How to Tell if your Cat is Sick?
Cats are masters of disguise when it comes to illness. Unlike dogs, who may outwardly show distress, cats often hide their symptoms until a condition has progressed significantly. As a dedicated pet parent, recognising the difference between normal feline behaviour and early warning signs of illness or stress is essential for your cat’s well-being.
What’s Normal Cat Behaviour? Understanding Behaviour by Life Stage
Before we dive into abnormal behaviours, it’s important to understand what’s typical for cats at different life stages:
Kittens (0–6 months)
Expect boundless energy, playful curiosity, and frequent bursts of activity followed by deep sleep. Kittens are learning the ropes, socialising, and exploring their world.
Junior Cats (7 months–2 years)
These “teenage” cats are still playful but may test boundaries and exhibit mood swings.
Adult Cats (3–6 years)
By this stage, most cats settle into a consistent routine, engaging in regular play but with less intensity than kittens.
Mature & Senior Cats (7+ years)
Older cats tend to slow down, sleep more, and may become less interested in play. However, they should still groom themselves and interact with their environment.
When to Worry: Signs of Illness and Stress in Cats
Since cats instinctively mask when they are feeling sick or stressed, even subtle changes in their behaviour can be red flags. Identifying these early signs can prevent more serious health complications.
Signs of Stress in Cats
Stress can significantly impact a cat’s health and may manifest in behavioural changes. Common stressors include changes in routine, new pets, moving homes, or loud noises.
Here are some signs that may indicate your cat is feeling stressed:
- Hiding more than usual
- Increased aggression or avoidance
- Excessive grooming
- Eliminating outside the litter box
- Loss of appetite
If your cat exhibits these behaviours, check for any underlying medical conditions and consult your veterinarian. Like dogs, cats can suffer from mental health issues. While some may require pharmaceutical support, environmental stress is often a major contributor. Providing quiet spaces, interactive toys, and pheromone diffusers can help alleviate stress.
Some signs that your cat may be feeling sick:
While some stress signals overlap with illness, it’s important to recognise key symptoms of health problems in your cat:
1. Changes in Eating and Drinking Habits
- Eating Less or More: A loss of appetite may indicate dental pain, gastrointestinal issues, or kidney disease, whereas increased appetite can be linked to diabetes or hyperthyroidism.
- Drinking Excessively: Increased thirst could signal kidney disease or diabetes. Chronic kidney disease (CKD) is one of the most common ailments in senior cats, affecting approximately 30% of felines over the age of nine (González-Castillo & Sanmiguel-Plazas, 2018).
2. Unusual Urination or Defecation
- Frequent Urination: Increased visits to the litter box with little urine output may indicate a urinary tract infection (UTI/FLUTD) or even a life-threatening blockage in male cats.
- Diarrhoea or Constipation: Chronic diarrhoea may be due to food intolerance, parasites, or inflammatory bowel disease, while constipation could signal dehydration or megacolon. Many ultra-processed pet foods are not optimally designed for obligate carnivores, often leading to gut health issues. A biologically appropriate diet rich in high-quality animal protein and moisture can support digestive health and reduce gastrointestinal disturbances.
- Eliminating Outside the Litter Box: This is not just a “bad habit.” It can indicate stress, arthritis, or urinary issues.
3. Decreased Activity or Reluctance to Jump
Cats are natural climbers, jumpers, and explorers. If your normally agile cat hesitates to jump onto their favourite perch, it could be due to arthritis, joint pain, or an injury. Studies have shown that approximately 61% of cats aged six years and older have radiographic evidence of osteoarthritis, with this prevalence increasing to over 90% in cats older than 12 years. Despite these high numbers, many pet parents may not recognise the subtle signs of arthritis in their cats, often attributing decreased activity to normal ageing. In fact, one study found that only 13% of cat owners reported noticing lameness in their cats, even when radiographic evidence of osteoarthritis was present (Keller et al., 1999).
