Lump on My Dog or Cat: When to Worry and When It's Harmless

Take a breath. Not every lump is cancer. In fact, the majority of lumps found on dogs are benign. But every lump deserves attention. The key is knowing which ones can wait for a regular vet appointment and which ones need urgent care.

When you find a lump, note these things: - Location: Where on the body? - Size: How big? (Compare to a pea, marble, golf ball) - Texture: Soft and squishy? Hard and firm? Smooth or irregular? - Mobility: Does it move freely under the skin, or is it fixed to underlying tissue? - Growth rate: Is it new, or has it been there a while? Is it growing? - Pain: Does your pet react when you touch it? - Skin surface: Is the skin over it normal, red, ulcerated, or hair-free?

Soft, round, moveable lumps under the skin. Very common in older and overweight dogs, especially Labradors. They are harmless fat deposits. Usually left alone unless they grow very large or restrict movement.

Small, round bumps that sometimes have a white or cheesy discharge. Caused by blocked oil glands. Common on older dogs. Usually harmless but can become infected.

Small, pink, button-like growths that appear suddenly — usually on young dogs under 3 years. They look alarming but almost always resolve on their own within 2-3 months.

Hot, painful, swollen lumps usually caused by bite wounds or infected scratches. Common in cats that go outdoors and fight. An abscess needs to be drained and treated with antibiotics.

Small, cauliflower-like growths. Common in puppies and older dogs with weakened immune systems. Usually harmless and resolve on their own.

The most common malignant skin tumour in dogs. Can look like almost anything — a small bump, a large mass, or even a mosquito bite. They change size rapidly (can swell and shrink) because they release histamine. Any lump that changes size unpredictably should be checked.

Common in unspayed female dogs and cats. Approximately 50% of mammary tumours in dogs are malignant, and about 85% in cats. Any lump near the nipple or mammary chain needs a vet visit within days.

Any lump that doubles in size within weeks needs immediate attention, regardless of what it looks like.

A lump with broken skin on top, bleeding, or oozing, is concerning. Malignant tumours often outgrow their blood supply and ulcerate.

See a vet within a few days for: - Any new lump you have not had checked before - A lump that is growing - A lump that is hard, fixed, or irregular - A lump that is ulcerated or bleeding - Multiple new lumps appearing

- Fine needle aspirate (FNA): A quick, usually painless procedure where the vet inserts a small needle into the lump and examines the cells under a microscope. This tells you whether the lump is benign or suspicious. - Biopsy: If the FNA is inconclusive, a small tissue sample is sent to a lab. - X-rays or ultrasound: To check if the lump extends deeper or if there are internal masses.

If your vet says a lump is benign and can be watched, measure it monthly. Place a coin or ruler next to the lump and take a photo. Compare over time. Omelo makes this easy — log each measurement with a photo, and if anything changes, you have the complete history ready for your vet.