Introduction

Making improvements in health depends on many things. Near the top of the list are breeder skills, technology and the willingness to use new tools. These factors include management, pedigree analysis and environmental factors. The breeder skill called Breed Knowledge includes an understanding of the dreaded disorders in one’s breed. These are the diseases that can cripple, kill, cause blindness, or result in early death. In this regard, Gastric dilatation-volvulus (GDV), also called bloat, is a dreaded disease. It is the subject of this paper.

GDV occurs in dogs when the stomach distends with air and then while dilated, twists. This action interferes with the blood supply to the stomach and other digestive organs, blocks the passage of food, causes the stomach to distend, impedes the return of blood to the heart and results in reducing cardiac output. Blood and oxygen are deprived from tissues which in turn causes them to die releasing toxins into the blood stream which causes serious disturbances in heart rhythms and usually results in death unless treated.

This disease follows a predictable path that usually occurs in three phases.

Phase 1 – Dog will noticeably begin

1. Pacing, restlessness, panting and salivating.
2. Attempts to vomit.
3. Abdomen begins to enlarge

Phase 2- Dog begins to show signs of

1. Restless, whining, panting, salivating.
2. Unproductive attempts to vomit (every 2-3 minutes).
3. Gums become dark red.
4. High heart rate increases (180 to 210 BPM).
5. Abdomen enlarges and feels tight. When thumped with finger emits a hollow sound.

Recommended action: Immediately transport dog to Veterinarian!

Phase 3- Condition worsens

1. Gums become white or blue.
2. Dog unable to stand or has shaky stance.
3. Abdomen is hard and enlarged.
4. High heart rate accelerates (200 BPM or greater), pulse may become weak

Recommended action: Act quickly; transport dog to Veterinarian, use a Bloat Kit!

Death is often imminent!, typically, a dog will go from phase 1 - 3 in a few hours.

Bloat kits are available in our store.

Those who know this disease associate it with breeds that are large and deep-chested. They are thought to be at greatest risk because they have deep body cavities which allow space for the stomach to move and twist. Other factors thought to be associated with GDV include overeating and rapid eating, single daily feeding, high water consumption, stress, and exercise after eating. Unfortunately, only a few risk factors have been identified. Studies in the past have suggested factors that can influence GDV include dog-specific factors, management, environment, personality and a combination of these factors (body condition, genetics, age and sex). The breeds thought to be at greatest risk include the German Shepherd Dog, Great Dane, Collie, Weimaraners, Irish and Gordon Setters, Bloodhound, Akita, Saint Bernard, Mastiff, Standard Poodle, Labrador and Golden Retriever, Doberman Pinscher, and Chow Chow. Many other breeds have been known to suffer from GDV and they are also at risk.

A New Study

Early in 2010, Dr. Carmelo Battaglia of the American Kennel Club and Dr. Cindy Otto, at the University of Pennsylvania Veterinary collaborated with two other scientists: Marko Pipan, DVM, DACVECC and Dorothy Cimino Brown, DVM, MSCE, DACVS, to study GDV. Data about this disease show that the reported lifetime likelihood of developing GDV is 24% in large-breed show dogs and 21.6% in giant-breed show dogs. Other studies show that the mortality rate ranges from 10% to 33%. The high incidence of this disease coupled with a high mortality rate makes GDV a dreaded disease. Bell reported that Great Danes have the highest average like time risk of 42.4%.

Our study set out to evaluate the risk factors for GDV in privately-owned dogs across a wide geographic area. An internet-based survey was used to attract owners from more than 10 countries who reported on more than 2,551 privately-owned dogs. Data analysis and peer review resulted in identifying factors significantly associated with an increased risk of GDV.

These factors include:

1. Dry kibble
2. Anxiety
3. Born in the 1990's
4. A family pet
5. Spending at least 5 hours a day with the owner.

Based on our results we were able to identify factors associated with a decreased risk of GDV.

They include:

1. Playing with other dogs
2. Running the fence after meals
3. Fish and egg dietary supplements
4. Spending equal time indoors and outdoors

Our survey differed from other studies in many ways. It was live between June 9, 2010, and August 8, 2010. Survey participants were recruited by posting links to websites used by dog owners.

