1. Bacterial Infections: Bacterial infections, such as Columnaris or Mycobacteriosis, can lead to inflammation and swelling of the eyes, causing them to bulge.
2. Fungal Infections: Fungal infections, such as Saprolegnia or Achyla, can also cause inflammation and bulging of the eyes.
3. Parasitic Infections: Parasitic infections, such as those caused by Ichthyophthirius multifiliis ("Ich") or Dactylogyrus ("Gill Flukes"), can affect the eyes and result in bulging.
4. Dropsy (Edema): Dropsy, a condition characterized by fluid buildup in the fish's body, can also cause bulging eyes due to excessive fluid retention in the tissues around the eyes.
5. Genetic Abnormalities: Some betta fish may have genetic abnormalities that predispose them to developing bulging eyes. These may be inherited traits or mutations that affect eye development.
6. Trauma or Injury: Physical trauma or injury to the eye area, such as damage caused by aggressive tankmates or improper handling, can result in bulging eyes.
7. Environmental Factors: Certain environmental factors, such as poor water quality, extreme temperature fluctuations, or chemical imbalances in the aquarium water, can stress the fish and make them more susceptible to eye infections or other conditions that lead to bulging eyes.
8. Blindness: In some cases, bulging eyes may also be associated with vision problems or blindness in the betta fish.
It's important to note that bulging eyes in a betta fish are a symptom of an underlying health issue and require proper diagnosis and treatment. If you notice bulging eyes in your betta, it's best to consult with an experienced veterinarian or fish expert to determine the cause and provide appropriate care to help the fish recover.