...it’s not the case that one person’s ‘needs and safety’ comes above the neighbour’s right to let their dog out, in a shared garden, that they also pay for, as long as they are doing so within the rules of the lease or any relevant rules.
Needs and safety of people do in fact trump anyone's whim about their pet. This is because dogs are not humans and do not have the rights that people have. Dogs are not extensions of their owner's personalities. They are property. So are homes and gardens. The OP has a right to the enjoyment of her property. The neighbour has a right to enjoyment of his dog but not to let the dog negatively affect the OP's enjoyment of her property. The neighbour has the right to enjoy the property he pays rent for, but not to allow his other property, the dog, to create a nuisance or interfere with the OP's enjoyment of the property.
A dog can't bark all night in a flat and can't monopolise a shared space by its presence or the presence of urine or fecal waste, any more than any other property of a resident can monopolise a shared space. Dog waste, which is hazardous to humans just as human waste is, isn't something everyone else has to tolerate 'because dog'. A dog in this case is no different from a rusty old junked car that the neighbour parks in the garden and tinkers with as a hobby.
Dogs are not some special class of property that is immune from all considerations of human needs, rights, and safety. They can be and are frequently considered a nuisance. A substantial interference with enjoyment of a shared space is considered a nuisance (such as creating noxious odours, attracting flies or rats which feed on feces, or loud and constant barking or aggressive behaviour) if we are to get all legal about it.
@Dotty07
You should consult your own deed as there may be T&Cs there that would apply to you if you were to choose to keep a pet, including a dog. The other units should be bound by the same T&Cs if there are any in the deed regarding pets and use of the common areas, and an owner who rents out a unit can't do that without incorporating terms and conditions in their deed in any tenant lease. You should contact the landlord and ask if the terms of the neighbour's lease include keeping a dog, and if so, under what terms and conditions. You could also ask the LL to have a stern word with the tenant.
It's a pity when a resident feels there is no recourse except to the law, but if there is a local authority or city dog warden or environmental health department for your area then that is the avenue to go down if contact with the landlord proves fruitless. The LA has an interest in maintaining public health and safety and hence its role in matters involving dogs.