I agree with you 100% on the early altering. A person I know who also has a Dane had 2 vets push for her to spay her at 5 months of age. Surprisingly to me one of the vets was the vet I use and he never was pushy with me getting Addie spayed and she was 4 before I did it, and Tad my Chi was about 9 months and he didn't push me to do him earlier either. I think because I am very definite in my opinions he didn't bother to try and push it knowing that I would do it if and when I decided to. It does disappoint me to find out what he really believes as far as the age to alter and that he pushed spaying on this other person. I thought he was more aware of the current evidence that is available and certainly would not think 5months was the age for a giant breed.
I do agree with the idea that different breeds may need to be spayed at different times. One thing you are overlooking is the fact that the size of the dog is somethign that HAS to be considered. Spaying a 1 lb toy poodle isn't fun at all because everything is microsized. The same holds true for Giant breeds. At some point, depending on the equipmetn of the veterinary hospital, you move away from "standardized" dog and cat spay packs into "large animal" instruments with abdominal exploratory surgeries (ie Spays) in giant breed dogs. I've tried to spay a st. bernard on a fixed height table. The surgery took twice to three times as long (just over an hour and a half vs my usual time of 30-45 minutes) because I simply couldn't see into the dogs body cavity and I had to keep stepping away from the surgery to relieve my own back spasms.
Its a bit of a selfish route, but I know for a fact that there are veterinarians out there who flat out recommend doing each and every say so the dog is between 20 and 45 lbs for their own physical reasons. Some of them will tell owners (my old boss told owners he didn't like doing dogs over 65 lbs because he had had a bad back injury and picking up the heavier dogs was very difficult for him).
Sure there are lift tables and what not, but lets face the economics of a veterinary practice. A $6000 lift table for 8 -10 surgeries a year doesnt' make much sense.
I'm also not advocating what these veterinarians are doing is right, I'm just saying its something to think about.
Now I have known people who have had bitches get pyometra that then had to have surgery. It does happen, and recently I heard of a bitch who died but that blame should be on the vet that put off the surgery. It is treatable (by spaying) but then you have the cost of surgery and aftercare.
My experiences with pyometra as a veterinarian have not been good. If the pyo is open--meaning the cervix is open and the pus from the uterus is draining out, the dogs have a much better chance then if they have a closed pyo. Closed pyos are NOT a simple spay surgery. I've done a couple of them that honestly, I'll be quite happy to never do anything remotely close to that type of surgery ever again (the uterus popped in one boxer right as we were pulling it out, spraying me, the primary surgeon, the tech, the dog, her body cavity, and the curtains in the operating room with nice nasty fetid dog uterus goo. It was all I could do to keep from puking in my surgical mask, and then we had to work frantically to flush the abdomen back out). Its a critical situation that literally scares the hell out of some veterinarians because of the percieved risk of death to the dog.
There are risks to altering or not altering. If a responsible person chooses not to alter I have no problem with it and believe it is a personal choice. I do think people are not given all the information and sometimes misinformation in regards to altering and are pushed to alter too early.
I don't disagree with this. I think its an argument both sides are tightly mired in. You absolutely HAVE to consider both sides of the argument. Generally both sides won't bother to do that.
Now one thing to toss out there, in the wild I don't believe the females in the pack come into heat 2 times a year like most domesticated dogs do. I think only the alpha female does. That would mean our female dogs bodies are subjected to a stress that wild bitches are not. Something to consider when saying it is natural to leave them intact, we have altered that with our domestication. I don't have any references on hand that prove this as a fact, and frankly I am not going to look for them any time soon, but I recall at one point I did have information regarding that.
Youve got to look at wolves only to really be accurate. Wolves, Canis lupus, generally ony breed with the dominate male and female. Occasionally here is breding of subordinates, but not commonly. I honestly have to look up themechanisms involved with this, I can't remember right now if its a silent heat, no heat, or exactly what happens with the subordinates.
The thing is anyway you look at it, wolves breed once per year in the winter. The dominate female breeds virtually every heat cycle. Domestic dogs don't. in my mind that significantly increases the risk of complications from not breeding.