highly recommend for athritis
My 10 year old 100lb lab was limping every day due to hip arthritis. My vet recommended this as an alternative to daily oral arthritis and pain medication. I bought the first box from him and the key issue is that it does not have to go in the muscle to be effective. You simply grab them by the scruff of the neck and inject in under the skin. Yes, you have to buy your own syringes with needles, but different dogs will most likely need a different size needle. I use a 3cc with a 21guage 1 1/2inch needle. I would use at least a 1 inch needle. It appears to cause him little or no discomfort, as opposed to an IM injection.
As I recall, we started with twice a week for 3 weeks. We noticed a big improvement after 2 weeks. We then tried to space it out to the recommended once monthly, but noticed he was limping around 2-3 weeks. We settled on an every 2 week schedule, sometimes a little longer. He can walk a mile at the dog park every day with no limping. Sometimes he even runs a little bit, though we discourage it. I get 2 doses from each bottle or 4 per box, so I am buying a box every 2 months. Obviously your vet will advise you on the correct dose, but that gives you an idea of the cost. I was surprised how effective it is, especially since it is apparently a form of glucosamine. I was also surprised how quickly it worked. It is possible your dog may require less frequent dosing, but that is what works for us and the difference is remarkable.