When looking at bird, you must be aware of the ‘masking phenomenon’. Birds are, for the most part, a prey species (i.e., other animals eat them). A natural survival instinct, developed over millions of years, is to hide signs of illness from potential predators – including people (the ‘masking phenomenon’). So, a sick bird will attempt to look healthy until they are so sick they can no longer hide their illness.
This means that, on first look, the bird may appear healthy even if they’re not. Fortunately for us, most sick birds cannot keep this pretence up for more than a few minutes; leaving the bird undisturbed in their cage while you chat to the seller gives the bird enough time to relax and start looking sick (if they are, in fact, sick).
A proper physical examination is best performed by an avian vet, trained and experienced in this technique. However, you can detect many obvious things just by looking. Things to look out for include:
- Wing droop
- Lameness
- Breathing through an open mouth or with exaggerated body movements (unless the bird has only just been caught; even then breathing should return to normal within a few minutes)
- Poor or rough feathering including feather loss
- Watery eyes or feather loss around the eyes
- Sneezing and/or discharge staining the feathers above the nostrils
- Staining of the feathers around the vent
- Excessively watery or poorly formed droppings, or abnormally coloured droppings (be aware that the first few droppings passed by a nervous or stressed bird will be watery, but should return to normal within 10-15 minutes)
Most of these physical abnormalities can be detected just by looking at the bird in the cage. If you are comfortable catching and examining the bird ‘hands-on’, check the bird’s breast muscles and abdomen (between the end of the keel and the pubic bones. The breast muscles should not be excessively fat or excessively thin. The abdomen should be concave, not distended.
Any abnormalities detected should be noted and a guarantee obtained that the bird can be returned for a refund if a veterinary examination shows the problem is going to be detrimental to the bird’s health or purpose. This veterinary examination should be undertaken, within 3-7 days of purchase. Don’t let the buyer put you off with comments such as ‘he’s just moulting’ or ‘it’s just a cold’.
Has the bird been tested for diseases?
One of the biggest developments in avian medicine in the last 10 years has been the ability to detect viral, bacterial, and chlamydial pathogens through the use of DNA testing. Many breeders are now testing their birds prior to sale; although this sounds good (and it is) it must be realised that the diagnosis of a disease relies on more than simply detecting a pathogen in a drop of blood or a feather. Contamination during sample collection, the submission of incorrect samples for the disease of interest, selection of an inappropriate test for that species, and misinterpretation of the results can lead to a bird being incorrectly diagnosed with disease or incorrectly being pronounced clear of disease. For these reasons, avian vets recommend that this testing be done and interpreted by an avian vet.
Birds should also be tested for parasites (internal and external); again, while some breeders can do this testing, it might be best to have an avian vet do it, as some birds have very different parasites from other (e.g., canker is common in budgies and pigeons, but is not seen in conures) – it is easy to make mistakes without experience and training.
References
1. Doneley B (2018) Avian Medicine and Surgery in Practice: Companion and Aviary Birds, 2nd ed. CRC Press