Disclaimer: I made this avian body condition score chart based on a similar one I illustrated for my raptor center. While I have been working closely with birds for years and years and just started veterinary med school, I have another 3.5 years to go before I am a full, licensed veterinarian, let alone one who is specialized to see avian patients. And even if I was, it would still be unsafe, inappropriate and illegal for me to give medical advice about your pet over the Internet, so if you have a medical concern about your bird (be it raptor, chicken, parrot, or otherwise), please do the right thing and take it to your veterinarian. He/she has years (at least 7) of education, training, and experience that you will not get from Dr. Google. Diagnoses can not, and should never, be made by asking your tumblr followers for their opinions, googling, etc. Please make the right decisions for your fur/feather/scale child!
An avian patient’s general body condition can be evaluated by palpating, or thoroughly feeling, its breast (pectoral) muscles. This will help subjectively determine the ratio of muscle mass to the sternum or keel (breast) bone that these muscles attach to. If a bit of a depression isn’t felt on either side (i.e. the breast is very rounded), the bird is likely overweight; alternatively, if there is an extreme depression (such that the keel bone feels “sharp”), the bird is underweight. In addition, the bone should be straight, and any deviations (e.g. bends/abnormal shapes, cracks, etc.) suggest improper nutrition during the bird’s early life, or a previous traumatic injury that has healed. Keel bone deviations are found in the majority of commercial laying hens, especially due to collisions and falls that occur in “enriched” cages.
Some veterinarians may use a 9-point scale system during a physical exam instead, but the same ideas still apply. As I said above, I use this 5-point system with the raptors I work with at my facility. To minimize stress, part of the preliminary training we do with each of our raptors when they first arrive, after learning to stand on a glove, is to remain calm and still while its handler palpates its keel. This eliminates the need for stressfully restraining the bird, so that it can participate in its own health check process by allowing its handler to touch it (wild raptors are not social, and do NOT enjoy human contact), and receive a food reward in the process. Most parrot owners will train this behaviour as well for appointments with their veterinarian, and I have actually trained my chickens to stand still while I palpate their keel too! No chasing/catching and towel-wrapping necessary. It’s a pretty fun and very useful behaviour to train - the borbs get free food just for letting you poke their boobs?
Please do not use or re-post without permission.
Avian Medicine: Principles and Applications - by Ritchie, Harrison and Harrison (1994)
https://www.wsava.org/WSAVA/media/Arpita-and-Emma-editorial/Body-Condition-Score-Dog.pdf
https://www.wsava.org/WSAVA/media/PDF_old/Body-condition-score-chart-cats.pdf