Call your vet right away and schedule an appointment for a complete medical examination. Talk with your vet about testing your dogs hormonal balance, neurophysiologic functions and allergies. The test results may reveal the underlying cause. This has been especially helpful in dogs that have mood swings.
When growling or biting has erupted as a consequence of scolding or punishment for behavior such as chewing, jumping, general unruliness, or overprotection of food, these problems must be dealt with swiftly and firmly to correct the aggression it is initiating.
As the dogs owner, you must understand that your dog growls or bites at you as a result of defensive feelings. Even the dog that growls when ordered off the couch is reacting defensively, as it feels its dominance status has been threatened.
If scolding and punishment provoke aggression, your dog is reacting to a perceived threat to its physical safety. In either of these situations, your own threatening behavior may be producing negative results.
If the results of a medical examination show no signs of a medical condition that would be causing this behavior, you will have to examine your own behavior closely to determine what you are doing to make your dog feel threatened.
If you can't hire the services of a professional, I highly recommend you pick up a copy of Secrets Of A Professional Dog Trainer by Adam Katz for indepth instructions on dog behavior training. This ebook is available on my blog. http://dog-behavior-training.blogspot.com/
