6. Toxic Food or Plants
There are several foods that are very toxic to birds. Chocolate is digested in a different way by birds, and the metabolite, theobromide, is very toxic to them. Baker's chocolate and dark chocolate are the most toxic, and milk chocolate, although less toxic, is still a forbidden food for birds. Caffeine is also metabolized differently in birds, which also results in toxic compounds. There is some data that indicates that some varieties of avocado are toxic to birds, with perhaps the skin and pit being the most dangerous parts. Although unlikely to kill a bird, to be on the safe side, avocado should not be fed to birds. Onions can cause a fatal hemolytic anemia in dogs and cats, but since birds' red blood cells have a nucleus, this may protect the cells from the severe injury that occurs in other species. However, until this topic is studied, it is best to not feed onions to birds.
Some houseplants can be toxic, even fatal, to birds. Lists of potentially toxic plants have been published often in Bird Talk. Outdoor plants can also kill birds. I had a client with a pet cockatiel that died as a result of oleander toxicosis. Oleander is a beautiful flowering plant often used for landscaping in Florida where I live. Most Floridians can recognize this dangerous plant, however, newcomers to the Sunshine State may not know about it. This client, new to Florida, had placed some oleander branches in her cockatiel's cage, so that he could chew on the leaves and bark. When she next checked on her pet, he was already dead! It is very important that owners be able to identify dangerous plants that may be found in their bird's environment.
7. Hand-Feeding Mistakes
There is no doubt in my mind that many a baby bird has expired as a result of hand-feeding mishaps. Unweaned baby birds should not be sold or given to inexperienced hand-feeders for this reason. It is not necessary for a baby bird to be hand-fed by the family purchasing it in order for it to become "bonded" to them. Budgies are routinely tamed down as pets once they have fledged by the parents, and this can also occur with larger birds fed-out by the parents. Baby birds can also be hand-fed by the aviculturist, and be visited by the new owners to allow the babies to become accustomed to their new families. Weaned birds can be sold to owners, and they will settle in with their new families in no time. So, there is no reason for a baby to be fed by an inexperienced owner.
There are many different things that can go wrong during the hand-rearing process, including feeding formula improperly (mixed incorrectly, stored incorrectly, fed at wrong temperature), delivering the food improperly (dirty utensils, forcing food into the baby resulting in aspiration pneumonia, injuring the mouth or crop with feeding equipment), poor husbandry techniques (keeping the baby at the incorrect temperature, not practicing good hygiene, indiscriminate use of antibiotics), just to mention just a few potential problems.
Most commonly, babies are kept at the incorrect temperature, or the food is fed at too low of a temperature, resulting in a slowed down gastrointestinal tract, which can be fatal, if not corrected in time. If the baby is forced to eat, it may struggle and end up inhaling the baby formula, resulting in aspiration pneumonia. If a large amount of food is inhaled, the baby will die immediately, but if a small amount of food ends up in the respiratory tract, the aspiration pneumonia may result in the baby suffering for days, trying desperately to breathe, before it dies.
Infection is common in hand-feeding babies that are not cared for properly. Bacterial infection, fungal infection and polyoma virus infection are the most common infectious diseases in baby birds, and all can prove fatal.
Hand-feeding is best left up to those with experience.
8. Owner-Caused Diseases
Although it is fun to take baby birds to bird shows, swap meets and club meetings, it is very dangerous for the babies. Infections can spread to baby birds, even through the air, even if the owner is diligent about not allowing any direct contact with the babies. Many diseases can prove fatal to babies, especially polyoma virus. Adult birds are also at risk from exposure to other birds from the same sources, as well as from trips to the pet store, as well. Having parties where owners bring their birds can also spread disease. Unfortunately, a bird can carry a disease, and be able to pass it to others without appearing ill. Proventricular dilatation disease (PDD), chlamydiosis (psittacosis), Psittacine Beak and Feather Disease (PBFD) and pacheco's disease may all be spread by birds that MAY appear healthy in physical appearance. Giardia, a one-celled protozoal organism, can be spread by a bird ingesting food or water contaminated by the droppings of an infested bird. Remember that we don't even have tests for some of the diseases that birds can have! Deliberately exposing birds to other birds, even if they have been vet checked, is dangerous and should be avoided, or kept to an absolute minimum.
Many bird owners make a common mistake when adding a new pet to the family. Regardless of the origin of the bird, and any testing run on the new bird, it should be quarantined for at least one month, preferably two, before it is introduced into the home. There is very sound logic for this. If the bird is harboring an infectious agent, the stress of moving the bird to a new home may precipitate it breaking with signs of clinical illness. Not every person can afford to test a new bird for everything we have diagnostic lab exams for, so quarantine can often protect the family's established pet birds from the risk of disease. And conversely, a pet bird may have a sub-clinical infection that it could pass to the new bird, so quarantine also protects the newly acquired bird.
A client of mine had two pet birds, a cockatiel and a quaker. They bought a cherry-headed conure from a pet store, and noticed after about a month that it wasn't acting well. They had put the new bird in their bird room with their other two birds immediately upon bringing it home. The little conure tested positive for chlamydiosis, and because they did not quarantine the new bird, I ended up treating all three birds with injections (once a week) for almost two months. Follow-up testing showed that all three birds seemed over the infection. Then about four months later, they called me because the quaker wasn't acting well. When I inspected their bird room, there was a new green budgie in there! They told me that they had caught the budgie when it landed on the husband's shoulder outside their home. Instead of quarantining him, they once again put the new bird into the same room as their pets. I tested the budgie, and the tests showed that the budgie was shedding the chlamydial organism, as was the quaker! So, all the birds had to undergo treatment for chlamydiosis once again! Although none of the birds died, they had been quite ill. Testing and quarantining might have prevented this.
Owners must understand that it is dangerous for pet birds to have direct contact with their owner's mouths. We carry bacteria and fungi that can cause serious infection, or even death, in our birds. Birds should never be kissed with an open mouth, nor should birds be allowed any contact with the owner's teeth, tongue, lips or saliva.
9. Heat Exposure
Exotic birds, while from warm, tropical climates, cannot tolerate excessive heat. Children, dogs, cats, other pets and birds should never be left in a car during warmer weather, even with the windows partially lowered. Temperatures inside a car can rapidly reach lethal levels.
Heat can also kill birds in a more insidious way. An owner may place a cage outdoors in the shade in the morning, for fresh air, and as the sun slides across the sky during the day, the bird may end up in the direct sun by the afternoon. With no place to escape the sun, a bird may rapidly develop hyperthermia and die. An overheated bird will begin panting, and with panting, will also begin getting dehydrated. Most birds suffering from hyperthermia will try to get out of the sun, and may try to bathe to cool off, if possible. If the bird's body temperature rises high enough, it will seizure and die. Hyperthermia can also occur if a bird's cage is relocated by a window, with no shade to escape the sun. Hyperthermia can also occur in baby birds, if a brooder is set at too high of a temperature, or if the brooder malfunctions.
Cuddly birds are great, but anything with a bed should be avoided.
Colada knows when I am going to fill the container and flies to my shoulder... she cant wait, she is in that container before the water has finished pouring... so as I walk back to the cage I have a very happy Colada splashing me with water the whole way 
