Some experiences from living with our dogs:
Problems between male dogs: "that's because he's castrated"
Should male dogs be overly interested in your castrated male dog, especially his "private parts", please don't just put it down to you dog being castrated and, therefore, being allegedly too "female". Actually, this is rarely the case!
Please have your dog checked thoroughly by a vet, especially, if not mainly, his urine and faeces. This over-interest by other males can be due to bladder infections / bladder or kidney crystals/stones and/or other "enticing" smells in region of the private parts, e.g. diabetes or anal gland problems!
What goes inside...
If your dog often has quite "soft" faeces and/or shows strange behaviours, please try a different food / feeding regime, especially if your vet hasn't found any physical reasons.
Dicker for example does not get on with dry food (and I have tried!). He loses weight, however much he is fed, suffers with painful bloating, has too soft and too much stool and also gets hyperactive (as you can appreciate, that's no joke with an energetic Springer!).
Since we took to cooking for him ourselves based on a recipe made up by the animal nutrition department of the Veterinary University of Hannover, Germany, his activity level is normal again for healthy Springer Spaniel.
Baine is fed fresh, raw food which we buy frozen from AMP prize choice, where we also get the ingredients for Dicker's food.
Dogs can suffer allergies and food intolerances as well. It can make a huge different to their (and your!) quality of life if they are fed with the food they can tolerate. They are as much individuals humans are!