The more medical term for after eating, after a meal. In humans and dogs, food begins to pass through the system starting at about two hours after eating. The system also begins turning it into glucose at this point. If a human diabetic using insulin finds his or her blood glucose levels are still too high after eating, he or she may use more rapid/fast-acting or short-acting insulin as a corrective measure to lower the blood glucose levels.
Humans with both types of diabetes check their blood glucose levels starting here to see how much their meal has made their bg's rise. If they are using analog or R/neutral fast/rapid-acting insulins as a bolus dose to cover their meals, that insulin has already started working, since they use it either shortly before or shortly after a meal.
As a rule, we don't give our pets insulin before they eat because it's not safe to do it. If the pet doesn't eat its meal, you will be dealing with hypoglycemia (hypo), because the dose of insulin you have given was also meant to cover the uneaten food.
Food spikes sometimes have visible symptoms in dogs--panting after meals. The panting is a sign that the food has begun to be digested and that the food and insulin are not a "match". When the food "beats" the insulin, blood glucose levels are on the rise. This means that the insulin has not begun working hard enough to handle the rising bg's or that the insulin given was not enough to handle the bg rise. It can also be a matter of timing regarding the insulin and food. In this case, giving insulin a bit earlier or later than the usual post-meal can help. Never make these kind of adjustments without first consulting your pet's vet.
Another method some have used for dogs with post-prandial problems  is to change the frequency of meals. Instead of feeding and giving insulin twice a day at morning and evening, the day's portion can be divided into 3 or 4 smaller ones. An example of this would mean 1/3 of the day's meal in the morning with insulin, and another 1/3 given without insulin around lunch time. The next 1/3 would be at the usual dinner time with evening insulin. A similar routine can be done with 4 small meals per day. (The same method can also be used for avoiding hypoglycemia with those who experience sharp blood glucose drops at the time the insulin peaks.)
Lente insulin can be very helpful in effectively dealing with dogs' post-prandial blood glucose spikes (also known as "food spikes").  Many vets prefer feeding, then giving insulin to dogs twice daily, 12 hours apart. If using Lente or mixed insulin R/NPH, the onset and peak will roughly match the expected post-prandial absorption of food.
Simple and complex carbohydratesEditKnowing that there are two kinds of carbohydrates--simple and complex--can help. The carbohydrates found in things like milk and sugar are classed as simple. They are rapidly converted into glucose. When dealing with hypoglycemia, this is why you're told to give syrup. It is turned into glucose and raises the blood glucose levels quickly. Since they are rapidly converted to glucose, their effects also fade rapidly. In hypoglycemia, this is why you need something after the syrup; syrup alone can get the blood glucose level raised, but it won't keep it there for an extended period.
Complex carbohydrates are found in things like bread and pasta--mostly anything made from grain. It takes longer for the liver to break complex carbohydrates down into glucose, making the blood glucose elevations from them more gradual--and longer lasting than those produced by the simple carbs. This is why food containing complex carbohydrates is to be given after a hypoglycemia incident--to make sure blood glucose levels don't revert to hypoglycemic ones when the short-term effects of the syrup are over.
Most of the food we give our pets contains carbohydrates of the complex variety. It means that when they raise blood glucose levels, they do not do it rapidly, as would be the case of syrup or sugar. It also means that the effects of most of the carbs found in the food start slower and last longer. Going to a multiple smaller daily meal plan would limit the amount of these complex carbohydrates entering the system at one time. This may help the insulin work better for a particular pet.
- ↑ Caninsulin-What to Feed the Diabetic Patient (Page11). Intervet.
- ↑ Bruyette, David (2001). Diabetes Mellitus: Treatment Options=Use of Lente Insulin in Canine Post-Prandial Blood Glucose Rises. WSAVA.
- ↑ Ruchinsky, Renee, et. al. (2010). Diabetes Management Guidelines for Dogs and Cats-page 7. American Animal Hospital Association.
- ↑ Greco, Deborah (2010). Treating Diabetes Mellitus in Dogs and Cats. Western Veterinary Conference.