Red Eye in Birds
Red appearing eyes in pet birds are usually due to inflammation of the conjunctiva (mucous membrane surrounding the orbit), the nictitating membrane (third eyelid) or the eyelids. Some species of birds have a red-pigmented iris and therefore normally have a red eye.
It is common for birds to have reddening of the eyes or surrounding structures alone with no other symptoms. This is especially true of cockatiels. Birds with inflammation of the eyes or surrounding structures, however, may have also have an ocular discharge. And, since the sinuses are intimately associated with the eye, many birds will also have symptoms of upper respiratory tract disease, such as sneezing or nasal discharge.
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 redness to the eye or redness accompanied by signs of respiratory disease may require extensive diagnostic testing. Occasionally, irritants from the environment (dust or chemicals) may cause a temporary reddening of the conjunctiva or lids. If the redness persists for over 24 hours, or if other symptoms are present, veterinary attention is necessary.
What to Watch For
- Swelling around the eye
- Sneezing or nasal discharge
- Excessive sleepiness, ruffled feathers and tucking the head under the wing
- Loss of appetite
- Difficulty breathing
- Leaning forward and stretching the neck out to breathe, open-mouthed breathing, puffing out of the cheeks with each breath or bobbing of the tail with each breath
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 redness to the eye or redness accompanied by signs of respiratory disease may require extensive diagnostic testing.
A complete history is extremely helpful in reaching a diagnosis. Be prepared to tell your veterinarian the following:
- When the problem began
- If the condition has changed
- The type of diet your bird is on
- Any potential exposure to dust or chemical irritants
- Any potential exposure to other birds
- A thorough physical examination
- Sampling of the conjunctiva for culture and cytology (looking at cell types for evidence of infection or inflammation)
- Sampling the choanal (slit in the roof of the mouth) for culture and cytology
- A complete blood count (CBC) and serum biochemistry panel
- Blood tests or choanal samples for Chlamydiosis (Psittacosis)
- Radiography (X-Rays) to look evidence of sinus infection or destruction of bone
- Endoscopy or viewing the choanal, ears or air sacs with a rigid endoscope to collect samples for biopsy or culture
Treatment may include any of the following:
- Removal of environmental irritants, such as dust, cigarette smoke or bird dander
- Humidifying the air in the bird's environment or providing filtration
- Antibiotics or anti-fungal medications
Bird showing severe symptoms, especially difficulty breathing, lethargy or loss of appetite may require hospitalization for 24-hour care.
If your bird has an increased redness to the eyes and has no other symptoms, you can do the following:
- Move your bird to a dust-free environment.
- Keep your bird in a separate room away from birds that create a lot of feather dust (cockatoos, cockatiels, African grey parrots).
- Do not smoke cigars or cigarettes around your pet.
- Filter the air in your bird's environment with a HEPA filter.
- If the bird is a tropical species (e.g., Amazon parrot, macaw) provide adequate humidity.
After seeing the veterinarian, be sure to give all medication as directed, for as long as directed, even after the symptoms appear to be gone.
If improvement is not seen, report this to your veterinarian. If the redness is worsening or the bird develops other symptoms, alert your veterinarian immediately.
Avian eyes and surrounding structures differ from those of mammals in several ways. The sense of sight is extremely well developed in birds; therefore the globe (eyeball) itself is significantly larger than that of equivalent sized mammal. The iris is also much larger, filling the entire area of the open eyelids; the sclera, or white portion of the globe visible outside of the iris, is not normally visible. The iris is highly pigmented. In some species of birds, the iris is pigmented with a red or red-brown color, and in these species, a red eye is normal, as long as it is just the iris that appears red.
Often, a mammal's eye will appear red when blood vessels are engorged and visible in the sclera, what we call "blood-shot" eyes. Since the sclera is not normally visible in birds, this is not a common cause of red eye.
Most birds with red eyes have inflammation of the conjunctiva (mucous membrane surrounding the globe), nictitating membrane (third eyelid) or the eyelids themselves. When the nictitating membrane closes, it moves from the upper half of the medial canthus (area of the eye closest to the beak) toward the lower, outside portion of the eye (lateral canthus). If swelling and redness of the nictitating membrane occurs, the red coloration will appear in the medial canthus.
Redness and swelling of the conjunctiva can appear around the circumference of the eye, although it is usually most noticeable on the lower eyelid margin. In pet birds, the lower eyelid moves up when the eye closes. Swelling and redness of the eyelids are also common. These birds usually appear to be in pain, and may hold the affected eye closed.
