen to spot any playful gestures like play bowing or pawing at the air.If she's pretty tensely fixated on the Chihuahua, then perhaps the tiny little Chihuahua is sparking her prey drive. All dogs have prey drives to some degree; prey drive a predatory animal's instinctive urge to chase and/or kill small, fast-moving, prey-like animals. As their name suggests, Rat Terriers were designed to hunt vermin, so they tend to have pretty high prey drives, and I'm sure you can understand how your two-pound Chihuahua resembles a rodent as far as size is concerned. There are even male fancy rats that reach two pounds..It's also possible that she just doesn't really get along with the Chihuahua, although the chasing and pouncing isn't indicative of aggression (and the barking isn't unless it's a deep, threatening bark, and the growling isn't unless her lips are pushed forward in a pucker or drawn back to show her teeth), so that's less likely.

OK you have a dangerous situatio for your chihuahua there. Yes it is bad but you are actually creating the situation. Every time you pick up your chihuahua, you are elevating it in front of the rat terrier and telling the rat terrier that your chihuahua is above it in the pack order of your family. This might be making your RT angry and confused because it thinks that it should be above the Chihuahua in rank. He wants to put your Chi back in it's place below him in pack order, as in, at the bottom of the pack. So you need to start treating your RT as the dominant one which means, feed it first, greet it first, give it attention first, Pick up your RT and hold it above the Chihuahua. Call your RT first when you come home or go to the park or when you want to feed them. Let your RT eat first in front of the Chihuahua. If you stop picking up your Chihuahua, and leave it on the ground, the RT will not get conflicting messages and should relax about it.But right now, you may have to put your Chihuahua in a crate or other safe place (on the ground!) to get your RT used to its presence without harrassing it. Your RT should start to relax more if you give it lots of attention and only give your Chi attention second in line - but DON'T keep picking it up in front of the RT. If you really like to pick up your Chi (and don't forget that isn't a good message to give the Chi either), at least do it where the RT can't see you doing it.Also take your RT out with you and leave the Chi at home a few times. That will tell the RT that it is the dominant one (being chosen to go out with Alpha which is you) and it will feel much better. At the moment you keep favouring the Chi and that is causing the problems.

Because it is a RAT terrier and your dog is about the size of a rat.Terriers have high prey drive,so you need to watch them very closely.The terrier could easily kill the Chihuahua.