The main idea behind nosodes is that vaccines, in combinations of 4-5 diseases all at the same time, are weakening the immune system rather than strengthening it, and the next dose being given before the immune system has had a chance to begin building immunity toward that particular virus; and nosodes DO contain the same viruses you are using in vaccines, but in smaller INDIVIDUAL doses, so your pets can build immunity to one disease at a time, and not weaken the immune system. Also, many believe injecting vaccines into our pets is the cause or an additional cause, of so many of the cancers we are seeing these days in so many pets. The rabies vaccine is required by law in many states, so that may HAVE to be given, but should NOT be given at the same time as any other vaccines. If you are using nosodes, they should be in place of the equivalent vaccine, not in addition to. Doing that just defeats the purpose. Many studies have been done that state nosodes DO IN FACT work, and other studies have been done that say they don't. Generally, the studies for either side are done by someone who has an interest in either making money from vaccines, or groups of people using nosodes and wanting to further THEIR goals. There is a ton of info out there to support both sides, depending on which side you choose to believe.
MY belief is that healthy animals, not having to fight off all of the toxins being used on or injected into most pets these days, have a much stronger immune system, and are able to fight off many of the diseases that they are exposed to. Flea/tick medicines, as well as heartworm preventatives, are all toxins, which in turn make our pets toxic, in order to kill off the parasites we are seeking to prevent. Healthy immune systems, in healthy pets, make those pets less appetizing to parasites- for example, if you have 3- 8 week old puppies- one who is totally healthy and eating a top of the line food, one who is borderline healthy, eating a medium quality food, and one who is thin and not healthy who is eating grocery store food, and you introduce fleas... you might find a few fleas on the first puppy, more on the second puppy, but most all of them on the third puppy, who is also likely to become dehydrated from all those fleas draining its blood supply and possibly even die from the 'attack' before you have a chance to get him/her built back up. So, in the long run, if you start with a healthy baby, use high quality food, and eliminate all the toxins, you will have a headstart in keeping them healthy no matter what they are exposed to. Nosodes alone will not necessarily save a life, if the pup is taking in toxins from other things, and poor quality food. In combination with the best of everything, you have a much higher chance of that puppy fighting off diseases and parasites BECAUSE s/he is already healthy to begin with. Nosodes are tiny quantities of each of the diseases, given in a killed form, at the proper times, to help the puppy build immunities to that particular disease WHILE healthy, with NO chance of contracting that disease as they are with vaccines (vaccines CAN cause the pup to come down with the virus they are being vaccinated for, though it is a small chance).
I honestly know NOTHING about bullmastiffs or those who breed them, so I cannot give you any thoughts on that. My guys are English mastiffs, from a top breeder. I can ask my breeder if she knows anything about them, and see what she suggests, if you'd like. Being that she is very much involved in the dogshow scene, she may even know many of the bullmastiff breeders, and be able to tell you who is best. Her website has a TON of info on the holistic side of puppy raising, and she is an expert on feeding/nutrition of dogs. PM me for the link, if you want it.