# Kitten Is Sick: Signs, Causes, and What to Do A kitten is sick when it stops acting like a normal kitten. Healthy kittens eat well, play hard, and sleep in between. If yours is hiding, refusing food, or unusually quiet, something is likely wrong and it needs a closer look. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - A kitten that misses even one or two meals, hides, or seems painful should be seen by a veterinarian the same day. - Young kittens get sick faster than adult cats because their bodies have very little reserve. - Newborn kittens are prone to low blood sugar, which can be life threatening, so weakness in the first days of life is always an emergency [1]. - Most mild diarrhea in kittens is self limiting and responds to supportive care with fluids and nutrition, but testing helps rule out serious causes [2]. - Keep a sick kitten warm, offer water, and do not give human medicines or antibiotics on your own. ## What a Sick Kitten Looks Like and What Is Normal Kittens sleep a lot. A healthy kitten may sleep 16 to 20 hours a day, then wake up hungry and play with real energy. That rhythm matters. A kitten that sleeps more but still eats and plays is usually fine. A kitten that sleeps more and stops eating is not. Normal kitten behavior includes a strong appetite, steady weight gain, bright eyes, and interest in toys and people. Kittens need a lot of attention, including feeding, socialization, and veterinary care [3]. A kitten that is being cared for well still gets sick sometimes, so behavior is your best early warning. Signs that a kitten is sick include: - Refusing food or nursing less - Hiding in closets, under beds, or behind furniture - Lethargy or weakness - Vomiting or diarrhea - A dull coat, sunken eyes, or dry gums - Crying, restlessness, or guarding the belly - Breathing that looks fast, open mouthed, or labored Owners often search for answers after a kitten is sick once or twice. One episode of vomiting or one loose stool in an otherwise bright, eating kitten is often not an emergency. Repeated episodes, or any episode with lethargy or appetite loss, changes the picture. If your kitten has loose stools, our guide to [Kitten Diarrhea: Causes, Safe Home Care, and Emergency Signs](/knowledge/veterinary-medicine/digestive-and-urinary-care/kitten-diarrhea-causes-and-care) walks through what to watch. For vomiting specifically, see [Cat Vomiting: When to Worry and What to Do](/knowledge/veterinary-medicine/online-vet-and-care-costs/cat-vomiting-when-to-worry-what-to-do). ## Why a Kitten Is Getting Sick: Common Causes by Age The likely cause depends heavily on age. A two week old kitten and a four month old kitten have very different risks. ### Newborn to 4 weeks Newborn kittens have an underdeveloped metabolism. They burn through liver sugar reserves quickly and cannot make glucose well, which makes low blood sugar a real danger in the first days of life [1]. Low blood sugar can be fatal, and low readings do not always cause obvious signs [1]. Any newborn that feels cold, limp, or will not nurse needs emergency care. ### 4 weeks to 8 weeks Kittens can generally leave their mother and littermates once they are weaned, starting at 6 to 7 weeks old [3]. Around this time, stress, diet changes, and parasites often show up as diarrhea or vomiting. Maternal immunity passed through nursing is fading, and it declines slowly over time [3]. That leaves a window where a kitten can catch something before vaccines take hold. ### 2 months to 6 months Vaccination usually begins at 2 to 3 months old, timed so the kitten gets an effective dose soon after maternal protection is gone [3]. Until the full vaccine series is complete, keep your kitten away from unvaccinated cats, because that contact is a real disease risk [3]. Common illnesses in this age group include upper respiratory infections, intestinal parasites, and panleukopenia. ### Any age Some serious diseases can appear at any age. Feline infectious peritonitis (FIP) was historically linked to a poor prognosis and high mortality, but remission is now possible with newer treatment [4]. Cancer also occurs in cats, and signs like a lump, weight loss, or appetite change should be checked, since diagnosis often starts with a needle biopsy or surgery to examine the tissue [5]. A cat with cancer may need palliative care focused on pain relief and quality of life [5]. | Cause | Typical clues | How urgent | |---|---|---| | Low blood sugar (newborns) | Weakness, limpness, not nursing, cold | Emergency now [1] | | Intestinal parasites | Diarrhea, pot belly, poor