Canine Gastric Dilatation-Volvulus (Bloat)
School of Veterinary Medicine
Purdue University, West Lafayette, IN 47907-1243
BLOAT NOTEs
News from the Canine Gastric Dilatation-Volvulus Research Program
Phone: (765) 494-6301 FAX: (765) 494-9830
June, 1995
EPIDEMIOLOGY PROGRAM RESEARCH TEAM
Department of Veterinary Pathobiology
Larry Glickman, VMD, DrPH
Diana Schellenberg, MS
Tana Lee
Department of Veterinary Clinical Sciences
Gary C. Lantz, DVM
William R. Widmer, DVM, MS
Center for the Human-Animal Bond
Nita Glickman, MS, MPH
Measurements and Bloat History: Data Obtained at the 1994 Great Dane National Specialty
At the invitation of the Great Dane Club of America (GDCA), a team from Purdue obtained measurement and bloat history data for 118 Great Danes at the GDCA National Specialty in Kansas City, Missouri, 25-26 October, 1994. This breed is of much interest because it ranked no. 1 in bloat risk among 24 breeds studied in a retrospective study.1
Each dog was measured, using a tape measure and a Canine Caliper (for depth and width of the chest and abdomen). Owners were asked for information about each dog, including whether the dog or any of its close relatives had ever had bloat, and whether any treatments were being used in an attempt to prevent bloat.2
The 118 dogs included 65 females and 52 males (sex not recorded for 1). The mean age of 115 dogs was 2.6 years, with a standard deviation (a measure of variability) of +2.1 years (age not recorded for 3 dogs). Twelve dogs (10%) had had a bloat episode.
Figure 1 below shows the distribution of abdominal depth/width ratios. Figure 2 shows the distribution of chest depth/width ratios. The black portion of a bar indicates the number of dogs with a history of bloat.
When dogs with moderate abdominal depth/width ratios (1.31-1.45) were compared with those who had lower ratios (0.70-1.30), the risk of bloat increased about 5 1/2 times; with the highest abdominal depth/width ratios (1.46-1.92), the risk increased almost 8 times. The increased risks associated with the greater abdominal depth/width ratios were statistically significant.
Measured dogs who had bloated were more likely to have a parent or sibling who had bloated; the differences were statistically significant (P<0.1). They were also more likely to have other relatives who had bloated:
| Relative | No. (%) of | No. (%) of |
| Who Bloated | Dogs with Bloat | Dogs without Bloat |
| Parent | 6/10* (60%) | 24/92 (26%) |
| Full sibling | 3/7 (43%) | 10/90 (11%) |
| Grandparent | 4/8 (50%) | 23/64 (36%) |
| Aunt or uncle | 5/8 (63%) | 19/59 (32%) |
| Offspring | 1/7 (14%) | 3/74 (4%) |
Treatments intended to prevent bloat were being used for only a small proportion of the dogs measured. Four (3%) had had prophylactic gastropexy; 8 (7%) were receiving antacid, 7 (7%) anti-gas medication, and 5 (5%) medication to increase stomach motility. Rational decisions about prophylactic treatment cannot be made until the effectiveness of the various methods is determined in future studies.
1. LT Glickman, NW Glickman, CM Perez et al.: Analysis of risk factors for gastric dilatation and dilatation-volvulus in dogs. JAVMA 204(4):1465-1471, 1994.
2. We wish to express appreciation to all the Great Dane owners and breeders who participated in this study.
Diet and Obesity in Female Pet Dogs
Every dog owner is concerned about the best diet for their dog. Veterinarians are concerned about obesity, perhaps the most common disease of dogs, which may put stress on the heart, joints, immune system, etc., as in humans. Despite the importance of diet to the health of dogs, there has been little quantitative information in the scientific literature about what dogs actually eat or about risk factors for obesity. Most of what we read is derived from marketing surveys by pet food companies, which merely tell us what commercial foods are sold. These surveys do not consider table food.
