HELP!! I need a back yard dog that will guard my back yard and won't dig its way out or jump the fence?

German Shepherds.
Easy to train, and naturally don't leave property very often, so they won't try to escape.
They make great guard dogs.

Just... yeah... in Texas... make sure it has a lot of food and water... maybe even an air conditioned dog house, because that kind of heat can be rough on any breed of dog.

The person that suggested a pit bull and a chain is dead wrong. Pit bulls are awful guard dogs, they were never bred to guard. And chains not only make dogs aggressive but a dog can't guard a yard if he's chained up. I don't think having an outside dog in Texas would work. It gets far too hot in the summer and cold in the winter. Get spot lights if you want to protect your yard.

If it is going to be a strictly outdoor dog in Texas, it needs to be one that can take the heat. A Siberian Husky would have been a really bad mistake. Actually, when it is 110 in the shade, no dog needs to be kept outside.

Labs are NOT good back yard dogs. This particular breed is particularly social and will do best when close to their human care takers.

In fact ASPCA does not recommend that you leave your dog outside, regardless of breed, particularly during extreme weather conditions. I don't know where in Texas you live, but I know it gets super hot and you can also experience severe thunderstorms. Leaving your dog outside will create an anti-social dog.

Why bother getting a dog if you are going to make it live outside??? Especially in the extreme heat out West...that's just cruel...

What's in your back yard that needs to be "guarded"??? Get an alarm or something...a dog is a companion to live inside and be loved and cared for like part of the family...not stuck outside in the sweltering heat so others will be too scared to enter your yard...

NO dog will guard anything without being professionally trained. Not digging and not jumping are TRAINED behaviors. It is not breed related. Any untrained dog that has been left in a backyard can not expected not to dig or try to escape. Personally I think that there is no dog for you. Texas is hot and not a suitable outside temp for any dog.

Well, he should be able to come in a little bit, like during nights and stuff. Or else he'll hate you for keeping him out in the roasting temperatures.
Get someone with shortshortshortshortshort hair. A shorthaired pointer, doberman, german sheperd with a haircut, pittbull.

I live in Texas too. It is hot and I like short haired dogs because the short hair is cooler for the dog but also it is much easier to wash. I bring all my dogs in at night and during the day when I am home they are in and out and when out they have good access to shelter. When I am away at work they are outside and have good shelter. Dogs need a lot of interaction with people or they will not bond. Dogs that are never brought inside are more likely to wind up being the dog that gets into the news for getting into trouble for biting. They also need training in good doggy manners so that you will be able to stand them. A well trained dog is a likable dog. Dogs cost money to take care of. Dog will fall in love with anyone who throws some food to them over the fence and that person can take everything you have.
I have a daughter that has had vandals damage her house. She put up a video security system so that it would be a deterrent and also would identify anyone brave enough or foolish enough to do vandalize again. It is the kind that you do not have to pay a monthly fee for. She did not get an inside security system but that would be an added protection that would have a monthly fee. That would in the long run be cheaper than a dog and much better protection.

Look into your local shelters for adoption. A puppy might not be your best bet as you will need to watch it all the time. A young to mature dog sounds good for you as it will be able to guard your home too. Not all dogs are the same and if you lack it attention or stimulation they will find ways to entertain themselves (thus the digging). Also don't forget to dog proof your yard before you bring home your new family member.

Pit bulls are good guard dogs, along with
Rotweilers, German Shepards, Boxers, Great Danes..
bigger breeds. but in that type of heat NO dog should be left outside during the day for a long period of time. make sure they have shade, plenty of water, and you should probably buy a chain, to attach to their collar so you know for sure they are not able to jump the fence.