Information was disseminated at meetings of dog owners and in newsletters for dog owners and breeders (e.g., American Kennel Club-Canine Health Foundation), e-mail lists for dog owners and breeders (e.g., 9/11 search dogs and agility groups), owner-oriented dog publications (e.g., Celebrating Greyhounds magazine), and e-mails forwarded by participants. Because of access to the Internet, our worldwide survey was available to individuals in any country. The distribution of the survey was not restricted or monitored. Any dog owner that came across the survey could answer the questionnaire and individuals were encouraged to share the access link with other dog owners.

Design of Study

Our survey was divided into 3 parts: (general, management, and environment). The general section included background questions applicable to dogs with GDV, and questions applicable to dogs without GDV. This section focused on demographic factors including the year of birth, breed, sex, neuter status and purpose (i.e., family pet, performance dog, competitive sports dog, working dog, show dog), and the country and postal code at which the dog lived. On the basis of the responses, the respondents were divided into two groups: dogs with a GDV that were treated via surgery and dogs without GDV (control group). In the GDV group we included dogs that underwent surgical treatment as well as dogs that died or were euthanatized because of presumed or confirmed GDV without surgery. Respondents with a dog with a GDV requiring surgery were directed to a series of 44 questions organized into four categories.

The first category (general information) included dog-specific factors such as age at time of GDV; history of GDV in relatives; body condition score (numerical rating scale of 1 to 9); history of surgery, anesthesia, diarrhea, or other illness; speed of eating (numerical rating scale of 1 to 5); and tendency to sleep on its back.

The second category addressed information regarding management factors such as dog activities (i.e., dog shows, field training, schutzhund or working activities, obedience training, agility); type of diet (i.e., dry kibble, canned food, raw commercial, cooked homemade, raw homemade); frequency of feeding and supplements (i.e., eggs, cod liver oil, fish, vitamins, cooked chicken, raw chicken, cheese, yogurt, coat enhancers) and table foods; feeding from a raised bowl; postprandial housing (i.e., kenneled, loose indoors, loose outdoors); the most relevant time (i.e., immediately, 30 minutes, 1 hour, 1 to 3 hours, 3 to 6 hours, or more than 6 hours after eating) and type of postprandial activities (i.e., running outside, running inside, playing with other dogs, running the fence, jogging with owner, kenneled); lifestyle (i.e., predominantly indoors, predominantly outdoors, both indoors and outdoors); routine housing (i.e., loose, crate, pen); predominant company (i.e., alone, other dogs, family, no family); number of hours spent with the owner each day; number of days spent with the owner each week; night time housing (i.e., indoors, outdoors, or both); and company (i.e., owner or handler, familiar person, unfamiliar person, alone) and location (i.e., home, boarding, training facility, other familiar environment, unfamiliar environment, traveling) during the time leading up to the GDV event.

The third category focused on environmental factors such as place of residence (i.e., urban, suburban, rural); presence of other dogs and cats in the household; recent addition of a new pet or person to the family; and season, outside temperature (numerical rating scale of 1 to 5, where 1 = subfreezing and 5 = extremely hot), and presence of estrus in sexually intact dogs at the time of GDV. The last set of questions referred to dog personality factors, such as excitable behaviors such as barks at: knocks on the door, at strangers, at other dogs, is hard to control, chases tail, spins out of control, acts oblivious, runs the fence, plays with dogs. We also attempted to measure anxiety (numerical rating scale 1 of 9) and energy level (numerical rating scale of 1 to 9).

A control group (dogs without GDV) was part of this study. Owners with dogs who did not have GDV were asked to respond to thirty two questions that were used to study other related areas not usually included in other GDV studies.

Statistics

Our published report included descriptive statistics such as median values and ranges. Categorical data was expressed as frequencies. Logistic regression analysis was used to evaluate risk factors for surgical DV. Table 1 provides an overall view of the study for dogs affected with GDV and the control group along with the country where the owner resides.

