I have taken in stray cats that were used to killing birds and mice for food; and yet it took me only a couple of weeks to a month to train the cats to leave my indoor birds alone.
I have had several large dogs (Doberman, German Shepherd, several mixed breeds, as well as one American Eskimo, etc.) and they were perfectly fine with my birds -- after careful introduction and training. I am not a very patient person and training does not come naturally with me. If I can do it, anybody can. All it takes is PERSISTENCE!
This being said -- some breeds are more unpredictable than others! Therefore, good judgment in assessing your pets is of the essence.
The biggest mistake people make is to try to keep birds and cats / dogs apart (in different rooms or relying on a cage to keep the bird safe). Eventually someone is going to forget to close the door properly, the bird gets out of his cage somehow, and the cat or the dog is going to take advantage of that. Eventually this is going to happen ...
The most important step - the cage:
Buy a sturdy and large cage with a lock that cats, dogs or birds can't open. You do not want your cat or dog to throw over your cage. Buying a heavy / strong cage is most important for mixed (bird / cat / dog) households. It is also important to buy a BIGGER cage to allow birds to back up from any paws that might try to reach into the cage.
Cats or dogs can easily topple flimsy cages over, thus giving untrained pets access to your birds or cause injury as the cage falls over. The general rule is that the heavier the cage, the better. Stainless steel (if anybody can ever afford those ;-), wrought iron / powder-coated cages would be best. Get a cage with 1/2 inch spacing; not wider than that. You don't want your cat to be able to put her paws through the bars.
Placing the cage in a corner or an area which allows your pet birds to get away from any potential threat is vital. Providing lots of visual barriers (roosting boxes, branches, toys) behind which a pet bird can "hide" when they get scared will help lessen any stress. I would provide a nesting box - for added security - even for non-breeding birds. Many birds like to sleep in these boxes. It also keeps them warm when it gets chilly.
This all being said -- it is best NOT to allow a dog or a cat to be alone in the room where the bird is when you are not around -- until they are trained that is and you are confident that your pet bird is safe. This comfort level may not be reached until you have seen your pet birds and pet cats / dogs interact with each other under your supervision for many months. I personally gained that level of comfort when my birds did get out accidentally and when we got home my pet birds and dogs / cats were together in one area without any signs of physical stress on the pet bird and excitement on my cats / dogs.
Also, accidents can ALWAYS happen. There is no guarantee that an excited pup won't accidentally step or pounce on a pet bird. However, familiarizing your pet dogs and cats with your pet birds will increase the chances of survival for your pet bird should he or she get out of the cage accidentally one day.
Adult Cats / Dogs:
Cats are naturally curious and want to explore the new bird. I used to train my cats by allowing my birds to walk all over them. Initially I supervise very carefully and CLOSELY every one of my bird's and cat's / dog's move. Young birds are usually not very scared of other pets. With older birds, simply holding him or her on your finger and allowing your cat or dog to smell it (as long as the bird is comfortable -- if not, do it in small steps). Watch your cat very carefully when close to your bird. If your cat starts playing with your bird (reaching for your bird), say in a loud voice: “NO!” …Do not allow your cat or dog to lick your pet bird at any time. This could cause infection.
Whenever the cat is doing anything to put the bird at risk or scare him / her, let your cat know that this is unacceptable (loud NO is sufficient). DO NOT allow your cat to lick your bird. This could cause serious infections. Do allow your cat to approach your bird in a non-threatening manner. Praise your cat and dog when they react the way you want them to.
At first your cat or dog will be very curious about the new family member. Eventually he will most likely ignore him. This all being said, I would only allow supervised interaction between the bird and your cat / dog. I have one handicapped cockatiel who lives on a customized tray. Charlie flies off the tray at least once a day and many times the cat is alone at home when this happens. She has never hurt him. Still, this particular cat is very sweet and mellow.
This same training method also worked with my dogs. However, some dog species are bred for hunting and I don't know if one can "turn off" this instinct. I had German Shepherds, and various mixed breeds live happily side-by-side with my birds. I followed the same procedure. Caution and supervision is always important.
Kitten / Puppies:
Kittens and puppies are usually the easiest to train. They are naturally non-aggressive. Please refer to the below series of photos that show one kitten and budgie interacting.
However, an active kitten or dog could playfully pounce on a bird and depending on the size of the bird, this can result in injury or even death. Also the saliva and the scratches (attained during play) of cats specifically is toxic to birds. So it is important to closely supervise their interactions. It is important that if a bird has been scratched by a cat, to alert the vet to this.
Cats and dogs that were raised with birds are unlikely to show aggression towards birds at a later stage - unless provoked. For example, hormonal / brooding hens may be protective of certain areas that she has chosen as her "nesting site." This can happen even if there is no male and is more likely to occur in some bird species than in others. Hormonal male parrots in the breeding season may also attack dogs and cats - which can also result in counter-aggression. So a pet owner will have to use common sense and be watchful when their pets are interacting - especially at those times when you are dealing with hormonal or aggressive birds.
Birds also have to learn that aggressive behavior is not acceptable - be it with their owners or other pets in the household. Many birds have a strong urge to chew. When you see a bird chew on something they shouldn't -- such as the cat's ears or the owner's finger -- a firm "no" and gently redirecting their attention to a chew toy would be a good way to handle this situation.
To Train or Not to Train:
Some pet owners prefer to keep their dogs / cats and birds separate - to play it safe. I personally prefer to train my dogs and cats to get along and act appropriately around birds. My reason for that is that I am not always 100% in control of what is happening in my environment. Someone in the family or friends could accidentally leave the door open allowing the dog into the area where the bird is, and an untrained dog or cat will naturally be attracted to a bird. So the future looks bleak for the bird when this happens.
For the risk of not training dogs and pets to get along with my birds far outweighs the risk of allowing my pets to intermingle - after training them to act appropriately. I found that eventually the dogs and cats lose complete interest in the birds and when someone does leave the door open, a bird lands on a dog or cat -- this is not the end of its life -- as it would be if the dog or cat hadn't been trained.
How a bird owner handles it is up to them - and the decision is likely to depend on their own circumstances, the personality of their pets and home set-up.
Species Research by Sibylle Johnson