dsb said:
Please tell me how to test "at home." Vet increased dose from 4 units to 5 units after a few months. He IS a rather large cat.
The maximum starting dose for Lantus is 2u--and that's for VERY large cats. Most cats only need around 1u if they're on a low carb canned, diet. Also, dose increases for Lantus need to be made in .25u to .5u increments, not in whole units. Often vet test numbers are inflated from stress and leads to dangerous overdosing, which is why testing at home is the only way to safely administer insulin and determine your cat's correct dose. Unfortunately, sometimes vets are not aware of all of the aspects of current recommended treatment of feline diabetes.
Home testing seems daunting at first, but after about a week people are amazed how easy it is and how much their cat cooperates. You can get an inexpensive human meter and strips at Walmart or the drug store, and you will save a ton of money because you will no longer have to bring your cat in to be tested at the vet.
Not only that, but testing before each shot prevents deadly hypoglycemic incidents. Studies have shown that with the combination of home testing, Lantus, and a low carb canned diet, newly diagnosed cats have an 80+% chance of going into remission. I've attached an article that I would strongly urge you print out and give to your vet so that he can get on track with the right treatment for your cat.
In the meantime, though, there are a ton of very experienced and helpful people here that can help you get your cat regulated, so that he can get better. As Jennifer mentioned, you may also want to have him checked out for a UTI, since they are very common in uncontrolled diabetics. Once his diabetes is under control, the urinating should stop. There is a wealth of knowledge here--we can help you learn to home test, find the right food, and adjust doses properly so that your kitty can get better.