Section: Veterinary Care In-depth
Diagnosis In-depth
A thorough history is an essential component of the diagnosis. Your veterinarian will probably ask you the following questions:
When did the problem begin? Are/were there other respiratory signs such as sneezing and nasal discharge?
Is the redness unilateral (one eye only)? Or bilateral (both eyes)? Did it start in one eye and progress to both?
Is your bird rubbing his head, shaking his head or yawning excessively? Birds with sinusitis (infection in the sinuses) often display these behaviors.
What about your bird's environment? Did the eye problem first begin when the household heat was turned on? Is the bird kept in a dusty room or with birds that produce a lot of feather dust like cockatiels, cockatoos or African grey parrots? Does anyone smoke? Are aerosolized products used near the bird?
Is your bird on a complete, balanced diet, such as a commercial pelleted diet?
Is your bird allowed to fly free? Is there any possibility of traumatic injury to the eye?
Your veterinarian will recommend specific diagnostic tests depending on how severe the symptoms are or how long the problem has been going on. Chronic or recurrent ocular disease may require extensive diagnostic testing. Any combination of the following may be recommended:
A thorough ocular examination. Specialized lighting magnification is required.
Staining of the cornea with fluorescein stain to look for surface ulcerations
Schirmer tear test to look for adequate production of tears
Testing for intraocular pressure using a tonometer. Infections within the eye will cause a decrease in pressure; glaucoma will cause an increase.
Examination of the third eyelid. The eye is anesthetized using a topical anesthetic agent to allow the eyelid to be lifted up to look for foreign objects.
Sampling of the conjunctiva for bacterial or fungal culture and cytology (looking at cell types for evidence of infection or inflammation).
Sampling the choanal (slit in the roof of the mouth) for bacterial culture and cytology
Sampling of the nostrils or nasal cavity for bacterial culture or cytology. Samples may be taken directly from the nostril after dried material has been removed or by flushing the nostril out with saline (salt) solution or by removing some cells through a needle (fine needle aspirate).
A complete blood count (CBC) may be needed to look for evidence of infectious disease, allergies or inflammation. Certain types of white blood cells will be elevated in number with specific diseases. Many types of infectious diseases, such as Chlamydiosis and Aspergillosis have characteristic patterns of white blood cell increases.
Blood tests (serology) or choanal samples for Chlamydiosis. These tests look for the body's response to the organism causing Chlamydiosis (antibodies) or for the presence of the organism itself (antigen).
Serology for Aspergillosis
Serum protein electrophoresis. Certain protein fractions (gammaglobulins) circulate in the blood with many infectious diseases. Analyzing the types of proteins that are elevated in circulation will aid the veterinarian in the diagnosis of these diseases.
Radiography (X-Rays) to look evidence of sinus infection or destruction of bone. Many different views of the head are needed for a complete evaluation. The bird must be held completely motionless, so general anesthesia is required.
CT scans give much greater detail of the orbit, sinuses and bone. This test may not be available in all areas and referral to an avian specialist is usually required.
Endoscopy. This allows viewing the choana (opening to the nasal cavities through the mouth), ears or air sacs with a rigid endoscope to collect samples for biopsy or culture. By directly viewing these structures, your veterinarian can assess the severity of disease, collect more accurate samples and remove foreign objects. This procedure is usually performed by an avian specialist.