An article in the most recent issue of the journal Veterinary Clinical Nutrition1 reports the results of a dietary survey of adult female dogs conducted in the 1980s. Although not about bloat, this article presents information that will help us interpret the results of the case-control study of risk factors for bloat -- including diet. The study objectives were to:
Describe what pet dogs eat in terms of:
total energy intake
% of calories derived from different commercial food types and table foods, and
% of calories from fat, protein, and carbohydrate.
Calculate an obesity index for purebred dogs and identify risk factors for obesity.
The diet study was part of a larger study to identify risk factors and prognostic factors for breast cancer. It included 289 adult, female dogs: 146 with breast cancer and 143 with other cancers (excluding lipoma or liposarcoma). The 2 groups could be combined for this analysis because adult obesity and adult diet were not found to be associated with breast cancer risk.
Telephone interviews were conducted with dog owners, using an extremely detailed questionnaire. The diet information was collected for a time period 1 year before the cancer had been diagnosed. The owner was asked about the brand name and amount consumed of 4 dog food types (commercial canned, dry, semi-moist, and treats), and about the frequency, amount and preparation of 75 specific human foods. (The diet questionnaire itself had previously been tested and found to agree with 7-day dietary records kept by owners.)
A diet profile was constructed consisting of total food intake in grams of dry matter and total calories of metabolizable energy for each of the 4 types of dog food and for table food, and for each of 3 fuel sources (protein, fat, and carbohydrate) in the food.
Owners were also asked about their dog's body condition, i.e., whether the dog was thin, average, slightly overweight, or overweight, at age 9-12 months (juvenile) and 1 year before cancer was diagnosed (adult). For purebred dogs, the validity of the owner's assessment was confirmed by comparison with an obesity index (actual weight divided by the ideal weight for females of that breed). Obesity was defined as 15% or more above ideal body weight.
The dogs ranged in age from 5 to 17 years (mean 10.3); 155 (55%) had been spayed; 166 (74%) were purebred and 58 (26%) were mixed-breed; breed was not reported for 1 dog.
Diet
The average energy intake was almost 1,000 calories of metabolizable energy per day, with about 1/3 of the total calories from table food. (Some dogs were fed only table food.)
Obesity
About 40% of the dogs were overweight as adults and 6% as juveniles. Those who were overweight as juveniles were 1.5 times more likely to be overweight as adults than those who were thin as juveniles. There was no significant association between adult body condition and neuter status.
The mean obesity index (actual weight/ideal weight) for breeds with >9 dogs is summarized in the table:
| No. | Mean | |
| Breed | Dogs | Obesity Index |
| Cocker Spaniel | 11 | 0.94 |
| German Shepherd | 14 | 1.17 |
| Irish Setter | 9 | 1.04 |
| Miniature Poodle | 23 | 0.91 |
| Miniature Schnauzer | 17 | 1.26 |
| Toy Poodle | 10 | 0.81 |
| Other purebred dogs | 105 | 1.26 |
Figure 2 shows that carbohydrate consumption increased with breed size, while fat consumption tended to decrease with size. Protein intake was 25% for all sizes.
1. LT Glickman, EG Sonnenschein, NW Glickman, S Donoghue, MH Goldschmidt: Pattern of diet and obesity in female adult pet dogs. Vet Clin Nutr 2(1):6-13, 1995.
All in the Family? (Part 2)
We have mentioned before that, as in many human diseases, e.g., cancer, there may be a sporadic form and a familial form of bloat. In the sporadic form -- which probably accounts for most cases -- there may be no obvious genetic predisposition. In contrast, clusters of cases within families suggests a familial form, in which the genetic influence is strong. Understanding the genetic influence on bloat risk would help breeders made sound breeding decisions.
At the Irish Setter and Great Dane national specialties in 1994, owners were asked about the bloat history of relatives of the dog being measured (index dog). Index dogs who had bloated were more likely to have relatives who had bloated, thus suggesting a genetic link.
