# Why Does My Cat Quiver? Tail Quivering and Body Shakes A cat who quivers her tail is usually excited and happy to see you. A cat whose body trembles while standing, resting, or walking may have a medical problem that needs a veterinarian. This article explains why do cats quiver their tails, what normal quivering looks like, and how to tell a harmless wiggle from a warning sign. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - A tail that quivers upright and vibrates fast is usually a friendly greeting, often aimed at a person or another cat the cat likes. - A whole-body tremor that happens at rest, while standing, or while walking is more likely to be medical. - Tremors in cats are most often linked to degenerative brain disease, feline infectious peritonitis, a congenital liver shunt, poisoning, or nerve disease [1]. - Record a short video of the quiver or shake. It helps your veterinarian see what you see. - Call your vet the same day if the shaking is new, comes with weakness, vomiting, or appetite loss, or if your cat seems painful or unsteady. ## What Tail Quivering and Body Shaking Look Like ### Tail quivering Tail quivering is a fast, fine vibration of a tail held straight up. The tail may look like it is buzzing. The cat often stands tall, kneads with her front paws, and looks right at you. This is a greeting. It is common when a cat approaches a person she trusts, when she is waiting for food, or when she rubs against your leg. Tail quivering is also part of normal cat communication. Cats spray urine on vertical objects by raising the tail, and sprayed urine acts as a scent mark for territory [2]. A quivering tail during a friendly greeting is not the same as spraying, but both use the raised-tail posture. If your cat quivers her tail at you and then rubs your leg, that is social behavior, not a medical sign. ### Body shaking and tremors A body tremor is a rhythmic, repeated muscle movement. It can affect the whole body, the head, one limb, or the back legs only. Tremors can be fast or slow, constant or episodic. Some cats tremble only when they stand against gravity. Others tremble at rest. One report described an 11-month-old cat with a tremor in both back legs that only appeared when standing or when the knee was actively extended. The tremor disappeared when the leg was lifted and not bearing weight. Testing confirmed a low-frequency tremor of about 6 cycles per second, and the cat was diagnosed with pseudo-orthostatic tremor. The cat stayed playful and able to walk, but often lay on her side and had trouble jumping [3]. That case shows how specific tremors can be. A tremor that only happens in one position is different from a cat who shakes all over. ## Why Do Cats Quiver Their Tails? Normal and Benign Reasons Tail quivering in a healthy cat is usually a good sign. Common benign reasons include: - Greeting a favorite person or cat - Anticipation of food, treats, or play - Excitement during petting or brushing - A friendly hello when your cat jumps onto your lap or bed Kittens quiver too. A kitten may quiver her tail when she sees her mother or a littermate, or when she is learning to greet people. Kittens also have less muscle control than adults, so small tremors can show up during excitement or when they are tired. If a kitten quivers only during happy moments and is eating, playing, and growing well, it is usually nothing to worry about. Some cats quiver their tail when they are about to spray. If your cat is intact or was recently neutered, watch for urine on walls or furniture. Sprayed urine has a strong odor because proteins in it help it stick to vertical surfaces [2]. Neutering usually reduces spraying, but it does not always stop it. ## Main Causes of Body Tremors in Cats Tremors are a common neurological complaint in cats, and the list of possible causes is long. In a review of 105 cats with tremors, the most common diagnoses were degenerative encephalopathy (19 of 105 cats, about 18 percent), feline infectious peritonitis (17 of 105, about 16 percent), congenital portosystemic shunt (17 of 105, about 16 percent), intoxication (16 of 105, about 15 percent), and polyneuropathy (8 of 105, about 8 percent) [1]. The most common degenerative brain diseases were suspected cerebellar cortical degeneration and lysosomal storage diseases, and these often caused tremors when the cat tried to do something on purpose, like eat or walk to a target [1]. | Cause | Typical clues | How urgent | |---|---|---| | Friendly excitement (tail quiver) | Tail up and buzzing, cat rubs you, purrs, wants food or petting | Not urgent | | Degenerative brain disease | Tremor that gets worse with intentional movement, wobbling, young cat, slow progression | See your vet soon | | Feline infectious peritonitis (FIP) | Fever, poor appetite, weight loss, belly swelling, eye or brain signs | See your vet now | | Congenital portosystemic shunt (liver shunt) | Tremor at rest, head tremor, small cat, drooling, sluggish after meals | See your vet now | | Poisoning or toxin exposure | Sudden shaking, drooling, vomiting, wobbling, possible access to a toxin | Emergency | | Low blood sugar | Weakness, wobbling, collapse, small or very young cat, missed meals | Emergency | | Nerve or muscle disease (polyneuropathy) | Weak legs, trouble jumping, muscle wasting, trembling during movement | See your vet soon | | Pain | Trembling with hiding, tense belly, not eating, crying, reluctance to move | See your vet now | | Cold or stress | Shivering in a cold room, new environment, tense posture, normal appetite | Warm and calm the cat, call if it continues | ### Liver shunt and hepatic encephalopathy A congenital portosystemic shunt is an abnormal blood vessel that lets blood bypass the liver. This can cause hepatic encephalopathy, a brain condition that often shows up as tremors. In a review of 19 cats with hepatic encephalopathy from a congenital shunt, 17 had tremors when they arrived at the hospital. Tremors were the only neurological sign in 6 of the 19 cats. The tremors were generalized in 10 cats, limited to the head in 8 cats, and limited to one limb in 1 cat. Most tremors were episodic and not brought on on purpose, happening usually at rest, though some had features that appeared with intentional movement. Of the 14 cats with one-month follow-up, tremors stopped in 9 after surgery or medical treatment [4]. This matters because a liver shunt is treatable in many cats. If your cat trembles at rest, drools, seems dull after meals, or has a small body size, ask your veterinarian about testing for a shunt. ### Toxins and poisons Poisoning was the cause in about 15 percent of cats with tremors in one large review [1]. Common household toxins include certain plants, human medications, insecticides, and antifreeze. If you think your cat ate something toxic, call your veterinarian or a pet poison hotline right away. Do not wait for symptoms to get worse. ### Low blood sugar Low blood sugar can cause trembling, weakness, and collapse. It is more common in very young kittens, cats who have not eaten for a long time, and cats with certain illnesses. This is an emergency. A veterinarian needs to check your cat's blood sugar and treat it right away. ### Pain Pain can make a cat tremble. Cats hide pain well, so watch for other signs like hiding, a tense belly, not eating, growling when touched, or refusing to jump. If your cat trembles and seems painful, call your veterinarian the same day. ### Neurological and movement disorders Some tremors come from the nervous system itself. Pseudo-orthostatic tremor is one example, where the tremor appears only when the cat stands against gravity [3]. Other cats have polyneuropathy, which affects nerves and muscles and can cause weakness and trembling [1]. Some of these conditions are manageable but not curable. Your veterinarian can help you understand what to expect. ## Red Flags That Make It an Emergency Call an emergency veterinary hospital right away if your cat has any of these signs: - Sudden severe shaking or trembling that will not stop - Collapse, fainting, or inability to stand - Trouble breathing - Seizures or loss of consciousness - Known or suspected exposure to a toxin - Vomiting, drooling, or diarrhea with shaking - A body temperature that feels very cold or very hot - Trembling with a swollen belly, yellow gums, or yellow eyes - Trembling after a fall, hit, or other injury If your cat is trembling but alert, eating, and acting mostly normal, call your regular veterinarian for advice. A video of the shaking helps them decide how soon your cat needs to be seen. For head and ear shaking specifically, see [Why Is My Cat Shaking Her Head And Ears](/knowledge/veterinary-medicine/clinical-methods/why-is-my-cat-shaking-her-head-and-ears) and [Cats Ears Twitching And Shaking Head](/knowledge/veterinary-medicine/clinical-methods/cats-ears-twitching-and-shaking-head). If you are not sure whether the shaking is an emergency, [Cat Shaking or Trembling: Is It an Emergency?](/knowledge/veterinary-medicine/vet-visit-decisions/cat-shaking-when-emergency) walks through the decision. ## Safe Things You Can Do at Home While Waiting - Record a 30 to 60 second video of the quiver or shake. Note what your cat was doing at the time. - Write down when it started, how often it happens, and what makes it better or worse. - Keep your cat warm, calm, and in a quiet room. - Do not give any human medication. Many human drugs are toxic to cats. - Do not force food or water if your cat seems weak or unable to swallow. - Remove access to any possible toxin, such as plants, medications, or chemicals. - If your cat is wobbling, block stairs and high furniture to prevent a fall. - Call your veterinarian or a pet poison hotline if you suspect poisoning. Do not try to diagnose your cat at home. Tremors have many causes, and some are serious. Your veterinarian has the tools to sort it out. ## What Your Veterinarian Will Check and Test Your veterinarian will start with a full physical and neurological exam. They will watch your cat stand, walk, and jump if possible. They will check reflexes, balance, vision, and muscle strength. They will also feel your cat's belly, check the gums, and look for signs of pain. Testing may include: - Blood work to check blood sugar, liver values, and organ function - Bile acids test to look for a liver shunt - Urine tests - Infectious disease testing, including for feline infectious peritonitis - Imaging such as X-rays or ultrasound - Advanced imaging such as MRI or CT if a brain or spinal problem is suspected - Nerve and muscle testing in some cases In the pseudo-orthostatic tremor case, needle electromyography confirmed a low-frequency tremor in both back legs while the cat was conscious [3]. That kind of testing is done by a specialist. Your veterinarian will decide what is needed for your cat. Treatment depends on the cause. Some