Telazia (Thelazia californiensis) are parasites that cause a disease known as telaziosis in cats, dogs, deer, sheep and other mammals. It is quite rare, but its example shows that parasitic worms can live almost everywhere.
The causative agents of this disease choose the lacrimal ducts as their habitat. For animals, this disease is not serious, but, as you can imagine, it is very unpleasant. In rare cases, a person can also become infected.
How do telesias reproduce? Adult females of the parasite lay eggs in the lacrimal duct, from which larvae then appear. Then they enter the body of flies, where they develop within 30 days. When a fly lands near the animal’s eye, the larva crawls out and gets into the eye of its new owner. After 3-6 weeks, she turns into an adult, and the cycle repeats.
Symptoms of infection with telyaziosis. In general, the symptoms are weak. Due to eye irritation, animals may have increased lacrimation, sensitivity to light, conjunctivitis. A secondary bacterial infection may develop. 28-38% of horses in England and the USA are infected with this parasite.
Adult parasites can be found in the conjunctival sac or tear ducts. They are thin worms 1-2 cm long. Eggs and larvae can be detected under a microscope by examining tears and discharge from the eye.
Treatment. You can get rid of adult worms by applying a local anesthetic to the eye. A good result is given by the introduction of ivermectin subcutaneously.
Prevention of telyaziosis. The best way to prevent the spread of this disease is to control the growth of the population of flies that carry the parasite.