Is my dog aggressive? What are the warning signs to look for?

I hate to hear this is happening. Canine aggression is a complex behavior as it can stem from dominance, possessiveness, fear, anxiety, resource guarding or a combination. Most people are not familiar with reading canine body language and training. Because of this, I recommend to work with a professional trainer. Researching on your own will also be helpful. Familiarizing yourself with canine body language and dog training can help you to recognize what your pet is trying to say. You can find many books written on the topic and there is a trainer named Victoria Stilwell who I think is particularly helpful. Best of luck.

This can be a sign of food aggression or you may have simply startled him and that is his natural response to protect himself. make sure he knows you are there next time If it continues then you need to seek training and stay on top of that to make sure he understands that is unacceptable behavior

It's possible that he reacted aggressively because you were around and he felt more threatened or protective - especially if he was on a leash. Some dogs do have certain dogs or breeds that they find more threatening so it's also possible that he was reacting to this one dog. I would watch him closely since this could also be the first sign of dog aggression. If possible I would recommend avoiding this particular dog in the future.

Some dogs do not like to be touched when they are eating, and I would refrain from petting him while he's eating. It can be a sign of food aggression, and it's best to leave him alone when he's eating.

It sounds like Muggs is bring quite seriously aggressive. Firstly you should have him checked by your vet for any medical reason that could explain his behaviour. Following that you need to go back to basics with his training and give him the confidence not be nervous. In a difficult situation like this I would highly recommend employing the service of an animal behaviourist. Your vet may be able to help by prescribing medications but it usually comes down to behaviour and training.

Yes, dogs can become quite food aggressive at times. If this is a new behavior, have Nala examined by your veterinarian. Frequently, illness or injury can lead to sudden behavioral changes. To prevent future episodes, make her "work" for everything. This can be as simple as a sit before eating, playing or going outside. Do not allow her on furniture or bedding. Provide her own bed on the floor. Do not allow her to initiate play or contact. It must be on your terms and when you want to give attention. Do not leave toys out for her 24/7. Give her one or two for a bit of time, then take them away when playtime is over. All these actions will reinforce her position in the home as subordinate to you.

Any dog that all of a sudden acts aggressive it is usually due to some type of pain in the body. If he is not eating he may have an intestinal obstruction and that is painful. I suggest you get him to a vet for an exam.