Occasionally, adult worms may go to sites other than the large veins and heart, and cause ectopic infection. If they go to the eye, an individual may show conjunctival discharge, photophobia, or keratitis.
Treatment is by surgical removal of the worm, and adulticide treatment is contraindicated.
If the worms migrate to the CNS, they are usually found in the cerebral arteries or the lateral ventricles. Signs vary, but may include convulsions, blindness, ataxia, excess salivation, prostration, and coma. Treatment is by surgical removal. Systemic arteries may also be involved in heartworm infection. The rear legs are most commonly affected.