Both the mastiff and the greyhound are very large dogs, so keeping them in a small home can make it very crowded. However, these breeds can usually live together in larger homes because they have good tempers. However, given their large sizes and high energy levels, some owners might find it a bit much to own both breeds.
Mastiffs have good tempers, according to Michigan State University. Since the mastiff is so large, its gentleness is welcomed. The greyhound enjoys the company of other dogs, according to the American Kennel Club. Greyhounds also get along well with other pets they are raised with, though they tend to chase anything small they see moving outside. The Italian greyhound definitely gets along with the mastiff and is smaller, so it does not take up as much of the mastiff's space.
Space and Exercise
Greyhounds need a lot of space, since they are very athletic dogs and need daily exercise. Since they like to run, they should be kept in a fenced-in area so they do not run too far. The mastiff does not need as much exercise, so owners can focus more on making sure the greyhound gets enough exercise. However, the mastiff still needs some exercise, which it can get from a game or a daily walk.
Greyhounds are very independent, so they require more patience to train than other breeds. The Italian greyhound is playful and very intelligent. Mastiffs are also easy to train. The mastiff can weigh between 165 and 200 lbs, Greyhounds weigh between 60 and 70 lbs. In some ways the mastiff and greyhound can be difficult to handle for owners that do not have enough energy to keep up with them. The greyhounds are energetic, so often needs an energetic owner to keep up with them. The mastiff is not as energetic, but has a lot of power, so the owner may have a difficult time managing it on a leash.
One thing that makes greyhounds and mastiffs similar is they both require very little grooming, which can save owners a lot of time. Despite being highly energetic and loving the space of the outdoors, greyhounds want bedding and warmth. The mastiff needs protection from hot outdoor weather and should be kept in air conditioning. Mastiffs and greyhounds are also ideal for the indoors since they make effective guardians, given their size.