Ideally, dogs should be taken to council-designated areas where they can be safely let off the leash to run free. It is important to use these specifically designated areas not only to ensure their own safety (preventing the risk of being hit by a car) but also the safety of farm livestock and wildlife which can be threatened by a dog let loose in their habitat.
Vomiting is not a disease or disorder in itself; it is a clinical sign of some type of digestive disturbance or as a result of another disease or disorder. Occasional bouts of vomiting can be considered normal but if the vomiting persists and is accompanied by severe or bloody diarrhoea, lethargy, weakness, depression, pain or fever then this is a sign that something is seriously wrong and veterinary attention is required. Vomiting can be caused by something the dog has eaten (e.g. rotten food), ingestion of toxins, adverse reactions to drugs or an allergic reaction to something in the environment.
However, if you decide to keep your dog outdoors, it is important to consider how you'll ensure it receives the appropriate amount of human contact (particularly during those cold winter months in which we'd all much rather stay snuggled inside rather than playing fetch with our pals in the cold!). An option could be to enlist the service of a dog walker. Also, if you work long hours or are sometimes forced to take overnight trips, it may be useful to consider "doggy day care" facilities to ensure that your dog receives the TLC and companionship it will need in your absence.
Puppy Roundworms can infect humans. To prevent this infection, puppies should be wormed regularly throughout their first year of life, and owners should be thorough with their own personal hygiene after having interacted with the dog. Tapeworms, Hookworms, and Whipworms can also infect dogs, and your veterinary surgeon can advise when to worm the dog.