coat | Same day to 48 hours | | Upper respiratory infection | Sneezing, eye or nose discharge, appetite loss | Same day | | Acute diarrhea | Loose stool, often self limiting | Monitor 24 hours, call if worse [2] | | FIP | Fever, weight loss, fluid in the belly or chest | Same day | | Cancer | Lump, weight loss, vomiting, lethargy | Same day to routine [5] | | Bacterial infection | Chronic cough, lethargy, weight loss | Same day | ## Red Flags That Mean Emergency Care Now Some signs mean you should not wait. Go to an emergency clinic if your kitten: - Will not eat or drink for more than 12 hours - Is limp, cold, or unresponsive - Breathes with an open mouth or with obvious effort - Has repeated vomiting or diarrhea, especially with blood - Has a distended, painful belly - Has a seizure or collapses - Is a newborn that will not nurse Newborn weakness is at the top of this list because low blood sugar in the first days of life can be fatal [1]. Do not try to feed a limp kitten by mouth. Call ahead so the clinic can prepare. ## Safe Things You Can Do at Home While You Wait Home care buys time. It does not replace a diagnosis. **Keep the kitten warm.** Use a heating pad on low under a towel, or a warm rice sock. Cold kittens cannot digest food well. **Offer water and food often.** Small amounts, frequently. A kitten that will not eat at all needs a vet. **Do not give human medicines.** Never give acetaminophen, ibuprofen, or human antibiotics. Doses for kittens are calculated by your veterinarian based on weight and health, and many human drugs are toxic to cats. **Skip routine antibiotics.** For uncomplicated acute diarrhea, current evidence argues against routine antibiotic use because it drives resistance and disrupts the gut microbiome [2]. Targeted therapy is reserved for systemic or bacterial infections [2]. **Keep notes.** Write down when the kitten last ate, what the stool looked like, and how many times it vomited. This helps your vet a lot. **Isolate if you have other cats.** Use separate bowls and litter boxes, and wash your hands between handling. If the problem is diarrhea, our article on [Cat Diarrhea: How to Tell If It's Serious and What to Do](/knowledge/veterinary-medicine/preventive-and-routine-care/cat-diarrhea-serious-what-to-do) covers home care in more detail. If your kitten is drinking far more than usual, see [Cat Drinking a Lot of Water: Is It a Sign of Illness?](/knowledge/veterinary-medicine/vet-visit-decisions/cat-drinking-lot-water-sign-illness). ## What Your Veterinarian Will Check and Test Your vet starts with a full physical exam: weight, temperature, hydration, gum color, heart and lung sounds, and a careful feel of the belly. Weight is a big deal in kittens. A kitten that has lost weight since the last visit is a kitten that is losing ground. Testing depends on the signs. Common steps include: - A fecal exam for parasites - Blood glucose, especially in newborns [1] - Blood work to check organ function and infection - X-rays or ultrasound if the belly is painful or a mass is felt - A needle biopsy if a lump is found, which removes a tiny tissue sample to examine cells under a microscope [5] Treatment is matched to the cause. Supportive care with fluids and nutrition is the backbone for most mild gut upset [2]. Antiemetics may be used for vomiting, and hygiene matters a great deal in a multi cat home [2]. For bacterial infections, treatment can be long. In two cats with a Mycobacterium caprae infection, triple antimicrobial therapy was given for 9 and 11 months, and both made complete recoveries [6]. That is an extreme example, but it shows why guessing at treatment is a bad idea. ## Prevention and Monitoring Prevention is mostly about timing and hygiene. - Follow the vaccine schedule. Start at 2 to 3 months old and complete the series [3]. - Keep your kitten away from unvaccinated cats until vaccines are done [3]. - Weigh your kitten weekly on a kitchen scale and write it down. - Deworm on your vet's schedule. - Feed a kitten appropriate diet, not adult cat food. - Watch for changes in appetite, play, and litter box habits. Kittens are fragile and can decline within hours. A daily check of appetite, energy, and stool gives you the earliest possible warning. ## Limitations and When to Contact a Veterinarian This article cannot tell you what is wrong with your specific kitten. Only a veterinarian who examines your kitten can do that. Call an emergency clinic now if your kitten is limp, cold, struggling to breathe, having seizures, or will not eat or drink for more than 12 