Tight regulation was studied in humans in a famous 10-year study called the Diabetes Control and Complications Trial (DCCT)  that compared the incidence of diabetic complications between tightly regulated and traditionally regulated diabetics. The tightly-regulated patients showed:
- 76% reduced risk of eye disease
- 50% reduced risk of kidney disease
- 60% reduced risk of nerve disease
Based on these results, everyone in the control group was put on a program of tight regulation before the end of the study. Since this study, the target range for humans has been lowered significantly.
Unfortunately, no such studies have been conducted for dogs and cats, and vets continue to target glucose levels that are well above euglycemic range.
In dogs, tight regulation is especially important if the dog still has its eyesight, since blindness can ensue when blood glucose levels stay above 180mg/dL (10mmol/L) for too long. Remaining beyond the renal threshold for glucose for extended periods of time can also mean damage to the kidneys and other vital organs. 
In many dogs it is possible to achieve TR by using a high-fiber diet combined with strategically-timed shots of NPH or Lente insulins. It is also possible to manipulate feeding times to match the way the individual dog metabolizes the insulin. Most dogs are fed 2 equal portions of food 12 hours apart, and receive their insulin after eating. Some achieve optimum results with a 3 or 4 daily meals pattern, dividing the total food portion this way, with injections remaining on a 12 hour cycle.
If TR cannot be achieved this way, the dog should be switched to a basal/bolus regime, similar to that of diabetic humans. There are some dog owners that successfully combine fast or rapid acting insulin (bolus) and intermediate or long-acting insulin (basal), for example. The most common basal/bolus combination for dogs would be use of R//Neutral insulin as bolus and NPH/Isophane insulin as a basal.
Those dogs whose blood glucose levels drop lower than desired at peak time are scheduled for a snack to ensure hypoglycemia won't occur. Learning the individual pattern of highs and lows and using them to one's advantage is the key here.
- ↑ Canine Diabetes. New Hope Animal Hospital.
- ↑ Diabetes Control & Complications Trial (DCCT). National Diabetes Information Clearinghouse-NIH.
- ↑ Advantages of Controlling Type 1 Diabetes. Genetichealth.com-.
- ↑ Guidelines for Successful Diabetes Management-Page 3. Intervet.
- ↑ Caninsulin Glossary-Complications. Intervet.
- ↑ Caninsulin Glossary-Renal Threshold. Intervet.
- Beyond Insulin Therapy: Achieving Optimal Control in Diabetic Dogs Rand, Jacqueline, Fleeman, Linda, 2005, University of Queensland
- Successful intensive insulin treatment of type 1 diabetic dogs leads to restoration of peripheral leukocyte insulin signaling gene expression and enzyme activities Mori A, Lee P, Sako T, Mizutani H, Arai T., 2009, Journal of Veterinary Medical Science