Q. What is a better food choice for a growing large-breed puppy: feeding puppy formula that's formulated for a 4-month-old, then changing to an adult formula? Or choosing a large-breed puppy formula from weaning until 2 years of age? Have you ever dealt with any cases of bloat in puppies younger than 7 months old?

A. Impressive improvements have occured in dog-food formulations over the past 10 years. The large-breed puppy formula is an excellent choice for very large dogs, such as Great Danes, Mastiffs and Newfoundlands. It is balanced with calories, protein, fat, vitamins and minerals (such as calcium and phosphorous) to help prevent some of the bone deformities that can occur in rapidly growing dogs.

For large dogs, such as Labrador Retrievers and German Shepherd Dogs, high-quality puppy food is fine up to about 6 months of age, sometimes longer. With either diet, do not supplement vitamins or minerals; they are all contained in correct amounts in high-quality diets.

Bloat, or gastric dilatation and volvulus can occur in puppies as young as 4 months old. This is a life-threatening emergency in which the stomach distends with gas, food or fluids, then twists on its axis. Gas builds up in the stomach, unable to escape, until the stomach is so large it blocks blood flow and interferes with breathing. Signs you might see are a large abdomen (that may be tympanic like a drum), pacing, anxiety and unproductive retching. Any dog that's suspected of bloating should be rushed to the nearest veterinary hospital.

Best,
Jon Geller, DVM