It is very sad that some training methods are not only misguided but they can be dangerous in some cases and spoil our relationship between us and our dogs.
One method that often causes problems is taking food off a dog.
Many people believe that to show the dog who is the boss they should be able to take food from the dog whenever they want to. To implement that they remove the dogs food bowl when the dog is eating.
Lots of dogs are very forgiving and just put up with our rudeness.
Some dogs begin to learn that they are not safe when they are eating their food and start to become defensive and aggressive when anyone comes near them.
The owner misreads this as the dog becoming dominant and then punishes the dog. The dog then learns that it was correct, it is not safe when it is eating, bad things happen and it can become even more aggressive.
If you imagine yourself if you are eating something yummy and someone comes and takes it away without saying anything. The first time you may be a little confused but say nothing, the second time you may yell 'HEY' the next time you might be holding onto your dish waiting for them to come.
Its true sometimes you may need to take food away from your dog, but rather than get into a battle it is better to teach him to trust you.
Around the food bowl (If your dog isnt already showing aggression) you could casually toss something really yummy into their bowl. You can teach your dog to 'give' you something in its mouth by swapping it for something even better - and then you can even sometimes give them the original thing back again.
Dogs and wolves do not take food off another dog, even the most alpha wolf will leave a cub that has food in its mouth.
This applies for your household dogs too, if you allow one dog to keep taking food or toys from the other dog then he may learn to guard items from other dogs. Mia was very bad for resource guarding from Ben until she understood the rules of the house, it belongs to whoevers mouth it is in.
No matter how nicely mannered your dog is it is also very important to teach children if they drop something it belongs to the dog. If something needs to be taken away from the dog then it should always be you that does it, not a child
Remember if your dogs behaviour suddenly changes check with your vet that there is nothing wrong and if your dog is showing aggression consult a behaviourist