When it comes to avian patients, many general principles of radiology still apply, just as they would for a dog or a cat.
For example, proper technique and a systemic method for looking at the entire image are important.
However, birds also present unique challenges. For example, their small size means that fine details must be visible on radiographic images. And a bird’s rapid breathing rate can create motion artifact and blurriness, which can compromise radiographic details.
Here are a few strategies and tips for radiographing an avian patient…
Restraint of Birds for Radiographs
Appropriate positioning and stillness of the patient are both crucial for obtaining x-ray images with enough detail to be diagnostic. Because of this, sedation or anesthesia are usually necessary, with appropriate patient monitoring.
Of course, the decision to administer anesthesia depends on the stability of the patient and whether they can handle anesthesia. But even with ill birds, light sedation may still be beneficial to reduce stress, discomfort, or injuries that could be caused by physical restraint.
When administering sedation or anesthesia, be sure to check the best medications and doses for birds, as these may vary from those used for dogs and cats.
Radiographic Technique for Avian Patients
It’s ideal to use the shortest possible exposure time. This helps minimize motion blur due to a bird’s fast respiration rate.
For small patients, tabletop technique is used. A grid is not needed, thanks to a bird’s air sacs which don’t cause significant x-ray beam attenuation or scatter radiation. However, a grid may be considered when radiographing an area wider than 10 cm.
Also, appropriate collimation should be used.
Positioning Avian Patients for Radiographs
Whether a patient is canine, feline, or avian, orthogonal x-ray images are more useful and accurate than single-view x-ray studies. So, whenever possible, try to obtain both a lateral and VD view.
A common view for studies is a “whole bird” radiograph for small or medium-sized birds, which means a head-to-tail view including the coelom, pectoral limbs, and pelvic limbs. However, it’s beneficial to focus on areas of interest, too—whether that’s examining organs in the coelom, evaluating a fractured limb, etc.
To visualize the coelom, it’s best to pull the wings and legs away from the body. That way, there’s nothing overlying the coelomic cavity that could complicate interpretation or cover up important details.
When positioning, it’s best to be gentle, especially with small birds that can be fragile. Pulling the wings too much can cause pain or injury, or lead to over-rotation and improper patient alignment. Tape may be used, but it should have minimal adhesive in order to avoid pulling feathers. Other positioning aids made from clear plastic can also be very useful.
For patients in poor condition, it may make sense to first do a “screening” x-ray via a horizontal beam. For this shot, the bird could be standing on a perch on the x-ray table. Sometimes, this gives enough information to rule out certain conditions (such as egg binding or heavy metal ingestion) and develop a preliminary treatment plan. Then, if needed, more detailed imaging could be pursued once the patient is more stable.
A Few Tips for Bird X-Rays
Here are a few more things to keep in mind when it comes to bird radiographs…
If possible, it’s helpful to fast a patient prior to radiographs of the GI tract. This allows better visualization, and it reduces the risk of regurgitation and aspiration pneumonia. However, keep in mind a bird’s fast metabolism. For very small patients, fasting beyond two hours may be detrimental.
Have a good reference guide available to use as a point of comparison for your patient’s images. This will help not only with distinguishing what’s normal and what’s not for an individual bird, but also for anatomic variations between species.
Consider a referral or consult as needed. There’s nothing wrong with referring a patient to an avian and exotics specialist. Or, if you take the radiographs yourself, consider sending the images for a teleradiology consult.
X-rays can be a very important part of the diagnostic plan for birds. With knowledge and some practice, bird radiographs may become faster and easier for the team, leading to prompt diagnosis and treatment of ailments and excellent avian care.
Written by: Dr. Tammy Powell, DVM
