Health
A pea-sized lump near the back teats that does not seem to bother her. The smaller it is when it reaches the vet, the better her outlook.
Caution. A lump growing week by week, skin that has broken open or is bleeding, a red, hot, painful area along the mammary chain, or coughing and laboured breathing in a bitch with a lump: call your own vet today. Any new lump should be seen within days.
Do not look for the answer in a Facebook group, on TikTok or on a forum. Look for someone trained for this: your dog's own veterinarian, the only person who can examine, investigate and treat them.
Use this page to know what to observe, what to note and what to ask at the appointment, not to treat at home. If you still have doubts after a consultation, ask another vet or a specialist (dermatologist, internist) for a second opinion, not a group. And if you do not have a regular vet yet, find one now, while your dog is healthy: how to choose a veterinary clinic.
She is lying on her back on the sofa, letting you rub her belly, and your fingers find something firm, the size of a pea, next to one of the back teats. It does not hurt her and she does not flinch. It may have been there for weeks before you noticed. Or you have a ten-year-old entire bitch and at her last check-up the vet said "let's keep an eye on that lump". The first reaction is fear; the second is the temptation to wait. This page explains why you should not wait, what to note, and what happens at your own vet's, from the first appointment to the lab result that tells you what the lump is.
Mammary tumours are among the most common tumours in unspayed bitches and in those spayed late. Roughly half are benign and half malignant, with the split varying from one study to the next. You cannot tell which is which from the outside, and neither can your vet without examining the tissue. So you act early, while the lump is still small.
Any new lump near the mammary glands should be seen within days, not at next year's booster. Call today if:
A bitch usually has five pairs of mammary glands in two rows, running from the armpit to the groin. Tumours turn up most often in the back pairs, which are also the largest, but they can appear anywhere along the chain.
Pick a moment after a walk when she is relaxed and lay her on her side. With your fingers flat, work slowly along each row of glands from front to back, then over the tissue between them, up towards the armpit and onto the inside of the thigh. Feel with the pads of your fingers, not the tips. Roll her over and do the other side. Two minutes a month; the first day of each month works well.
The glands and the tissue around them are soft and move slightly under your fingers. A lump feels firmer, like a grain of rice, a pea or a hazelnut, sometimes stuck to the skin, sometimes sliding freely beneath it.
Take a photo with a ruler next to the lump. At the next appointment, a photo from two weeks earlier tells the vet more than any description.
| What you find | What it might be | How it differs |
|---|---|---|
| Small, firm, mobile lump | A benign or malignant tumour, still small | Only tissue testing can tell |
| Fast-growing lump attached to the skin | A tumour, more often malignant | Grows from one month to the next |
| Swollen glands with milk 6–10 weeks after a season | False pregnancy | Both rows, symmetrical, no distinct lump |
| Red, hot, painful gland in a nursing bitch | Mastitis (infection) | Fever, pain, after whelping |
| Large red, hot, painful area with no pregnancy or nursing | Inflammatory carcinoma | Very painful, spreads quickly |
| Soft, mobile lump under the skin | Lipoma (fatty tumour) | Confirmed by a needle sample |
The table is not a diagnosis. It shows you why your vet cannot stop at feeling the lump either.
Size matters a great deal. Tumours removed while under three centimetres have, on average, a far better outlook than large ones. That is why we keep saying it: today's small lump is not something to "monitor" for months.
The hormones of each season raise the risk of mammary tumours. The classic studies found that spaying before the first season, or between the first and second, cuts the risk sharply, and the protection shrinks with every cycle and has nearly gone by about two and a half years of age. More recent research questions how solid those old figures are and weighs the tumour risk against other effects of neutering, which vary by breed and size. Work out the right timing for your dog with your own vet, calmly, well before any lump appears.
Males can get mammary tumours too, very rarely. A lump next to a male dog's nipple still goes to the vet.
The monthly check takes two minutes. We tie it to something we do anyway, like the first-of-the-month brush, and that way it does not get forgotten.
What dog owners search for most often on the internet about this problem, with the short answer. The answers are a guide only: the decision belongs to your dog's own vet, after an examination.
No. About half of mammary tumours in bitches are benign, and other lumps can be false-pregnancy swelling, mastitis or fat. From the outside, though, you cannot tell what it is, and your vet cannot either just by feeling it. Any new lump gets checked promptly, and the firm diagnosis comes from testing the tissue once it is removed.
Once a month, lay her on her side and run the pads of your fingers along each row of glands from the armpit to the groin, and over the tissue in between. Then roll her over and repeat. The glands are soft; a lump feels firmer, like a grain of rice or a pea. Note where it is and how big.
It lowers the risk considerably if done early, before the first season or between the first and second, and the protection shrinks with every cycle. More recent studies question how accurate the old figures are and look at other effects of neutering, which differ by breed and size. Decide the timing with your own vet.
Age alone is no reason not to operate. Beforehand, your vet runs blood tests and chest X-rays to see how she will cope with the anaesthetic and whether the tumour has spread. If the lungs are clear and the bloods are good, surgery is usually still the best option, even for an older bitch.
No, that is a myth. The fine-needle aspirate and the surgery are how your vet finds out what the lump is and gets it out. The real danger comes from waiting: a malignant tumour left to grow is more likely to reach the lymph nodes and the lungs.
The information on this page is educational and does not replace an examination. For full details and a diagnosis, consult your dog's own veterinarian.
They often come together: the same causes, plans that complement each other.
Something soft under the skin, a pink button on the eyelid, a swelling that has grown since Easter. You cannot identify any of them by touch. The needle can.
The neighbour says before her first season, the breeder says in a year. The right timing depends on the dog, and recovery has clear rules worth knowing in advance.
Two months after her season she is nesting in the wardrobe, mothering soft toys and making milk. It is a false pregnancy and it usually passes. A few signs will not wait.
Drops of blood on the floor, male dogs at the gate, a restless bitch. The season itself is normal; the two months that follow are what you need to watch.
We work with your dog's behaviour, not its health. For any sign described here, book an appointment with your own vet; the related services page explains how to choose a clinic.