Identifying Tumors and Spinal Deformities in Koi

Growth Types

• Fatty tumors (lipomas): Soft, movable, benign.
• Cancerous tumors: Firm, invasive, may ulcerate.
• Fluid-filled cysts: Fluctuant, translucent.
• Bacterial granulomas (Fish TB): Hard, irregular, often multiple; chronic wasting.
• Viral (Lymphocystis): Cauliflower-like white/pink nodules; usually self-limiting.

The "S" Curved Spine

This is rarely a broken back. Causes include:

• Genetic deformity
• Nutritional deficiency (vitamin C, amino acids)
• Fish TB (mycobacteriosis)
• Parasitic encystment (rare)
• Electrocution or trauma

Next Steps

Photos are essential for remote diagnosis. Note color, texture, size, number of growths, and fish behavior. See "Why is my fish bent?" for more on spinal issues.