Can you take a dog to handball training?
Yes you can defiantly take your dog to the training but you need some confinement solution because most probably h'll be chasing the ball and won't let you practice.
Dogs get super excited when a ball is in the air so you can't really have a normal training session while your dog is running lose.
So is the leash a good idea and will it be enough to hold the dog or could it be dangerous to your hyper dog?
I personally think that the leash can not do the job especially that dogs get super excited and he'll keep jumping and risk strangling himself.
What is the solution then? I would suggest using a crate, to keep him safe and close enough from you, I know crate training dogs is a hard job but when it's done you can take your dog anywhere, checkout this crate training website for some tips.
Can you take a cat to handball training?
Cats are even worst than dogs and will not hold still any where and they react even worst to the leash so how can you take your cat to training.
I would suggest you don't take you cat to training since cats are not very interested in seeing you all day long and won't get very excited about the ball but if left alone with too many people around they might react badly.
Can you take a rodent to handball training?
I would be very careful about taking a rodent to training especially if there are girls in there, some people aren't used to pet rodents and may react badly.
However, they would not mind being in the field if you give them something to gnaw on you can checkout this pet rodents website for more information.
Conclusion
Can you take your pets to handball training? yes you can if you can provide a good confinement option for them so you can enjoy training and your best friend's company.