sudden aggresion

Question
I have a 2yr old Maltese w/ a little shi tzu.  He has suddenly become aggresive, even biting.  Each time I can find an excuse for him, we were trying to take something from him, or he was backed into a corner.  But the fact of the matter is, I have three children & cannot have a dog that bites.  Can you think of any possible causes?  

I have recently changed his food, from Nutro - to a generic.  The only reason I started to Nutro was to keep him from eating his poop.  He always eats his poop, no matter what we feed him. The kids are also in school all day now, so there is a big change from his day routine to his evening & weekend routine. Another change has been the weather, we live in Michigan & it's now cold & rainy so he's not outside playing as much.  I have an appointment w/ our vet tomorrow but would appreciate any advice.
Thank you,
Kris

Answer
Any time behavior changes suddenly, one should first look for physical reasons. Have your vet go over him with a fine-tooth comb tomorrow, looking for possible pain issues. Be sure to have him check those teeth, too.

Is he neutered or intact? Intact dogs have a tendency to be more aggressive than those that are neutered, but a lot depends on the dominance level of that particular dog. This behavior, though, tends to starts more during the onset of adolescence, around 8-10 months of age (think teenager here), rather than as late as two years.

Generic dog food isn't even good enough to feed goats. Whether or not the change in dog food could have caused this type of behavior change, I cannot say, but if his body is lacking in nutrients, certain changes will indeed happen to a dog, usually in coat and condition, but I do know that some foods have caused excessive chewing and hyper behavior in some dogs. Aggressiveness? Worth a try to put him back on a quality food again, I would think. I would recommend Eagle Pet Products, Solid Gold, or Wellness.

As to the stool eating, there are products that can be put on a dog's food that make the stools very unattractive to them so that they won't eat them. However, the simple solution is to just pick those stools up as soon as the dog eliminates and then he won't have a chance to chow down on them.

If your veterinarian can find nothing wrong with the dog, then you must come to a decision, primarily because of the children in the family. You can either bring in an animal behaviorist and try to modify his behavior through training, or you should have the dog put down. Please don't put your dog in a position to bite someone else (which could result in a lawsuit) if you place him and he bites again. Some dogs just have bad temperaments due to poor breeding and nothing will change that.

Please let me know if your veterinarian finds anything.

Karen