Some owners of Irish Setters and Great Danes have sent us pedigrees with bloat histories, which allowed preliminary evaluation of the influence of inbreeding on bloat risk. The coefficient of inbreeding is the probability that the 2 genes at the same site on the chromosome are identical because they have come from the same ancestor. This coefficient was higher for dogs who had bloated than for those who had not:
| No. of | Coefficient of | |
| Dogs | Inbreeding | |
| Irish Setters* | ||
| Dogs with bloat | 8 | 0.1306 |
| Dogs without bloat | 11 | 0.0924 |
| Great Danes** | ||
| Dogs with bloat | 3 | 0.1042 |
| Dogs without bloat | 14 | 0.0413 |
**Based on 4-generation pedigrees.
The differences in coefficients suggest that inbreeding may increase the risk, which in turn suggests that bloat has a genetic component in these breeds. However, more Irish Setter and Great Dane pedigrees are needed to complete this study (see col. 2).
Measurement data from Irish Setters at the 1994 show suggested that chest depth/width ratio is a significant bloat risk factor in this breed. Geneticist Dr. Robert Schaible and Irish Setter breeder Jan Ziech are conducting the first detailed pedigree and morphometry study of a familial cluster of bloat cases; this has been a labor-intensive effort! The first results suggest that in this family, the chest depth/width ratio is controlled by a single major gene rather than many genes having smaller effects.
In Memoriam
We are receiving donations in memory of dogs who died from bloat.
We are grateful
to Patricia Linke Frier for a donation in memory of Keesh, a Keeshond who
died from bloat. Keesh was 13 years old at the time of this photo.
We also express appreciation to George and Jane Cline, who made a contribution through the Heart of Alabama Great Dane Club in memory of Ch. Calico Rock's Bianca V Ridge-Lo. This Great Dane died from bloat at the age of 10 1/2.
Thank$! -- Epidemiologic studies of bloat and other areas of companion animal health at Purdue University School of Veterinary Medicine are made possible by contributions from the Morris Animal Foundation, animal health companies, and private foundations, and individuals whose dogs have experienced bloat. We welcome your comments, suggestions, and support.
$$ Those wishing to donate can send contributions to Purdue University in care of Dr. Larry Glickman, Bloat Research Program, Veterinary Pathobiology VPTH-101, Purdue University, West Lafayette IN 47907-1243.
Meet the Research Team --
Ken Simpson, a senior veterinary
student at Purdue, has worked with the Bloat Research Team since the summer
of 1994. Many readers would recognize his voice: he has conducted interviews
for the case-control and prospective survival studies. He also edited a
videotape on bloat and the Purdue research project. His involvement in
bloat research has fueled his interest in emergency medicine as a career.
Ken and his wife have 1 dog (Zeke, pictured above with Ken) and 2 cats. Apart from his veterinary studies, Ken spends his spare time playing guitar in a Vet School band.
From the Literature --
The most recent issue of Veterinary PreViews, a Purina publication which is sent to all veterinarians in the US, includes an article describing the bloat epidemiology research project at Purdue.1 The article presents an overview of the studies which have been mentioned in this and previous issues of BLOAT NOTEs.
Another Veterinary PreViews article2 summarizes current knowledge about gastric bacteria in dogs. Dogs' stomachs commonly harbor Helicobacter and Gastrospirillum species which resemble the bacteria (Helicobacter pylori) known to cause ulcers in humans, but their role in disease in dogs is not yet known.
Requests for copies can be addressed to Veterinary PreViews, Ralston Purina Company, Checkerboard Square, St. Louis MO 63164.
1. LT Glickman et al.: Epidemiologic studies of bloat in dogs. Veterinary PreViews 2(2):10-13, 15, 1995.
2. KA Eaton: Gastric bacteria in dogs and cats. Veterinary PreViews 2(2):3-6, 1995.
Editor's Corner -- Material in BLOAT NOTEs is not copyrighted and may be freely reproduced, with acknowledgement of the source. -- Diana Schellenberg