Mammary gland tumours in female dogs
DOGS can develop mammary or breast tumours which can either be benign or malignant. Benign tumours are generally slower growing and less likely to spread to other areas of the body. Malignant tumours tend to be faster growing and can spread through the lymphatic system to other areas of the body. The tumours usually affect older female entire dogs - they are extremely rare in bitches that have been desexed at a young age before they have had an oestrus cycle. The statistics for developing tumours have been found to be 0.5 per cent for bitches spayed before the first oestrus cycle, 8.0 per cent for bitches spayed before the second oestrus cycle, and 26 per cent for bitches spayed after the second oestrus cycle. Once the bitch is over 2.5 years old, there is no benefit to be gained by spaying to prevent mammary tumours, although there are plenty of other reasons for spaying older female dogs. The signs of mammary tumours can be single or multiple masses that grow in the mammary tissue along the dogs abdomen. The tumours can behave in different ways, they may be slow growing but sometimes they grow very quickly and can become ulcerated. If you suspect your dog has mammary tumours it is important to take them to the vet and have the lumps checked. Most mammary lumps can be surgically removed. Surgery can be quite successful if the lumps are benign, however if they are malignant the dog may not do well long term. If the lumps are removed, they can be sent to the laboratory to find out what type of cancer they are and whether they are likely to spread or not.