There are a few different types of worms that can infect a bird’s eye and surrounding structures. The most common ones are eyeworms, gapeworms, and air sac mites. Let’s take a quick look at each of these parasites:
Eyeworms
Eyeworms are nematodes (roundworms) that infect the conjunctiva and nasal passages of birds. The most common species that infects songbirds is Oxyspirura petrowi. These worms can cause inflammation, swelling, and discharge from the eyes. In severe infections, they can damage the cornea and cause blindness.
Gapeworms
Gapeworms are also nematodes that infect the trachea and air sacs of birds. The species Syngamus trachea is most common in gamebirds like pheasants and partridges. Heavy infections block the trachea and prevent breathing, causing the bird to gasp with its mouth open or “gape.” This is where the name comes from.
Air sac mites
Air sac mites are tiny arachnids that live inside a bird’s air sacs and lungs. The most common genus is Cytodites. These mites feed on blood and fluids and cause inflammation. They can spread to the airs sacs around the eyes and brain. Heavy infections cause labored breathing, lethargy, and even death in some birds.
Life Cycle and Transmission
Eyeworms
Adult eyeworms lay eggs inside the conjunctival sacs and nasal passages of infected birds. These eggs are shed along with mucus through the eyes and nose. They are then swallowed by intermediate hosts like flies or beetles.
Inside the intermediate host, the eggs develop into larvae. When a bird eats an infected insect, the larvae burrow into the conjunctiva and finish maturing. The lifecycle from egg to adult usually takes 4-8 weeks to complete.
Birds become infected by ingesting flies or beetles carrying larvae. The infection can spread between birds through contact with eye and nasal discharges.
Gapeworms
Adult gapeworms lay eggs inside the trachea. The eggs are coughed up, swallowed, and passed in the feces. If the feces contaminates soil or water, eggs can be ingested by earthworms or snails.
Inside these intermediate hosts, the eggs hatch into larvae that migrate through the body. When a bird eats an infected earthworm or snail, the larvae burrow through the intestinal wall and travel to the lungs. They mature into adults within 3-4 weeks.
The main route of infection is ingestion of infected earthworms or snails. Transmission between birds can occur from sharing contaminated food and water sources.
Air sac mites
The life cycle of air sac mites is direct, meaning they can be transferred directly between birds without an intermediate host.
Adult mites lay eggs inside the air sacs. These hatch into larvae, which molt into nymphs, then into adults. The entire lifecycle can be completed within 2-3 weeks.
Mites spread through close contact between infected and healthy birds. They can also be transferred indirectly by shared dust bathing sites.
Signs and Symptoms
Eyeworms
– Excessive tearing
– Discharge from the eyes/nose
– Swelling around the eyes
– Crusty lesions on the eyes and nostrils
– Corneal opacity and ulcers in severe cases
Gapeworms
– Gasping for air with the neck stretched out
– Coughing and sneezing
– Shaking of the head
– Loss of appetite and weight
– Death from suffocation in heavy infections
Air sac mites
– Labored, whistling breathing
– Discharge or blood from the nostrils
– Lethargy, weakness, emaciation
– Head-shaking, neck-stretching
– Poor feather quality
– Increased mortality in flocks
Diagnosis
There are several methods used to diagnose worm infections in birds:
– Microscopic examination of eye/nasal discharge, tracheal swabs, or fecal samples to identify eggs or larvae
– Necropsy of dead birds to directly observe worms in the trachea, air sacs, and eyes
– Serological blood tests to detect antibodies against certain worm species
– PCR testing to identify worm DNA in samples
– Endoscopy or other imaging to visualize worms in the respiratory tract
A presumptive diagnosis can be made based on clinical signs, but lab tests are needed to confirm the exact type of worm and rule out other causes. Mixed infections are common so multiple sample types may need to be tested.
Treatment
Several deworming medications are effective against eyeworms, gapeworms, and air sac mites:
– Ivermectin – kills many nematode and arthropod parasites. Given orally, topically, or by injection.
– Moxidectin – similar to ivermectin, also treats gapeworms effectively.
– Fenbendazole – broad-spectrum anthelmintic drug, often used for eyeworms.
– Levamisole – treats roundworms and lungworms. Usually given in drinking water.
– Fluralaner – systemic parasiticide, mainly used for air sac mites.
Treatment is most effective when the entire flock is treated together to prevent reinfection. The environment should also be cleaned to remove intermediate hosts and prevent buildup of larvae/eggs.
In individual pet birds, a vet can prescribe medicated eye/nose drops to kill eyeworms locally. Severe infections may require antibiotics for secondary bacterial infections. Supportive care like fluids and nutritional support are important.
Prevention
Several measures can help prevent worm infections in birds:
– Keep wild birds, rodents, and insects out of feed storage areas and bird enclosures. Use covers, screens, and baits.
– Practice good sanitation of cages, feeders, and waterers. Disinfect regularly.
– Avoid overcrowding and stress that makes birds more susceptible.
– Deworm newly acquired birds before introducing into the flock. Quarantine sick birds.
– Rotate deworming medications and treat the flock periodically as a preventive.
– Limit access to areas where intermediate hosts may be present like soil, ponds, and slugs/snails.
– Maintain optimal nutrition and avoid vitamin/mineral deficiencies.
– Control dampness and poor ventilation that allows mite populations to thrive.
Catching and treating infections early is key to minimizing damage and transmission between birds. Both backyard and commercial flocks benefit from an integrated pest management plan.
Conclusion
Eyeworms, gapeworms, and air sac mites are common parasitic worms that can infect the eyes and respiratory tract of birds. They have indirect lifecycles involving fly, beetle, earthworm, or snail intermediate hosts. Infections cause ocular and respiratory signs, which can be severe and even fatal in heavy infestations. Diagnosis relies on microscopic identification of eggs/larvae and blood/PCR testing. Several broad-spectrum dewormers are effective for treatment and prevention. Control measures focus on sanitation, quarantine, surveillance, and integration of multiple strategies to reduce worm burdens. Addressing these parasites is an important part of maintaining both the health and vision of backyard and commercial flocks.
