Dear Dr. John,

Our French Bulldog is almost two years old, and we were told to wait until now to breed her. Does that make sense? I did some homework, and it seems that dogs are pregnant for about two months or 63 days. If we do proceed, are there any special things we need to do during her pregnancy? I have also heard that bulldogs can have difficult pregnancies so should we be concerned?  By comparison, how long are gestations in other species? Z.A.

Dear Z.A.,

One is more likely to have a successful dog breeding by waiting until at least one or two heats have passed. First heats usually occur around 8-9 months but there is a lot of variability among breeds and dog size. Heats usually occur about twice a year and smaller breeds have shorter times between heats than larger dogs. Some breeds only go into heat once a year in the spring. If you want to ensure success, work with your veterinarian to determine optimal breeding times.

Once bred, pregnancy can be determined by any one of several methods such as blood work, palpation, and even radiography. Knowing the breeding dates can be helpful in planning for delivery which can vary around the 63-day mark with a range possible from 57 to 72 days. Type and amount of food will gradually increase throughout pregnancy but there is not much need to increase volume until around the start of the last three weeks.

As for difficulties associated with the breed, pregnancy is usually not the issue, but delivery can be. This is due to large head sizes and narrow hips and pelvis. This can make passage of puppies a challenge and may require C-section. It is not uncommon to plan for surgical delivery and Frenchies often have small litters of two to four puppies.

As a rule, the smaller the species, the shorter the gestation. Cats and dogs are about the same, but mice are pregnant for 3 weeks. rabbits 4-5 weeks, pigs 3 months, 3 weeks, and 3 days, cows 9 months, and horses 11 months. Good luck!

Dr. John de Jong is President of the World Veterinary Association. He owns and operates the Boston Mobile Veterinary Clinic and can be reached at 781-899-9994.