cats improve with surgery or medical management. In the liver shunt review, tremors stopped in 9 of 14 cats with follow-up after surgery or medical treatment [4]. Other causes, like degenerative brain disease, may not have a cure, but your veterinarian can help manage symptoms and keep your cat comfortable. ## Prevention and Monitoring You cannot prevent every cause of tremors, but you can lower some risks. - Keep toxins, human medications, and harmful plants out of reach. - Feed a balanced diet and keep regular meal times, especially for kittens and small cats. - Keep up with wellness visits so your veterinarian can catch liver or nerve problems early. - Spay or neuter your cat to reduce spraying and some hormone-related behaviors. - Watch for changes in jumping, walking, or appetite. These can be early signs of a movement disorder. - If your cat has a known condition, follow your veterinarian's monitoring plan and keep a symptom log. If your cat only quivers her tail during happy greetings, you can relax. If the shaking involves the body, happens at rest, or comes with other signs, get veterinary help. ## Limitations and When to Contact a Veterinarian This article cannot tell you what is causing your cat's quiver or shake. Only a veterinarian who examines your cat can do that. Individual cases need a veterinarian. Contact your veterinarian the same day if your cat has new body tremors, seems weak or unsteady, is not eating, is hiding more than usual, or seems painful. Go to an emergency hospital now if your cat collapses, has trouble breathing, has a seizure, or may have eaten a toxin. Schedule a routine visit if your cat has a mild quiver that comes and goes, especially if it only happens during greetings or excitement. Bring a video and a written log. ## Frequently Asked Questions ### Why does my cat quiver her tail at me? She is likely greeting you. A tail held up and vibrating fast is a friendly signal, often seen when a cat approaches someone she likes or waits for food. If she also rubs against you or kneads, it is social behavior, not a health problem. ### Why do kittens quiver? Kittens quiver for the same friendly reasons adult cats do, and their muscles are still developing. A kitten who quivers during greetings, play, or feeding and is growing well is usually fine. If a kitten trembles at rest, seems weak, or stops eating, call your veterinarian. ### Can stress or cold make my cat shake? Yes. A cold room, a new environment, or a stressful event can make a cat shiver. Warm her up, give her a quiet place to settle, and watch her appetite and energy. If the shaking continues or she seems unwell, call your veterinarian. ### Is tail quivering the same as spraying? No. Tail quivering is a greeting. Spraying is a marking behavior where a cat backs up to a vertical surface and releases urine with the tail raised. Sprayed urine has a strong odor because proteins in it help it cling to surfaces [2]. Neutering reduces spraying but does not always stop it. ### What should I do if my cat's whole body is shaking? Call your veterinarian. Whole-body shaking can come from many causes, including brain disease, liver shunts, toxins, low blood sugar, and nerve disease [1]. Record a video, note when it happens, and keep your cat calm and warm while you arrange care. If she collapses or has trouble breathing, go to an emergency hospital right away. ## Related Articles - [Why Is My Cat Shaking Her Head And Ears](/knowledge/veterinary-medicine/clinical-methods/why-is-my-cat-shaking-her-head-and-ears) - [Cats Ears Twitching And Shaking Head](/knowledge/veterinary-medicine/clinical-methods/cats-ears-twitching-and-shaking-head) - [Cat Shaking or Trembling: Is It an Emergency?](/knowledge/veterinary-medicine/vet-visit-decisions/cat-shaking-when-emergency) - [Cat Shaking Head and Scratching Ears: Causes and Urgency](/knowledge/veterinary-medicine/vet-visit-decisions/cat-shaking-head-scratching-ears) - [Cat Shaking Head And Scratching Ear](/knowledge/veterinary-medicine/behavior/cat-shaking-head-and-scratching-ear) - [Why Is My Dog Shaking?](/knowledge/veterinary-medicine/symptom-guides/why-is-my-dog-shaking) - [Why Is My Cat Quivering? Causes of Tremors in Cats](/knowledge/veterinary-medicine/symptom-guides/why-is-my-cat-quivering) - [Why Does My Cat Vibrate? Tail Trembling and Purring Explained](/knowledge/veterinary-medicine/behavior/why-does-my-cat-vibrate) - [Tremors in Cats: Causes, Locations, and When to Worry](/knowledge/veterinary-medicine/symptom-guides/tremors-in-cats-causes) ## References 1. [Tremors in cats: 105 cases (2004-2023)](https://pubmed.ncbi.nlm.nih.gov/39701372/). Veterinary journal (London, England : 1997), 2025. 2. [Sprayed Urine Emits a Pungent Odor due to its Increased Adhesion to Vertical Objects via Urinary Proteins Rather Than to Changes in its Volatile Chemical Profile in Domestic Cats](https://pubmed.ncbi.nlm.nih.gov/38600408/). Journal of chemical ecology, 2024. 3. [Pseudo-orthostatic tremor in a cat](https://pubmed.ncbi.nlm.nih.gov/40186417/). Journal of veterinary internal medicine, 2025. 4. [Tremors in cats with hepatic encephalopathy-congenital portosystemic shunts or postattenuation neurological syndrome](https://pubmed.ncbi.nlm.nih.gov/39539156/). The Veterinary record, 2025. ## Further Reading - [Merck Veterinary Manual: Cat Owners](https://www.merckvetmanual.com/cat-owners) - [Cornell Feline Health Center: Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)