Hi Glenn,
They aren't tripe companies but dog food 'wholesalers'. They sell almost everything for the raw diet. Tripe (beef, goat, lamb tripe) , chicken, turkey, buffalo, goat, lamb, deer, herring, etc. THen they will also sell the organ meats, supplements (powders, oils ), books and they even sell veggies already mixed and chopped or juiced. THe meat and veggies are sold frozen.
These companies were started by people years ago who wanted to feed raw but were having hard times locating the products etc.
FOr the most part I just buy tripe, herring and some supplements. I buy my organ meat, beef, and chicken from my butcher. I also raise my own lambs that I take in to have made into dog food. (this is WAY cheaper and it is guarented antibiotic and hormone free!
One of the companies is called Canine Choice and the other is Fresh Start (there are more companies around here as well). There are many pet food stores here that have large freezers in it and carry all these meats/veggies. This way it is very convenient and easily accessible for most anyone who feeds raw.
Again, these companies were started by a few 'people' who got together and decided to make things easier for people to feed raw. There are certain 'standards' that they have to go by etc (as one would expect). They have a 'warehouse' but most of the food is 'sold' by distributers. They deliver is right to my doorstep. Course this is a bit more expensive than doing it yourself, but for me when it comes to tripe, herring and a few meats that I don't have access to, or don't want to 'handle', it is worth it. THe larger the quantity you buy and the larger it is packaged (I buy 1200 gram bags frozen) the cheaper it is. So, for the person who wants to only buy 'small' portions it is a bit more expensive.
Generally speaking 2- 1200 gram bags of tripe mixed with some organ meat is enough to feed 5 adult gsd's a day. I will sometimes feed it without organ meat as well.
Feeding raw is not about balancing each meal but balancing quantities and amounts over a 'week' period etc. So, at times, I may feed more meat at one meal and a little less meat at another meal.
When I first switched my dogs to raw, I only fed tripe and learned within a short peroid of time that this was NOT sufficient. First off, you are not getting enough 'bone' for calcium /phosphorus. Second, it is EXTREMELY important to feed red meat as well. One should be feeding organ meats (liver, kidney, heart) at least once a week. Red meat is crucial for supplying the body with zinc. Zinc is crutial for a healthy dog! (there are other souces of zinc as well)
I generally feed my dogs 3 meals of a 'bone' meat a week. So, it might be chicken necks/backs or herring or turkey necks/backs etc. THen I will feed 2 meals of red meat 'cuttings' mixed with organ meats. This is ground together by my butcher , frozen and then cut into squares. In this mixture you have very good amounts of fat, red meat and organ meat. Then I will feed a meal of just organ meats and then 1 meal of tripe. I used to fast my dogs on one day a week but have not done this on a regular basis for the past year. There are pros and cons to fasting. Some dogs do very well and some dogs don't.
I tend to only give 1 source of protein for each meal. So, if I am feeding chicken then I might add chicken livers, gizzards, hearts etc but not any 'beef' products.
Generally speaking a dogs meal should be 2/3 meat/protein source and 1/3 veggies. So, I might give less 'meat' in a meal but then would be adding some cottage cheese, eggs etc). There really is not 'set' amount as so much depends on the individual dog, it's energy, body , and how it burns its food.
It has been suggested that dogs fed a raw diet will actually let you know how much is too much as far as food goes. They will only eat until they are full and will even leave some behind if it is too much etc. I find that true for 3 of my dogs. However, the other 2 will eat all that you put before them and more!!, so I do regulate their intakes.
I believe Ed has some good books listed on this site. There are quite a few out there etc. I have just ordered Dr. Ian Billinghursts new book but have not recieved it yet. He has 2 other ones out that I have but I have 'heard' that this 3rd book is all one would need to purchase? Another small easy to read and understand book is Kymathy Schultze's, The Ultimate Diet. I have this one as well and like it. Another good 'beginner' book that is cheap is Susan Johnson's "Switching to Raw". Very easy to read and understand.