Roughly one in four dogs and one in five cats will develop cancer in their lifetime. Many of these cancers are highly treatable when caught early. Many are missed for months because the early signs are easy to dismiss.
The monthly lump check
Once a month, run your hands slowly over your pet's body. Armpits, groin, neck, belly, behind the ears, under the jaw. You're feeling for anything new — a lump, a thickening, an area of swelling. Mark them on a notebook with a sketch. A lump that's growing, hard, attached to underlying tissue, or ulcerated should be aspirated by a vet within days, not weeks.
Unexplained weight loss
If your pet's food intake hasn't changed but they're losing weight, that's a red flag. Tumours consume calories. Bring it up at the next vet visit and ask for bloodwork plus an abdominal ultrasound.
Wounds that don't heal
A scratch or sore that hasn't closed in two weeks is worth a biopsy. Mast cell tumours often look like benign bumps. Squamous cell carcinoma in cats often appears as a non-healing ulcer on the nose or ear.
Behaviour changes
Hiding, reluctance to exercise, sudden lameness, loss of interest in food they used to love. Cats are particularly stoic — a cat who is "just slowing down" may be in significant pain. Trust the change. The internet will tell you it's "just age." The bloodwork will tell you the truth.
Cancers worth knowing by name
Lymphoma is the most common cancer in dogs and cats. It often presents as enlarged lymph nodes — feel under the jaw and behind the knees. Hemangiosarcoma in dogs is silent until rupture; collapse and pale gums in a middle-aged Golden Retriever or Labrador is hemangiosarcoma until proven otherwise. Mammary tumours in unspayed female dogs are about 50% malignant — early spaying before the first heat reduces lifetime risk by 95 per cent.
Modern treatment is gentler than people think
Chemotherapy in pets uses much lower doses than in humans. Most dogs and cats lose no fur, eat normally, and play normally during treatment. The goal is good months and years, not survival at any cost.