4. Sleep and Night-Time Vocalisation Changes
Cats sleep a lot (12–16 hours per day), but noticeable changes in sleep patterns can signal discomfort, stress, or cognitive dysfunction, especially in older cats. If your senior cat has suddenly taken up nocturnal pacing, loudly announcing their presence at odd hours, they may be experiencing confusion or anxiety. Excessive meowing—especially at night—can also indicate pain, stress, or cognitive decline, often leaving pet parents wondering if their feline friend has taken up opera rehearsals at 3 AM.
5. Grooming Changes
- Over-Grooming: Cats who excessively lick or chew at their fur may be stressed or suffering from skin allergies.
- Neglecting Grooming: A cat that stops grooming altogether may be unwell, arthritic, or experiencing dental pain. Feline odontoclastic resorptive lesions (FORLs) are one of the most common dental diseases in cats, affecting a significant percentage of the feline population and contributing to oral pain and eating difficulties (Lund et al., 1998).
6. Sudden Changes in Personality
You might be able to tell that your cat is sick if they become unexpectedly withdrawn, aggressive, or overly clingy. They may be in pain or experiencing emotional distress.
Common Misconceptions About Cat Health
- “If my cat is purring, they must be happy.” While purring is often associated with contentment, cats also purr when they are in pain or anxious as a form of self-soothing.
- “My cat is just getting old; slowing down is normal.” While some decrease in activity is expected, reluctance to jump, play, or groom could indicate arthritis or another medical issue.
- “If my cat stops eating, they’ll eat when they’re hungry.” Cats who stop eating for more than 24–48 hours risk developing hepatic lipidosis (fatty liver disease), a life-threatening condition.
What Should You Do If You Notice These Signs?
If you observe abnormal behaviours in your cat, consult your veterinarian promptly. Early intervention can significantly improve treatment outcomes. Diagnostic tests such as bloodwork, urinalysis, and imaging can help identify underlying conditions.
Additionally, an integrative approach, including species-appropriate nutrition, supplements, and stress-reduction techniques can support your cat’s overall well-being.
Final Thoughts
Understanding what’s normal for your cat is key to recognising when something isn’t right. Whether it’s a subtle change in appetite or a new reluctance to jump, paying close attention to these signs ensures your feline friend stays happy and healthy for years to come.
If you ever find yourself wondering, “Is my cat acting normal?” Trust your instincts and seek veterinary advice. Your cat’s health and happiness depend on it.
About the Author - Dr. Nicole Rous
Dr. Nicole Rous completed her degree with Honours from the University of Sydney in 2008. She initially worked in the UK before returning to small animal practice in Melbourne, Australia. Dr. Nicole has a keen interest in animal reproduction and has been granted Membership with the Australian and New Zealand College of Veterinary Scientists in this specialty. She is also passionate about complementary therapies such as massage and enjoys discussing ways to enhance pets' overall well-being and quality of life.
In August 2021, Dr. Nicole joined the Mont Albert Veterinary Surgery team as a director and continues to provide exceptional care to her patients. She is dedicated to utilising her knowledge and experience to assist pets in living longer, healthier, and happier lives.
Dr. Nicole's commitment to providing natural and holistic health practices for pets inspired her to establish Shy Tiger, a company that offers natural pet products made from premium ingredients sourced primarily from Australian farms and producers. Her expertise in natural health practices and dedication to providing excellent care to her patients make her a reliable partner for pet owners in Melbourne and beyond.
References
González-Castillo, L. F., & Sanmiguel-Plazas, R. A. (2018). Study of Chronic Renal Disease in Canine and Geriatric Felines. Ciencia y Agricultura, 15(2), 71–81. https://doi.org/10.19053/01228420.v15.n2.2018.8397.
Keller, G. G., Reed, A. L., Lattimer, J. C., & Corley, E. A. (1999). Hip Dysplasia: A Feline Population Study. Veterinary Radiology & Ultrasound, 40(5), 460-464. https://doi.org/10.1111/j.1740-8261.1999.tb00375.x.
Lund, E. M., Bohacek, L. K., Dahlke, J. L., King, V. L., Kramek, B. A., & Logan, E. I. (1998). Prevalence and Risk Factors for Odontoclastic Resorptive Lesions in Cats. Journal of the American Veterinary Medical Association, 212(3), 392–395. PMID: 9470050.
