Side Effects of Feeding Fish to Cats Long-Term
📝 Summary
Long-term fish feeding harms cats: fish thiaminase destroys vitamin B1, fish drains vitamin E, and fish-liver phosphorus blocks calcium absorption. It also makes cats addicted and picky. Supplement B1, E, and calcium if fish is on the menu.
1 Side Effects of Long-Term Fish Feeding
I. Thiamine (Vitamin B1) Depletion
Thiamine (vitamin B1) is a sulfur compound and a coenzyme for pyruvate oxidation; it drives carbohydrate metabolism. Fish is rich in thiaminase, an enzyme that destroys B1 and causes deficiency. Without B1, pyruvate and lactate build up unoxidized and rise in blood and tissue. Cats may lose appetite and vomit; severe cases bring nerve disorders, paralysis, collapse, even heart failure and death.
II. Vitamin E Deficiency
Vitamins regulate physiology—boosting nerve function and building enzyme systems. Some need not come from food, but vitamin E must be supplemented through diet. Fish drains the body’s vitamin E; deficiency causes poor growth, lowered fertility, hard pregnancy, and miscarriage, and may bring anorexia and muscle wasting. Long-term feeding of deep-sea fish or tuna easily causes this.
III. Calcium Deficiency
Fish liver is high in phosphorus, which suppresses calcium absorption, so fish-eating cats get calcium deficiency. Calcium matters for bones, muscles, and nerves; deficiency blocks growth and development. If your cat loves fish, supplement calcium—chicken necks and wings are good sources.
Eating fish long-term is also addictive and leads to severe picky eating, which harms health. Keep a balanced diet and don’t spoil the cat. If you have other related questions, you can also consult an online veterinarian.
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