Cat Not Eating: Causes, What to Do, and When It's an Emergency
A cat that stops eating is not merely "being fussy". Inappetence in cats — particularly when it extends beyond 24 to 48 hours — is a genuine medical concern, and understanding why requires knowing something specific about feline physiology that distinguishes cats from most other domestic animals. This guide covers the common reasons cats stop eating, when the situation becomes urgent, what you can do at home, and why a cat that has not eaten for more than 48 hours needs veterinary attention regardless of how otherwise normal they appear.
Why Cat Anorexia Is Different — Hepatic Lipidosis
The most important thing to understand about a cat that is not eating is the risk of hepatic lipidosis — a condition specific to cats (and some other species) that makes prolonged food refusal a genuine medical emergency. When a cat's caloric intake drops significantly — particularly in an overweight cat — the body responds by mobilising fat reserves to meet energy needs. In cats, this mobilisation is inefficient, and fat accumulates in the liver at a rate the liver cannot process. The resulting fatty infiltration impairs liver function, which then reduces appetite further, creating a self-reinforcing cycle. Without intervention, hepatic lipidosis is fatal. With intervention — typically assisted feeding via an oesophagostomy tube placed under anaesthetic — most cats make a full recovery. The key is that intervention cannot wait until the cat is critically ill.
A cat that has not eaten adequately for more than 48 hours needs veterinary assessment regardless of any other signs. A cat that has not eaten for 72 hours or more is at significant risk. For overweight cats — which represents a substantial proportion of the domestic cat population — this timeline may be even shorter. This is not a situation to manage at home with appetite stimulants purchased online.
Common Reasons Cats Stop Eating
The causes of inappetence in cats are numerous. Dental pain is among the most common — cats with dental disease, tooth resorption, gingivitis or an abscess often reduce food intake gradually or suddenly and may show signs of oral discomfort (drooling, pawing at the mouth, dropping food, preference for soft food over dry). Dental disease is endemic in the domestic cat population and is persistently underdiagnosed because cats mask pain effectively and owners may not inspect the mouth regularly.
Respiratory illness is another common cause — cats rely heavily on their sense of smell to find and identify food, and a cat with an upper respiratory infection and a blocked nose may completely lose interest in food simply because they cannot smell it. This is particularly common in kittens and in multi-cat households where respiratory viruses spread easily. Offering warm, strong-smelling food (lightly warmed wet food) can help stimulate appetite in cats with mild URI while the infection resolves.
Gastrointestinal problems — nausea, vomiting, constipation, inflammatory bowel disease, gastroenteritis — are frequent causes of inappetence. The cat that eats breakfast, vomits, and then refuses subsequent meals may be experiencing nausea that the owner does not realise is ongoing. Kidney disease is a very common condition in middle-aged to older cats (estimated to affect around 30% to 40% of cats over 10 years) and consistently causes reduced appetite due to the nausea produced by accumulating uremic toxins. Any older cat that has gone off food warrants prompt investigation for chronic kidney disease.
Hyperthyroidism — overproduction of thyroid hormone — paradoxically often causes increased appetite in affected cats, though some cats show a more complex picture where appetite is variable. Liver disease, pancreatic disease (including pancreatitis, which is more common in cats than historically appreciated), and cancer can all cause inappetence. Stress and anxiety are significant causes — a new pet in the household, a house move, a change in routine, or any environmental disruption can cause a sensitive cat to stop eating. Environmental causes are more likely when the inappetence is accompanied by other signs of stress (hiding, reduced grooming, litter tray avoidance) and begins clearly in temporal relation to a change.
Food Aversion
A specific and clinically important phenomenon in cats is food aversion — where a cat develops a persistent dislike of a food that was presented while the cat was feeling ill. If a cat is nauseated and eats its regular food at that time, the negative experience can create an association that causes the cat to refuse that food permanently even after recovery. This is a significant practical problem: a cat recovering from illness that needs to eat a specific prescription diet may develop aversion to that diet if it is offered before the nausea is adequately controlled. Managing nausea before introducing new foods during illness is therefore important for long-term dietary management.
What to Do When Your Cat Stops Eating
The first step is to observe for other signs. Is the cat still drinking? Still using the litter tray (and are the urine and faeces normal in appearance)? Still grooming? Still interested in their surroundings? Is there vomiting or diarrhoea? Have there been any recent changes in the household or environment? Are there signs of pain — reluctance to jump, abnormal posture, guarding of any body part? These observations are valuable information for a veterinarian and help distinguish a potentially minor, self-resolving cause from a more serious one.
For a cat that has missed one meal but appears otherwise completely normal, monitoring for 12 to 24 hours while offering alternative foods is reasonable — different textures, temperatures, and flavours can stimulate interest. Warming wet food slightly intensifies its smell. Offering food from the hand rather than a bowl can encourage hesitant eaters. Moving the food bowl away from the litter tray (cats prefer to eat and eliminate in different locations) can improve uptake. However, any cat that has not eaten for 48 hours, any cat showing other symptoms, any kitten or senior cat that has missed more than one meal, and any overweight cat that has reduced food intake should be seen by a veterinarian without delay.
What a Vet Will Do
The veterinary assessment for a cat not eating will typically include a full physical examination, assessment of body condition and weight, and depending on the clinical picture, blood and urine tests, imaging (X-rays or ultrasound), and dental examination under anaesthesia if oral disease is suspected. Treatment depends on the underlying cause but may include fluid therapy for dehydration or renal support, antiemetics (anti-nausea medication), appetite stimulants (mirtazapine is commonly used in cats), antibiotic treatment for infection, dental treatment, dietary management, and in severe cases of hepatic lipidosis, placement of a feeding tube to provide nutrition while the underlying condition is treated and the liver recovers.
Appetite Stimulants at Home
Several approaches can help stimulate appetite in cats that are mildly inappetent due to recoverable causes. Mirtazapine is available as a transdermal ear gel (Mirataz) or as a tablet — by prescription — and is effective in stimulating appetite in cats. Capromorelin (Elura) is a newer veterinary appetite stimulant specifically for cats. These require a veterinary prescription and should not be used in place of investigating the cause of the inappetence. At home without medication, rotation of food types, textures and temperatures, trying baby food (plain chicken or turkey without onion, garlic or seasoning), and offering from the hand or a flat plate rather than a deep bowl (some cats dislike whisker pressure from deep bowls — "whisker fatigue") can help in mild cases.
Summary
A cat that is not eating is never a situation to monitor indefinitely. Cats face the specific risk of hepatic lipidosis with sustained food refusal, making timely intervention important. Common causes range from dental pain and respiratory illness to kidney disease and environmental stress. Observe for other signs, offer alternative foods, but do not delay beyond 48 hours without veterinary consultation — and for kittens, seniors, and overweight cats, the threshold for seeking help should be lower. The sooner the underlying cause is identified and addressed, the better the outcome and the lower the risk of the serious secondary complications that prolonged anorexia creates.