What Are the Signs of Cancer in Cats?

Cancer in cats can be a worrying possibility, but understanding the signs and knowing what to do can make a significant difference. Cats are skilled at hiding discomfort, which often makes it challenging to detect health issues, including cancer, until they are advanced. Recognising the symptoms early is key to seeking prompt veterinary care and improving outcomes.

Below, we will outline the most common signs of cancer in cats, discuss possible non-cancerous conditions that could cause similar symptoms, and explain what steps to take if you notice them.

Signs of Cancer in Cats

Cancer can present in various ways, depending on its type and location. Here are some of the most common warning signs that may indicate cancer in cats, along with other potential causes:

1. Lumps or Bumps
Any new growths or swellings, particularly those that persist or grow over time, should be checked by a vet. While not all lumps are cancerous, malignant tumours can feel firm, irregular, or fixed to surrounding tissues. Non-cancerous conditions, such as abscesses or cysts, can also cause lumps, making veterinary evaluation crucial.

2. Unexplained Weight Loss
Significant weight loss, particularly when your cat’s appetite hasn’t changed, is a common symptom of cancer. Gastrointestinal lymphoma or other cancers may prevent proper nutrient absorption. However, weight loss can also result from hyperthyroidism, chronic kidney disease, or diabetes.

3. Changes in Appetite
A reduced or complete loss of appetite may signal cancer, particularly in the mouth, throat, or digestive system. Conversely, an increase in appetite is rare but could occur with certain cancers that affect metabolism, such as insulinoma. Appetite changes can also result from dental disease, stress, or infections.

4. Sores That Don’t Heal
Persistent sores or wounds that fail to heal can be a sign of skin cancer, such as squamous cell carcinoma. These sores may bleed or become infected, making early intervention essential. Other possible causes include trauma or fungal infections.

5. Difficulty Breathing, Eating, or Swallowing
Breathing problems, such as wheezing or laboured breaths, may indicate tumours in the lungs or chest cavity. Trouble eating or swallowing, often accompanied by drooling or discomfort, could suggest oral cancers. Non-cancerous conditions such as respiratory infections or dental disease can also cause these symptoms.

6. Vomiting or Diarrhoea
Frequent vomiting or diarrhoea, along with changes in bowel habits, may point to cancers of the digestive system. Blood in the stool or vomit is particularly concerning and requires immediate veterinary attention. However, these signs can also occur with parasitic infections, inflammatory bowel disease, or dietary intolerance.

7. Swollen Abdomen
A bloated or distended abdomen may indicate tumours or fluid build-up associated with cancer. This symptom can also occur with heart disease, liver disease, or severe infections such as feline infectious peritonitis (FIP).

8. Lethargy and Weakness
Unusual tiredness, reluctance to play, or lack of energy can signal systemic illnesses, including cancer. Advanced cancer can also cause weakness and reduced mobility. Non-cancerous causes can include anaemia, infections, or metabolic conditions.

9. Behavioural Changes
Cats with cancer may withdraw from social interaction, hide more frequently, or become irritable due to pain. Conversely, some cats may seek extra comfort and attention. These changes can also occur with chronic pain or stress.

10. Persistent Bad Breath
Strong-smelling breath is often linked to dental disease but can also be a symptom of oral cancers. If your cat’s breath odour worsens despite good oral care, it’s worth investigating further.

11. Bleeding or Unusual Discharge
Unexplained bleeding from the mouth, nose, rectum, or other areas may indicate internal or external tumours. Unusual discharge from the eyes or ears should also be examined, though infections and foreign bodies can cause similar signs.

12. Limping or Mobility Issues
Bone cancer, such as osteosarcoma, can cause limping, reluctance to jump, or pain in the limbs. Arthritis, injuries, or soft tissue strains are more common non-cancerous causes of these symptoms. 

13. Changes in Skin or Coat
Skin cancers can lead to changes in colour, texture, or appearance. Lesions, rashes, or hair loss may also indicate infections, allergies, or hormonal imbalances.

What to Do Next

If you notice one or more of these signs, follow these steps to ensure your cat receives the best care:

1. Book a Veterinary Appointment
   Contact your veterinarian promptly to schedule an examination. Be prepared to describe the symptoms you’ve observed, when they began, and whether they’ve worsened. Early detection of cancer or other illnesses can significantly improve outcomes.
2. Prepare for Diagnostic Testing
   Your vet may recommend diagnostic tests such as blood work, X-rays, ultrasounds, or a biopsy. These tests are essential for confirming a diagnosis and distinguishing cancer from other conditions.
3. Discuss Next Steps
   If cancer is diagnosed, your veterinarian will explain treatment options based on the type and location of the tumour. These may include surgery, chemotherapy, or palliative care to manage symptoms and improve quality of life.
4. Monitor Closely
   If cancer is not diagnosed but symptoms persist, follow up with your vet. Some cancers mimic other illnesses, so ongoing vigilance is crucial. Keep a record of any changes in your cat’s condition and report them promptly.
5. Consider a Referral to a Specialist
   For complex or advanced cases, your vet may refer you to a veterinary oncologist. These specialists can offer advanced treatment options and tailored care. 

Conclusion

Cancer in cats is challenging to detect due to their natural ability to hide discomfort. Recognising the signs early and seeking prompt veterinary care can make all the difference. While many of the symptoms listed above can also indicate non-cancerous conditions, they should always be investigated by a veterinarian.

Timely action is essential for your cat’s health and wellbeing. Early detection improves treatment outcomes and gives you peace of mind knowing you’ve done everything possible for your furry companion.