Desexing

[jacqui835]

Physically for a large dog yes. In respect to temperament, my sister had a male she desexed at about 18 months, and he has since changed completely. He has put on a lot of weight and doesn't have the same drive (ie doesn't go with her partner for bike rides anymore), but he also has better recall and doesn't try to escape all the time anymore.

Personally I think the notion that desexing causes weight gain is a myth.

I think what often happens is the desexing coincides with the end of growth and the slowing of a dog's metabolism at maturity. Owners fail to adjust food intake and voila - fat dogs!

I bet once slimmed down, your sisters dog would have more energy.

Maybe but he used to be so keen to go on walks and loved playing games, whereas now he wants to go home once he reaches the end of the street. They waited till 18 months so as a papillon, he was well and truly done growing. He used to be very lean and loved accompanying her partner on his long bike rides, but now well, he likes to sleep and eat. On the plus side though, he also used to be an escape artist and had 0 recall (to be fair they did no training though), but now he doesn't leave even with the gate open and recall is not an issue. Maybe he was always going to be like that as an adult, but they feel like they've owned 2 different dogs and the change just happened to occur within 6-8 weeks of being desexed. I think perhaps he had a strong urge to reproduce, and that was what drove him, and once removed there just wasn't a whole lot left. Kinda like humans, maybe some dogs are more 'frisky' than others.

I knew a german shepherd though that was desexed at 8 months, and a year later, he still had all the same problems. Still wants to fight, hump/dominate other dogs and still doesn't listen to his owner.

Desexing seems to reduce the amount of food a dog needs (both directly in terms of reduced muscle mass and thyroid action and indirectly through less drive/desire to explore), and this combined with the end of the growth period can lead to fast weight gain.

Guess it depends on the dog.

[Steve]

Is it a myth that dogs get fat easier when they are desexed? The science seems to suggest they do.

Saying that owners cause dogs to be fat post desexing isn’t really the whole story. Ovaries produce estrogen, and if you take that away from a mammal the body looks for other places to get needed estrogen from. Fat cells can produce estrogen, so when the estrogen goes the body works harder to convert calories into fat to increase estrogen levels. Fat cells don't burn calories the way muscle cells do, which causes the weight gain

Testosterone helps the body to create lean muscle mass out of the calories that are taken in. Muscle cells burn more calories than fat cells do, increasing the metabolism. When levels of testosterone drop it results in the loss of this muscle. This means a lower metabolism. The lower the metabolism is, the slower the body burns calories, which causes weight gain.

If you start to lower the food intake when you notice a bit of weight gain then the body can go into “famine effect” and these stress hormones signal the body to hang onto all the food that comes in – in case the body doesn’t get enough food for a long time so it starts to store calories.

Fact is an extra weight gain may even lessen the results of these hormones not being present and help to protect against bone diseases, incontinence etc so don’t be too hard on yourself if your dogs put on a bit of extra weight when they are desexed. You don’t want fat dogs but it might be in their best interests to have them a bit meatier post op that they were pre op.

If these hormones decrease naturally the body prepares for it and the results are not as obvious but when they are taken away in a young animal there is definitely stuff going on inside the dog which the owners have no idea of.