I would just like to know how save it will be to neuter an 11 year old female Fox terrier? She is in very good health currently.
We just lost our 15 year old Doberman pincher to Pyometra, as she was to old to undergo the operation. And if I can prevent this now, I will, but I need to know she will be okay.
The short answer is that it depends on the health of your Fox Terrier.
The most dangerous part of most elective surgeries such as a spay or castration is the anesthesia. If you want to go by the numbers, one study reports the risk of death at 0.05 to 0.1% for healthy dogs and 1-2% for sick dogs and (https://www.dispomed.com/risk-factors-in-small-animal-anesthesia/). The risk of pyometra is approximately 2% of which have a 3% mortality rate according to this study: https://www.ncbi.nlm.nih.gov/pubmed/24114733
So, while you did have a dog that died from pyometra, it is a rare case (roughly 1/6000 according to the studies)
If you do decide to proceed with the surgery, I would recommend that you just make sure you have a full health exam with a blood and urine profile to ensure your Fox Terrier has properly functioning organs.