Author: Christal Pollock, DVM, Dipl ABVP-Avian
Date: May 27, 2007
Keywords: Body condition score, body weight, pectoral muscle, keel, fat, thin, emaciation.
Always evaluate body condition in conjunction with body weight. Weigh all birds in grams as part of the physical examination. Body condition scoring (BCS) is a useful tool for assessment of a patient’s general health status. The BCS system described below is based on scores between 1 and 5, with 1 being emaciated and 5 being obese for the “generic” bird (Fig 1). Currently there is no universally agreed upon BCS system for the avian patient due to the high degree of species variability. Individual variability is also seen within a species, and may be based on the level of activity (i.e. wing trimmed versus active flier), “life style” (i.e. free-ranging versus captive), and the season of the year (particularly in migratory species).
Figure 1. Transverse sections of the sternum and pectoral muscle mass in the avian patient displaying body condition score (BCS) where (a) is the keel or carina of the sternum, (b) is pectoral musculature, and (c) is the sternum.
1: Emaciation = little muscle, no fat, concave contour (BCS 1).
2: Good condition = convex contour, little subcutaneous fat (BCS 3)
3: Obese: contour extends beyond keel, subcutaneous fat deposits
To evaluate body condition:
- Palpate the contour of the pectoral muscle mass.
- Note the degree of prominence of the keel bone or carina.
- Look for subcutaneous fat deposits over the sternum, sides, coelom, flanks, thighs, and neck. Wetting feathers with alcohol may improve visualization of yellow subcutaneous fat deposits.
The thin bird (BCS 1 to 2) is bony with little muscle over the sternum (Fig 2). The bird in ideal body condition (BCS 3) has a good overall appearance, with a pectoral muscle contour appropriate for the species. An overweight to obese bird with a BCS of 4 to 5 has variable amounts of subcutaneous fat and coelomic distension (Fig 3). Subcutaneous fat deposits in the inguinal space may create a broad-based stance. Fat deposits underneath the beak may create a “double chin”. Fat deposits along either side of the keel may create a part in feathers over the sternum, although the presence of “cleavage” does not necessarily mean the bird is overweight (Fig. 4).
Figure 2. This emaciated bird (body condition score 1) is bony with almost no muscle overlying the sternum. Photograph provided courtesy of Dr. Isabelle Langlois.
Figure 3. Subcutaneous fat deposits in a cockatiel.
Figure 4. Fat deposits along either side of the keel may create a part in feathers over the sternum. Note: The presence of “cleavage” does not necessarily mean the bird is overweight and palpation is required. Photograph provided by Dr. Gwen Flinchum.
In pediatric patients, body condition cannot be assessed by palpation of the pectoral muscle mass, which is small, soft, and flabby. Instead, evaluate the amount of soft tissue and fat over bony areas like the pelvis and toes.
References
Doneley B, Harrison GJ, Lightfoot TL. Maximimizing information from the physical examination. In: Harrison GJ, Lightfoot TL (eds). Clinical Avian Medicine. Palm Beach, FL: Spix Publishing; 2006: 153-211.
Hillyer EV. Physical examination. In: Altman RB, Clubb SL, Dorrestein GM, Quesenberry K (eds). Avian Medicine and Surgery. WB Saunders, Philadelphia, PA: WB Saunders; 1997:125-141.
Pollock CG. Physical diagnosis in the avian patient. Annu Conf Proc Assoc Avian Vet. 2003. Pp. 227-235.
Welle K. Body condition scoring in birds. Annu Conf Proc Assoc Avian Vet. 1995.
