Grapes / Raisins / Currants

Symptoms reported in cats

Most serious first.

1. 1
   Oliguria (Decreased Urine) or Anuria (No Urine Production) 12–72 hours (As the condition worsens). · This indicates that the kidneys have stopped functioning (shut down). Without immediate emergency intervention, this stage is often fatal. Some cats may be unaffected by grapes, while others develop this condition rapidly; the exact reason for individual sensitivity varies.
2. 2
   Vomiting Within 12 hours of ingestion. · This is typically the first clinical sign of toxicity. The vomit may contain pieces of the undigested fruit.
3. 3
   Lethargy, Weakness, or Depression 12–24 hours. · The cat may appear unusually tired, hide, or refuse to move as kidney function begins to decline and uremic toxins build up in the blood.
4. 4
   Increased Thirst (Polydipsia) and Increased Urination (Polyuria) Initial 24 hours. · Early in the poisoning process, the kidneys may lose the ability to concentrate urine, leading to excessive drinking and urination before shutting down.Acute Kidney Failure (Anuria)
5. 5
   Poor Appetite or Refusal to Eat 12–24 hours. · Cats often refuse food as nausea sets in from the elevated kidney toxins in their blood.
6. 6
   Diarrhea 12–24 hours (Often follows the initial vomiting). · Occurs as the toxins move through the digestive tract; may contribute to dehydration which exacerbates kidney stress.

Important notes

Grapes, raisins, sultanas, and currants are highly dangerous for cats. There is no known safe amount. Even one grape or a few raisins may be enough to cause a serious problem in some cats. The exact toxin is still not fully confirmed, though tartaric acid is one leading suspect. The main danger is sudden kidney injury. Because cats react unpredictably, a small amount can be risky even if another cat once seemed fine after eating more. Early signs may include vomiting, diarrhea, low energy, not eating, belly pain, or increased thirst. Kidney problems can develop later. If your cat eats any grape, raisin, sultana, or currant, contact a veterinarian or pet poison helpline immediately instead of waiting for symptoms.

• Toxic compounds: likely tartaric acid or related compound; exact mechanism still under investigation
• Mechanism: direct nephrotoxicity — causes acute tubular injury leading to kidney failure within 24–72 hours
• Symptoms Phase 1 (within 6h): vomiting, diarrhea, abdominal pain, lethargy; Phase 2 (24–72h): acute kidney failure with decreased urination, loss of appetite, weakness
• Raisins and dried currants are more dangerous by weight due to concentration; currants (Zante) are similarly toxic
• Any grape or raisin ingestion warrants immediate veterinary attention — do not wait for symptoms