Since 1994, Glickman and associates at Purdue University School of Veterinary Medicine have followed nearly 2000 dogs of 11 large and giant breed dogs, in a controlled study of canine bloat. The breed with highest lifetime likelihood of developing bloat is the Great Dane (42.4%). Other deep-chested pure or mixed breeds also are at high risk, especially the Bloodhound, Irish Wolfhound, Irish Setter, Akita, Standard Poodle, German Shepherd Dog, and Boxer. The predispositon to develop bloat is believed to be a polygenic, heritable trait. Risks factors for bloat in addition to breed type include deep and narrow chests, lean weight versus overweight, older age, gulping food quickly (15% increase, presumably from more swallowing of air), and dogs with fearful, nervous, or aggressive temperament, eating one large meal daily, and stress. For large breeds, the risk of bloat goes up 20% for every year above age 5, whereas in giant breeds, it increases 20% for each year after age 3. About 30% of dogs that develop bloat die or are euthanized. First degree relatives of dogs with bloat history have a 63% greater risk of also developing bloat. Additionally, there has been a 1500% increase in the incidence of canine bloat in the last 30 years. As this has coincided with the increased feeding of dry dog foods, mixing it with home-prepared or canned food has been shown to decrease the bloat risk. While raising the height of food and water bowls has been touted as being preventive, when studied, the risk of bloat actually increased by 110%.

Factors found not to be associated with increased bloat risk include: the degree of exercise before or after eating, recent vaccination, brand of dog food consumed, and timing or volume of water intake before or after eating. The best selection pressure against producing dogs at increased bloat risk is to breed those with lower chest-depth to chest-width ratios, and whose littermates have not bloated.
Reference: Bell. AKC Gazette 120 (4): 26-27, 2003.

Lifetime probability of death from gastric dilation-volvulus (GDV) was estimated for the Great Dane, Irish Setter, Rottweiler, Standard Poodle and Weimaraner based on published breed-specific longevity and GDV incidence. Mean lifetime GDV risk ranged from 3.9% in the Rottweiler to 36.7% in the Great Dane. A decision-tree analysis determined that prophylactic gastropexy was the preferred course of action for all breeds examined, with reduction in mortality (versus no gastropexy) ranging from 2.2-fold (Rottweiler) to 29.6-fold (Great Dane). The procedure was cost-effective when the lifetime risk of GDV was 34%. However, prophylactic gastropexy raises ethical issues that need to be considered by veterinarians and dog breeders.
Reference: Ward, Patronek, Glickman. Prev Vet Med 60: 319-29, 2003.

Puppies < 8 weeks old have proteinuria, glucosuria, and decreased urine concentration, which has been considered normal, presumably due to immature renal function. A recent study of voided urine from 118 apparently healthy, random-source puppies found mean urine specific gravity to be significantly lower in puppies 0-3 weeks old when compared to those 4-24 weeks old. Among the age groups studied, there was no difference in the frequency of positive protein or occult blood on dipstick analysis, and none of the samples had positive glucose, ketone, bilirubin, or urobilinogen reactions. In 41 samples, urine sediment was evaluated. Most common sediment findings were epithelial cells (83%), white blood cells (44%), and crystals (37%).
Reference: Faulks and Lane, JAAHA 39:369-378, 2003.