Butch is an 11 year old female dog who came to see Dr Nathalie because she hadn't been eating for a few days and she had been quieter than usual. Being an older female who had not been desexed the vet was immediately suspicious of a condition called pyometra. An ultrasound was performed which confirmed this. In its simplest terms, pyometra is an infection in the uterus. However, most cases of pyometra are much more difficult to manage than a routine infection.
Infection in the lining of the uterus is established as a result of hormonal changes. Following oestrus ("heat"), progesterone levels remain elevated for 8-10 weeks and thicken the lining of the uterus in preparation for pregnancy. If pregnancy does not occur for several heat cycles, the lining continues to increase in thickness until cysts form within it. The thickened cystic lining secretes fluids that create an ideal environment in which bacteria can grow. Additionally, high progesterone levels inhibit the ability of the muscles in the wall of the uterus to contract, which means that bacteria that enter the uterus cannot be expelled.
The preferred treatment is to surgically remove the uterus and ovaries, an ovariohysterectomy or a spay. However, these dogs are quite ill so the surgery is not as routine as the same surgery in a healthy dog. Intravenous fluids are often needed before and after the surgery. Antibiotics are given for 1-2 weeks. Butch was spayed and she is now doing well after her surgery. She also had two lumps removed from her mammary glands but luckily they were sent off to the laboratory to be analysed and have come back as benign breast or mammary lumps which have been completely removed.
The reason we recommend desexing female dogs at a young age is to prevent both pyometra and mammary/breast cancers. Butch was very lucky that she has recovered from both of her problems because not all dogs with these problems do as well as her