X-Ray is an indispensable diagnostic tool in dealing with wild bird patients and allows a fast, safe and reliable diagnosis in most instances. Sedation is usually not necessary (except for panoramic x-ray). The vet should be experienced in x-ray birds and small animals in order to get an impeccable picture.
In cases of fractures, luxations and other severe injuries it should be considered if it is reasonable to do the painful radiological examination without anaesthesia. Always give oral analgesics (Meloxicam)! Following a surgical wound- or fracture treatment in general anaesthesia it seems logical to do the x-ray already in anaesthesia. In this case it has to be considered whether the traumatized patient is able to receive anaesthesia or not. Common Swifts with injuries which after a clinical exam cannot ensure their ability to be reintroduced into the wild, will only be x-rayed in anaesthesia or post-mortem if this is necessary for scientific interest.
If the x-ray is still done by the old method with an x-ray cassette and not digitally, the cassette should be put directly on the x-ray table to minimize the distance between object and film. The distance film - focus should be 100 cm. X-ray cassettes by the size of 13x18 cm, for panoramic x-rays 18x24 cm, can be used and if needed be divided into two halves by focalising. Depending on which x-ray machine is in use exposure values between 42 KV/10 mAS and 42 KV/12,6 mAS respectively 45KV/8 mAS and 50KV/12 mAS have been suitable. Formerly x-rays of patients of the Common Swift Clinic were taken by a film-foil-system consisting of a green-sensitive medical x-ray-film by the Agfa-Gevaert Company "Perutz Radiolix G Plus". Intensifying screens were used to minimize the radiation dose and to reduce the exposure values. In the meantime digital x-ray is in use.
Indication
In these cases a radiological exam is a necessary indication for the swift foundling and therefore it has to be done:
- Common Swift with asymmetric position of wings and/or incongruent
movement of the wings
- Common Swift with macroscopic and/or palpation recognizable defects of
the wings or the shoulder girdle (instability, crepitus, swelling,
bruising, wounds)
- Common Swift with lameness, paralysis, stiffening of the wings, which
cannot be classified by a clinical exam.
In these cases a radiological exam of the swift foundling is helpful and should possibly be done:
- Common Swift with flaccid paralysis of the feet
- Full-fledged Common Swift, which is found on the ground
- Young Common Swift with knowledge of a long history of wrong diet
If, after a clinical exam, the experienced vet definitely, obviously and without the necessity of further examination cannot ensure the Common Swift's ability to be reintroduced into the wild than it shouldn't be x-rayed intra vitam to safe it from senseless suffering.
X-ray technology
There are four ways to take pictures in the radiological examination:
1) The dorso-ventral survey picture
This method was developed at the Common Swift Clinic in 1999. It’s a great method to show apparently defects in the shoulder girdle, fixation is not necessary and it doesn’t put any stress on the bird. It’s a useful and proven practise for Common Swifts.
The optical path passes dorsal-ventral.
In order to take a survey picture you need a cassette (size 13x18 cm) marked on the sides and covered by a paper-towel. Now you sit down the bird and fully blind-out the picture. Most of the time the moment, when the bird looks around, surprised what’s going on is sufficiently to take a dorsal-ventral x-ray. The natural posture of the sitting bird is the perfect position. Fractures in the shoulder girdle can be seen clearly, defects of the extremities can sometimes not be diagnosed doubtless because of overlay by the feet.
2) Display of the limbs in the two basic positions
By taking a radiological examination of the wings it is obligatory to take two pictures (right-angled) to give a diagnosis. If it is necessary to x-ray the feet you follow the same procedures. The optical path passes medial-lateral and caudal-cranial through wings, ventral-dorsal and medial-lateral through feet.
You don’t need to sedate the Common Swift in order to take a display of the limbs in the two basic positions. In case of a medial-lateral x-ray of the wing, one hand fixes the bird’s breast and the other hand stretches the injured limb to its maximum. Thereafter the caudal-cranial plane is projected on the second half of the plate. Therefore the bird is held with one hand upside-down its head in the neck and its throat on the plate. The other hand stretches the injured wing and keeps it as close to the plate as possible.
The x-ray of the hind limbs works the same. Besides the injured limbs will not be stretched manual, because the feet of the Common Swift are too short to keep the fingers of the examiner out of the optical path. Normally fractures can be seen clearly even if the limb is not abducted. If stretching is necessary, a rubber band can be tied on the foot for straightening.
3) X-rays ventro-dorsal and latero-lateral
This radiological standard method for pet bird patients is rarely needed for Common Swifts. This method is used to examine the internal organs. The cassette is put perpendicular to the examiner on the table. On the lower half the ventro-dorsal and on the upper half the latero-lateral picture is taken. The later-lateral x-ray is unnecessary in order to judge defects in the shoulder girdle. In this case a ventro-dorsal x-ray with the wings spread to its maximums is needed. If necessary the second half of the cassette can be used to clarify if there is a luxation of the articulatio sternocoracoidea. Therefore the bird has to be put in a special position.
In case of the ventro-dorsal x-ray, the unsedated bird lies in supine position on the lower half of the cassette. The left hand fixes the head the right hand stretches the legs. After this, the bird is put in a left lateral position in the upper half of the cassette to take a latero-lateral picture. The wings are put on top of each other and stretched dorsal. With the edge of the left hand the examiner keeps the wing on the cassette and embraces at the same time the head with its thumb and forefinger. The right hand pulls the overlay legs in a ventro-caudal position.
To take an x-ray in a ventro-dorsal position with maximum spread wings you need help from another person. Again the bird is put in supine position and fixed as described above. The other person, who is standing opposed to the examiner, stretches at the same time both wings to their maximums. A special position can be helpful to diagnose a luxation of the articulatio sternocoracoidea:
For this a second picture on the upper half of the cassette is taken, after the first picture with abducted wings. The area of the shoulder girdle is focussed narrowly. The examiner takes the bird in supine position at its carpal joints and pushes both wings medial and caudal at the same time against the body. This leverage dislocates a luxation of the coracoid and the sternum clearly over the medians, often not seen in normal ventro-dorsal x-ray. Both x-ray techniques take a bit practising, but than you will be able to use them quick and safe with unsedated Common Swifts.