Table 1 Characteristics of Study

Factor	Control Group	Percent	GVD Group	Percent
	N = 1,437		N = 1,144
Country
USA	1,229	85	956	86
Canada	102	7	102	7
UK	28	2	40	3.5
Australia	38	3	32	3
Other	40	3	35	3
Decade of Dog Birth
1960’s	102	7	158	14
1990's	464	32	512	46
2000-2010	871	61	444	40
Breed
German Shepherd	153	11	148	13
Great Dane	145	10	136	12
Standard Poodle	54	4	62	6
Doberman	63	4	42	4
Other purebreds	977	68	701	63
Mixed breeds	45	3	25	2
Sex & neuter status
Female spayed	419	29	284	26
Female intact	281	20	199	26
Male castrated	315	22	328	29
Male intact	422	29	303	27

Nutrition and Management

Many believe that nutrition is a contributing factor for GDV. Our findings show that dietary management is a contributing factor. Type of food, frequency of meals, and volume fed were evaluated. Commercial dry dog food was implicated as causing GDV in one study. However, in a recent control study, feeding a commercial dry food did not increase the incidence of GDV (Raghavan). However, feeding a single type of food was found to increase the likelihood of gastric dilatation, whereas the addition of table foods to a usual diet consisting primarily of dry dog food reduced the risk of acute GDV. Dogs fed a large volume of food per meal (regardless of the number of daily meals) were at a significantly increased risk of GDV, with the highest risk in dogs fed a larger volume once daily. Contradicting previous management recommendations we noted that feeding from an elevated feed bowl, moistening of dry food prior to feeding, and restricting water and exercise before and after meals were found to increase the risk of GDV.

Environment

The data suggest that there are environmental factors that may also influence the risk for GDV. For example, large-breed dogs living in a rural residence represented a higher risk, but for giant-breed dogs, an urban residence was associated with increased risk of GDV. In military working dogs in Texas, GDV was most common in the cooler months (November through January) and least common in the hot months (June through August). This seasonal variation was not detected in client-owned dogs in Switzerland, where warmer environmental temperatures were significantly associated with the occurrence of GDV.

Personality

Our data suggest that the interaction between a dog and its environment represents an important component of risk. Our study supports the notion reported by Glickman (2000) that personality factors such as aggression toward people and fearfulness or agitation in response to strangers or environmental changes were associated with an increased risk of GDV, whereas a "happy" and easy going temperament, submission to other dogs or people, high activity level, and attending dog shows decreased the risk of GDV. Studies by (Glickman, 1997) and Brockman suggest that a variety of stressful events, including kenneling and riding in the car, appeared to precipitate acute GDV episodes. Other studies have also evaluated risk factors by focusing on unique populations of dogs (i.e., show dogs and military working dogs), however most of these studies included relatively small numbers of dogs affected with GDV.

Those who train dogs or specialize in canine behavior use the word “reactivity” to describe dogs that lunge repeatedly, bark furiously at the sight of another dog, spin out of control and act oblivious to efforts to intercede. These responses are not normal according to Dodman, a veterinary behaviorist who identifies these dogs using the term “reactivity”. In his book “Dogs Barking Badly” he says it is normal for dogs to become aroused or exited when their owners come home or when they see cats, squirrels and other animals or when there is a knock on the door. This kind of arousal is normal and can lead to barking, the raising of their tail and ears and the bristle of their coat. Miller (2009) reported that the tendency to be aroused in the presence of other dogs is heritable and that those who cannot handle stress and show reactive behavior are thought to be different from well-adjusted dogs. While this behavior is often associated with aggression, the underlying cause may be a lack of adequate stimulation and socialization during the first year of life. Thus it is easy to assume that dogs that spin out of control, become frantic or are not easily controlled may be at risk. Our study supports the notion that dogs with calmer behavior are at less risk for GDV.

Group-specific information

The median age for affected dogs was 6 years. In 676 cases diarrhea was present in 14% of the dogs and anesthesia was performed in 12% of dogs 72 hours prior to the GDV. On the day of the GDV, most dogs were at home and in the company of the owner or a handler. The outside temperature was most commonly reported as the median (3) on a scale between subfreezing (1) and extremely hot (5). More specifically, GDV was observed (P < 0.001), with the smallest number of GDV cases reported during the winter and the most number of GDV cases reported during the spring. In sexually intact dogs, 8.5% females were in season, and 16.5% of males had a bitch in season nearby during the week prior to the GDV.