The avian skull is full of air pockets or sinuses. These sinuses reduce the overall weight of the skull – a necessary adaptation for flight. The sinuses connect with the nasal passages and extend completely around the eyes. Because of this connection, respiratory infections often extend into the sinusitis and periocular tissues. Birds with sinusitis often have swelling surrounding the eyes, due to inflammation of the sinus wall or because the sinus itself is full of exudate (pus). If large amounts of exudate accumulate, the eye may actually be pushed forward, bulging out from the skull.
Inside of the globe itself is a vascular structure, called the pecten, which supplies nutrients to the retina. The pectin is not visible without specialized magnification, because it is located behind the iris. Severe trauma to the globe or infection within the globe itself (inside the eyeball) may cause bleeding within the globe (intraocular hemorrhage). Intraocular hemorrhage is termed hyphema and appears as a solid red eyeball, with no visible pupil.
Inflammation of the conjunctiva may occur due to environmental irritants, such as dust, aerosol sprays or smoke. Birds are extremely sensitive to cigarette smoke, and smoking around birds should be avoided at all times. If possible, eliminate the amount of dust the bird is exposed to. If ocular redness persists for over 24 hours, or if other symptoms are present, veterinary attention is necessary.
Causes of Red Eye
The severity of red discoloration and which portion of the eye affected will vary with the cause. Hyphema is caused by trauma or infection within the eye. Environmental irritants or infectious agents may cause conjunctivitis or eyelid swelling. Conjunctivitis with eyelid swelling and bulging of the eye is usually secondary to sinus disease or tumors.
Possible causes of red eyes include:
- Bacterial infections. Bacteria can infect any portion of the eye and is a common cause of sinusitis. Common types of bacteria causing eye disease include: E. coli, pseudomonas, pasteurella, staphylococcus, streptococcus and mycoplasma.
- Chlamydiosis. This is also known as Psittacosis or parrot fever.
- Fungal infections. Aspergillosis, a fungus normally found in the environment, can cause severe sinus and ocular infections. A build up of exudate from Aspergillosis can cause bulging of the eye. Less common fungal infections include cryptococcus and candida.
- Viral infections. These include poxvirus, paramyxovirus and herpesvirus.
- Hypovitaminosis A. This is a low vitamin A concentration in the diet.
- Irritation due to aerosolized dust and debris, smoke or aerosol sprays.
- Neoplasia. Cancer can occur in the conjunctiva, nictitating membrane, within the globe itself or behind the eye.
- Foreign bodies. Objects lodged under the nictitating membrane can cause red eyes.
- Trauma. Bite wounds from mammalian pets or other birds and flying into objects, such as windows or mirrors are common causes of ocular trauma.
- Allergies. Hypersensitivity reactions to dusts, molds or pollens may cause reddening of the conjunctiva.
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.
There are many causes of red appearing eyes and the cause must be identified for proper treatment. Diseases that can cause severe destruction of the eye and/or sinuses, such as Aspergillosis, many bacterial infections or neoplasia (cancer) will require hospitalization and extensive, long term treatment. On the other hand, birds with eye disease and no other symptoms can be treated on an outpatient basis.
Until diagnosis has been completed, treatment of symptoms might be needed, especially if the problem is severe. The following treatments may be applicable to some, but not all birds with red eyes. These treatments may reduce severity of symptoms or provide relief for your pet:
- Removing any lodged foreign object by flushing the eye or using forceps will provide relief.
- Antibiotics or antifungal therapy is often given both systemically (by mouth or injection) and topically (by instilling antibiotics directly into the eye. Often, this therapy must be continued for weeks or, in the case of Aspergillosis, months. Many of the medications can only be administered by injection.
- Cleaning dried exudate or secretions from the nasal cavities and/or sinuses can be accomplished by flushing the sinuses with a saline solution. If the material is dried, it may be cleaned out with forceps under magnification. This process sometimes requires general anesthesia.
- Surgical removal of tumors under general anesthesia. Occasionally, an entire tumor can be removed completely, resulting in a cure. This is only likely to occur with small, benign tumors. The eye may have to be removed entirely (enucleated). Most types of cancer that occur in the eyes of birds, however, are malignant and invasive. These tumors are extremely destructive and cannot be entirely removed. Partial removal (debulking) may offer temporary comfort and provide tissue from which a diagnosis may be obtained (biopsy).
- Diseases that cause severe destruction of the orbit and sinuses, such as neoplasia (cancer) or Aspergillosis (fungal infection), may prove to be fatal despite any treatment attempts.
- Birds that are dehydrated may require fluid therapy, administered by injection under the skin (subcutaneous) or intravenously.
For mild conjunctival irritation and to prevent future problems, the environment may be modified by:
- Removing environmental irritants, such as dust, cigarette smoke or bird dander
- Humidifying the air in the bird's environment
- Providing filtration of the air in the bird's immediate environment (HEPA filter)
- Providing a high-quality diet, rich in vitamins