Every dog is different and every vet will give a different answer. Personally, I do not think dogs should be neutered until fully grown (18 months-2 years) or else their growth is stunted and they do not develop properly as male dogs.
Of course, if your dog is a pet and is causing problems, you will have to discuss the pros and cons with your vet.
6 months
Most vets can tell a pretty close guess. Some will for free.
Ask the vet.
6 months
7 months
The best age to get a pug is when the dog is a baby so the dog can know you better.Rather than going to the pet store and getting a pug at the age of 5 or 6 because the dog wouldn't really know you.
4-7months.
2 years old
Yes u should
I should imagine so, but it is advisable to get a veterinarian to neuter the cat.
Not by the owner. At that age it's a job for a veterinarian. It should have been done at 2 weeks.
6 months