Avian Emergency and Critical Care (1 & 2)

Introduction
Birds, particularly the smaller species (e.g. lovebirds, budgerigars, cockatiels) are commonly presented to the (avian) veterinarian as emergency patients. As most birds mask their clinical symptoms until the end-stage of the disease, it is common to have chronically ill, cachectic, debilitated birds presented as an emergency case. Such birds are often too weak to be extensively examined. Examination is therefore often limited to an evaluation of the bird from a distance, which allows the assessment of the bird’s behaviour and posture, ability to ambulate and perch, respiratory status, and plumage condition. In addition, the cage can be examined for the presence of regurgitated food, blood, or other discharge. Faeces, if present, can be evaluated macroscopically (volume, colour, consistency, presence of blood or undigested seeds), and microscopically for the presence of disease agents (e.g. parasites, bacteria, yeasts). A quick physical examination is only performed if the condition of the bird allows it, and should be kept to a minimum to reduce restraint and stress associated with it. A full physical examination or further diagnostic tests should be postponed until the patient is stable. For this purpose, provision of adequate supportive care in the form of fluid therapy, nutritional support, heat and oxygen supplementation, is almost always necessary.

Supportive Therapy
Fluid therapy
Most birds presented as in emergency case will show some degree of dehydration or, in more severe cases, symptoms indicative of shock (e.g., red and dry mucous membranes, slow capillary refill time of the brachial artery, poor skin turgor, decreased heart rate, low blood pressure). In such cases, fluid therapy is essential to restore perfusion and hydration.

The amount of fluid that needs to be given to the patient depends largely on the degree of dehydration that is present. Often, a volume of 100-150 ml/kg/day is administered, which also includes the daily maintenance requirement for fluids (estimated at 50 ml/kg/day or 5% of the bodyweight in most birds).

Fluid can be provided to birds in various ways. The route that is used often depends largely on the condition of the patient.

Providing oral fluids is a very practical way of fluid administration and can be performed by owners themselves. This route is often used for waterfowl and other large species in which administration of intravenous or subcutaneous fluids is difficult.

Subcutaneous administration is used primarily for maintenance fluid therapy. The interscapular area and precrural fold are the most commonly used locations for subcutaneous injections. Particularly the precrural fold has the advantage of allowing large volumes to be given (up to 25 ml/kg) without having the risk of entering an airsac. Although subcutaneous fluid administration might not be ideal for use in birds that are severely dehydrated, it is frequently the only easily accessible route available.  [...]