Yes, goldfish can develop worms as a result of overeating. Overfeeding is one of the most common causes of worm infestations in goldfish. When a goldfish eats too much, its digestive system cannot process the food properly, which can create conditions that allow parasites such as worms to thrive.
Worms can cause several health problems, including weight loss, poor growth, difficulty swimming, bloating, lethargy, and loss of appetite. In severe cases, a worm infestation can be fatal.
Treatment typically involves anti-parasitic medication available at pet stores. Prevention focuses on feeding a varied, healthy diet and offering small amounts several times a day rather than one large meal. Flakes, pellets, freeze-dried foods, and occasional live foods such as brine shrimp or bloodworms can provide balanced nutrition.
If you suspect your goldfish has worms, consult a veterinarian for proper diagnosis and treatment.