hours. Newborn weakness is always an emergency because low blood sugar can be fatal [1]. Call your veterinarian the same day if your kitten is vomiting or having diarrhea more than twice, hiding, crying when touched, or has a fever. A kitten that is sick twice in a day is a kitten that needs a phone call at minimum. Schedule a routine visit if your kitten is eating and playing but has a mild change, such as one soft stool or slightly less energy. If a lump is found, diagnosis typically starts with a needle biopsy or surgery to examine the tissue [5]. ## Frequently Asked Questions ### How do I know if my kitten is seriously sick or just tired? A tired kitten still eats. A seriously sick kitten stops eating, hides, and does not want to play. If appetite and play are both gone, treat it as serious and call your vet. ### Can a kitten get sick from being around other cats? Yes. Until the full vaccine series is complete, keep your kitten away from unvaccinated cats, because that contact can spread disease [3]. Maternal immunity fades over time, which leaves a gap before vaccines fully protect your kitten [3]. ### Should I give my kitten antibiotics for diarrhea? No. For uncomplicated acute diarrhea, current evidence argues against routine antibiotic use because it promotes resistance and disrupts the normal gut bacteria [2]. Antibiotics are reserved for systemic or bacterial infections and are chosen by your veterinarian [2]. ### Why do newborn kittens get weak so fast? Newborn kittens have an immature metabolism, burn through liver sugar stores quickly, and cannot make glucose well [1]. Their blood sugar can swing in the first days of life, and low levels can be fatal even without obvious signs [1]. Weakness in a newborn is an emergency. ### What should I bring to the vet visit? Bring a fresh stool sample if there is diarrhea, a note of when your kitten last ate and vomited, and any medication or food labels. If you have other cats, mention that too, since hygiene and isolation matter in a multi cat home [2]. ## Related Articles - [Kitten Diarrhea: Causes, Safe Home Care, and Emergency Signs](/knowledge/veterinary-medicine/digestive-and-urinary-care/kitten-diarrhea-causes-and-care) - [Cat Bad Breath: When Is It a Sign of Illness?](/knowledge/veterinary-medicine/vet-visit-decisions/cat-bad-breath-when-to-worry) - [Cat Diarrhea: How to Tell If It's Serious and What to Do](/knowledge/veterinary-medicine/preventive-and-routine-care/cat-diarrhea-serious-what-to-do) - [Cat Vomiting: When to Worry and What to Do](/knowledge/veterinary-medicine/online-vet-and-care-costs/cat-vomiting-when-to-worry-what-to-do) - [Cat Drinking a Lot of Water: Is It a Sign of Illness?](/knowledge/veterinary-medicine/vet-visit-decisions/cat-drinking-lot-water-sign-illness) - [Cat Vomiting and Diarrhea with Blood: Emergency Signs](/knowledge/veterinary-medicine/digestive-and-urinary-care/cat-vomiting-diarrhea-blood-emergency) - [Sick Kitten Signs: Behavior, Crying, and Lethargy Explained](/knowledge/veterinary-medicine/symptom-guides/sick-kitten-signs-behavior) - [Sick Kitten Symptoms: A Checklist for Worried Owners](/knowledge/veterinary-medicine/symptom-guides/sick-kitten-symptoms-checklist) - [Sick Kitten: What to Do and Safe Home Care](/knowledge/veterinary-medicine/pet-care/sick-kitten-what-to-do) - [Cat Respiratory Infections: Etiology, Clinical Signs, Zoonotic Potential, and Management](/knowledge/bacteria/pet-bacteria/cat-respiratory-infections-etiology-clinical-signs-zoonotic-potential-management) ## References 1. [Reassessing neonatal hypoglycemia in kittens: clinical relevance beyond the laboratory value](https://pubmed.ncbi.nlm.nih.gov/42790675/). Topics in companion animal medicine, 2026. 2. [From Diagnosis to Resolution: A Practical Guide to Acute Diarrhea in Veterinary Patients](https://pubmed.ncbi.nlm.nih.gov/41763984/). The Veterinary clinics of North America. Small animal practice, 2026. 3. [Kitten Care - Cat Owners](https://www.merckvetmanual.com/cat-owners/caring-for-cats/kitten-care). Merck Veterinary Manual. 4. [Successful treatment and long-term follow-up of a young cat with feline infectious peritonitis and renal lymphoma](https://pubmed.ncbi.nlm.nih.gov/41246438/). Open veterinary journal, 2025. 5. [Common Cat Diseases](https://www.aspca.org/pet-care/cat-care/common-cat-diseases). ASPCA Animal Poison Control Center. 6. [Successful Treatment of Mycobacterium caprae Infection in Two UK Cats](https://pubmed.ncbi.nlm.nih.gov/42675021/). Veterinary medicine and science, 2026. ## 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)