Why Grapes Are Dangerous for Cats. The Shocking Risks of Feeding Grapes to Your Feline Friend

Grapes Can Cause Kidney Failure in Cats

Grape and raisin consumption can lead to sudden kidney failure in cats. Even a small amount can be dangerous. The toxic compound in grapes is unknown. According to the ASPCA, as little as a handful of raisins or grapes can make a cat sick. There does not seem to be a minimum toxic amount, so it is safest to avoid feeding cats grapes altogether

Grapes and raisins contain an unknown toxin that can damage a cat’s kidneys. As the kidneys fail, they are unable to remove waste products from the blood, causing signs like vomiting, diarrhea, and lethargy[1]. Within 24-72 hours of ingestion, acute kidney failure develops, which can quickly become life-threatening.

The toxic compound in grapes and raisins that causes kidney failure in cats is not yet known. No other fruits or vegetables are known to have the same effect. Until researchers can isolate the toxin, it’s best to avoid giving grapes or raisins to cats at all.

Signs of Grape/Raisin Toxicity

Some of the most common signs of grape/raisin toxicity in cats include:

  • Vomiting – One of the first signs is often repetitive vomiting shortly after ingestion.

  • Diarrhea – Grapes can cause sudden onset of diarrhea in cats.

  • Lethargy – Affected cats often become very lethargic and weak.

  • Loss of appetite – Toxicity frequently causes a reduced appetite or complete loss of appetite.

  • Increased thirst and urination – Cats may drink excessively and urinate more frequently due to developing kidney issues.

  • Dehydration – Vomiting, diarrhea and increased urination can quickly lead to dehydration.

According to PetMD, signs of grape/raisin toxicity typically develop within 24 hours of ingestion [1]. Cat owners should watch for these symptoms carefully after potential exposure.

Why Grapes Are Toxic

The exact compound that causes toxicity in grapes is unknown. However, research indicates that oxidative damage likely plays a role in their toxicity to cats (Source 1). Grapes contain resveratrol, a compound that can have antioxidant effects at lower doses but become pro-oxidant at higher doses, leading to cell damage (Source 2). Additionally, the skin and seeds of grapes may contain the toxic substance, so even seedless grapes can pose a risk.

Amount Needed for Toxicity

As little as a grape or two can cause kidney failure in cats. The exact toxic dose depends on the individual cat and factors like size and health conditions. According to PetMD, ingestion of as little as 4-5 grapes or raisins within 24 hours can be fatal for cats. Smaller cats and kittens are at higher risk.

Grapes contain unknown toxins that can cause rapid kidney failure. Even a small amount can be extremely dangerous. Cats’ kidneys are not as effective at filtering toxins as dogs’ kidneys. Therefore, what may be a harmless amount for a dog can quickly cause kidney dysfunction in cats.

If you notice your cat has eaten grapes or raisins, take action immediately even if only 1-2 were ingested. Don’t wait for symptoms to appear, as irreversible kidney damage can occur within 24 hours.


If a cat is showing signs of grape or raisin toxicity, the veterinarian will run several diagnostic tests to confirm the diagnosis and assess any damage. These include:

  • Bloodwork to check kidney function – The vet will look for elevated kidney values such as blood urea nitrogen (BUN) and creatinine, which indicate kidney damage or failure. They may also check electrolyte levels.
  • Urine tests – Urinalysis can show if there is protein or crystals in the urine, which can indicate kidney issues.
  • Imaging of kidneys/bladder – X-rays, ultrasound, or CT scans can check for abnormalities or blockages in the urinary tract.

The combination of clinical signs, bloodwork, and imaging will allow the vet to confirm grape/raisin toxicity and determine the extent of kidney damage for proper treatment.


The mainstay of treatment for grape and raisin toxicity in cats is aggressive IV fluid therapy to flush toxins from the body and support kidney function. Vets will administer intravenous fluids for at least 48 hours, and often longer if kidney values remain elevated. The fluids help to flush out the kidneys and prevent kidney damage by diluting the toxins and encouraging urination.

Vets may also administer antioxidants intravenously, such as N-acetylcysteine. Antioxidants help combat the free radicals released when the grapes and raisins damage the kidneys. This helps minimize kidney damage.

Anti-nausea medication like maropitant or ondansetron is often given to control vomiting. Vomiting can lead to dehydration, which is problematic as keeping the patient hydrated is key. The anti-nausea medication allows the cat to keep down the IV fluids and get the flush their system needs.


The prognosis for cats who have ingested grapes or raisins depends on the timing of treatment and amount ingested. The sooner treatment is started after ingestion, the better the chances of recovery [1]. However, grape and raisin toxicity can be fatal without prompt treatment [2]. The toxins in grapes and raisins damage the kidneys, and this kidney damage may be permanent even if the cat survives the initial toxicity. With aggressive treatment started within the first 12-24 hours, many cats make a full recovery. However, those who develop oliguric renal failure have a guarded prognosis and may require lifelong kidney care and monitoring.


The best way to prevent grape and raisin toxicity in cats is to keep grapes and raisins completely away from your cat. Do not offer grapes or raisins to cats as treats or allow access to foods containing these ingredients. Carefully monitor trash and compost bins to ensure cats cannot access discarded stems, peels, or raisins.

Avoid offering cats any fruits, vegetables, or foods containing grape extracts or raisin products. Read all ingredient labels carefully to check for grape, raisin, or wine derivatives. Even small amounts found in breads, cereals, trail mixes or other human snacks can pose a danger.

Cats are adept at getting into places where food is stored, so securing grapes, raisins, and products containing them in tightly sealed containers inaccessible to pets is crucial. Attentive monitoring and prevention are the keys to keeping cats safe from grape and raisin toxicity.

Safe Fruit Alternatives for Cats

While grapes and raisins can be toxic for cats, there are many other fruits that are safe and healthy for feline consumption in moderation. Some cat-safe fruit alternatives include:

Bananas – Bananas are a great source of potassium and fiber. The high moisture content also helps with hydration. Just be sure to only feed small, bite-sized pieces without the peel.

Blueberries – These tiny fruits are packed with antioxidants, vitamin C, fiber and manganese. The serving size should be limited to just a few blueberries per day.

As a treat alternative to grapes or raisins, consider shelf-stable cat treats made with natural fruit flavors, like banana or blueberry. Single ingredient freeze-dried treats made from 100% raw fruits or meat are also a great option. Just be sure to follow package instructions and feed the appropriate serving size.

When giving cats fruit, moderation is key. Fruits should only account for 10% or less of a cat’s daily caloric intake. Always monitor your cat’s reaction to new foods as well.

What to Do if Ingestion Occurs

If your cat has ingested grapes or raisins, it is crucial that you seek emergency veterinary care immediately. Even a small amount can be toxic, so do not wait to see if symptoms develop.

If ingestion was very recent, you may need to induce vomiting before bringing your cat to the vet. Use 3% hydrogen peroxide, given orally at a dosage of 1 teaspoon (5 mL) per 5 lbs (2.3 kg) of body weight. Do not induce vomiting if it has been more than a couple hours since ingestion. Never induce vomiting unless instructed to do so by a veterinarian or poison control expert.

Call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435 right away if you suspect your cat has eaten grapes or raisins. Bring the packaging with you to the vet, if available, to indicate the amount ingested.

With prompt veterinary treatment, the prognosis is often good if treated early. However, acute kidney failure can develop within 24 hours after ingestion, so immediate veterinary care is crucial.

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