Introduction to salmonella
Salmonella is probably the bacterial species which most people would be able to name in a pub quiz – along with e.coli it is the most well-known bug there is. Sadly, this is not because it is in any way bird or human friendly. It can cause serious illness and even death and can be passed from owner to bird and back the other way and can even be caught from wild birds in the back garden. It can be carried asymptomatically, so it is not just a case of avoiding people and birds who seem to be ill and it can rip through a flock in days, leaving some dying and others virtually unaffected. There are more than 2000 species, an unwieldy number which for convenience are split into subgenera, and the species that affect birds occur in only two of them, but mainly Subgenus 1. Even so, this leaves a lot of different species on our list of bacteria to beware of and not only does each one present differently, some species of bird have their own very special response to a salmonella infection. So, dealing with it is not a simple matter.
Signs a bird has salmonella
As with so many early symptoms, the first signs of a salmonella infection in a bird are the same signs that might be seen in a number of other conditions and therefore time may well be lost in tracking down and treating the infection. Although some birds may well have the infection subclinically, it is likely that in any collection that several birds will be ill together, and this is an extra clue. This does not help much in the case of single companion birds, but it is likely that because they have a close relationship with their owner that the symptoms may be spotted earlier on. Generally, the bird will be lethargic, with a loss of appetite and very likely diarrhoea. If the case is chronic, arthritis may be another symptom, but this does not apply to all bird species; pigeons are particularly susceptible to both salmonella and the arthritis symptom and it is tempting to wonder if that is why all the pigeons in Trafalgar Square look as if they are having trouble with their feet. Other species specific symptoms include the nasal discharge and dermatitis which African Greys suffer from. Lories and lorikeets are particularly prone to salmonella infections and their mortality rate is higher than with most other birds, the infection tending to be the acute form and very aggressive in its symptoms, with profuse yellowish green diarrhoea. Other signs which may follow the initial diarrhoea and lethargy may include abnormal thirst and organ damage.
Treatment of salmonella in birds
Because there are so very many species of salmonella which can cause infection in birds, the first port of call when the vet has reason to suspect salmonella is to find which is the causative organism. While the results are pending (sensitivities usually take one to two days to come back from the lab) the vet will probably start the bird on broad spectrum antibiotics, to be replaced later with one which is more specific. Since the bird will probably be suffering from diarrhoea, which may bring with it the extra worry of dehydration, it is important to treat this also and for this a proprietary medicine can be used, based on kaolin, which firms up the stool without introducing any other medicines which may interfere with the action of the antibiotic. Support of the bird will be necessary, with extra warmth if needed and clean water and tempting food. Not all birds survive a salmonella infection – if a hatchling has been infected in the egg death is a very likely outcome – but with proper nursing it is certainly perfectly possible.
Prevention of salmonella spreading
Salmonella is a bacteria which is present in everyday life and it will only cause infections if its numbers become overwhelming in unclean conditions or if the bird (or indeed human) is young, old or immune suppressed. Although it cannot be eradicated in the environment, it is certainly possible to make sure that its numbers are kept as low as possible by scrupulous cleanliness and also a good dose of commonsense when it comes to handling birds. If a bird is new to your home or to a captive flock, it is essential that it comes from a reputable source. If for some reason you obtain a bird from somewhere you are not sure about, it is a good idea to isolate it until it is clear that it has no underlying infections; this is sound practice anyway, to prevent the spread of other diseases. As the salmonella bacteria are spread in the air, it is important that the new or suspect bird should be housed separately, so that no aerosols created during preening or flight or from faeces or nasal discharge could carry to other birds.
Cleanliness when handling birds
For the same reason, it is important that you should wash your hands thoroughly both before and after handling a bird – don’t forget that you can give salmonella to your bird and they can just as easily return the compliment! It is certainly important that people are not allowed to handle new birds or any bird in your collection without taking this simple precaution. But not only people and birds spread salmonella – rodents and flies have also been proved to be carriers, so it is very important to make sure that no stale food or droppings are allowed to build up in aviaries and cages to attract them.