Bad Breath
Dogs aren't known for having wonderfully minty breath, but if you notice a marked change with even a little halitosis, it might be time to take a trip to the veterinarian. There could be something wrong with your dog's oral health. A change in the smell of your dog's breath may also be a cause for concern with respect to his gastrointestinal tract, liver, or kidneys. If your dog's breath smells of urine, for instance, he could have a kidney problem. Sweet-smelling breath is a sign to vets that your dog may have diabetes (especially if he's drinking more water and urinating more often).
Biting
Dogs bite out of anxiety, fear, or aggression. Can you identify which is motivating your pet to do so? Is his mood influencing his actions? If you're having trouble teaching your dog not to bite, consider working with a professional trainer, or better yet, a veterinary behaviorist.
Eating poop
Eating poop can also be an instinctive solution to a nutritional deficiency. Contact your veterinarian especially if your dog is losing weight as well.
Head Pressing
If you notice your dog pressing his head against the wall or another firm object, there's a need for your immediate attention. Head pressing is a common sign of numerous serious problems, such as toxic poisoning or brain disease. Make an appointment with your dog's vet right away.
Sitting on Your Feet or Between Your Legs
This is often mistaken for possessive behavior, but is most often a sign of anxiety or nervousness. "Dominance" is rarely the problem; your dog is probably trying to feel safer by staying close.