New Factors and Conclusions

Our study identified several new factors associated with an increase and decrease risk for GDV. However, since data can sometimes be given more than one meaning we carefully noted that some factors are likely to be a result of the nature of the survey. For example, the increased risk associated with dogs living in the UK could represent a true risk, although we were careful to note that it is more probable that respondents in the UK were more likely to complete the survey if their dog had experienced a GDV. Another example was the increased risk associated with being born in the 1990’s. This we considered to possibly reflect the fact that younger dogs (those born in the 2000’s) may go on to develop a GDV with age, or that the person completing the survey for a dog without a GDV was more likely to report on a currently owned dog, whereas the GDV dogs may have been previously owned dogs. Alternatively, this increased risk associated with being born in the 1990’s could be a reflection of a real decrease in incidence of GDV because of improved owner education, management, breeding strategies, or formulations of dog food.

Of the personality-associated factors with the occurrence of GDV, positive behavioral traits ( happy and easygoing temperament) and submissive behaviors ( toward other dogs or people) were associated with a decreased risk of GDV; negative behavioral traits ( fearfulness or agitation in response to strangers or environmental changes) and aggression to people were associated with an increased risk . We also noted that there was a small but significant association between GDV and the owner’s assessment of their dog's anxiety. The difference in anxiety scores between GDV cases and the controls group is unlikely to be detected clinically because of the simplistic scoring system that we employed in the survey; however, given the large number of dogs included in the survey, this factor was determined to be significant.

Commercial dry dog food was identified as a risk factor. This finding is consistent with a study of acute gastric dilatation by Van Kruiningen et al., in young Irish Setters. It is unknown if this risk is associated with the tendency for the kibble to expand, added weight of a kibble meal, the influence on gastric emptying, or some other management feature related to feeding kibble. Burrows evaluated the influence of dietary composition on gastric emptying and motility in healthy large-breed dogs fed once daily, and found that emptying was not affected by dietary composition (canned meat-based formula, dry cereal-based formula, dry cereal-based formula mixed with water).

Unlike the study in Irish Setters, the frequency of feeding did not influence the occurrence of GDV. Dogs that were predominantly pets (as opposed to performance or show dogs) and spent at least five hours a day with their owners were at higher risk. This finding could be influenced by dog-specific factors such as fitness and activity levels and management factors associated with more extensive contact. Glickman (1996) found that large-breed dogs who attended dog shows had a decreased risk of GDV however; this was not a significant factor in our risk model. We did note that there was no detectable influence based on body condition; however, assessment of body condition by the owner may not have been as objective as that of a trained professional.

The major categories of management that were associated with a decreased risk were dietary supplements and activity. The addition of eggs or fish to the diet was associated with a decreased risk of GDV. The mechanism by which these, but not other supplements (e.g., cod liver oil, vitamins, cooked or raw chicken, cheese, yogurt, or coat enhancers) were associated with a decreased risk of GDV is unknown. Supplementing dry dog food with table food was previously recommended to decrease the risk of GDV, but our study found that feeding table scraps had no significant effect on GDV. We found that moderate activity on gastrointestinal motility could potentially explain the observed protective effect in GDV dogs that spent equal time indoors and outdoors (versus primarily indoors or primarily outdoors) and the likely higher levels of physical activity.

In a study by Guilford it was reported that postprandial exercise has been implicated in dogs as a risk factor for GDV. The recommendation offered was “that intense physical activity should be restricted for 2 hours after meals." Contrary to this finding, our study of 1,637 show dogs found that restricting exercise before and after eating increased the risk of GDV in large-breed dogs but not in giant-breed dogs. Glickman also found that there was no advantage in restricting exercise before or after eating and we noted that dogs allowed play time with other dogs or running the fence after eating had a significantly decreased risk of GDV. Interestingly, the time of activity after eating had no impact on the GDV risk. On the basis of our results and those reported by Glickman (1991) it appears that moderate physical activity after a meal may decrease the risk of GDV. It is also possible that owners of dogs that are at higher risk because of familial tendencies (pedigree analysis) or conformation (body depth) may be more vigilant and might be more likely to restrict their dog's activity, thereby introducing a bias against restricting activity. Bell suggested that dogs do not inherit bloat, but only a predispotion for the condition and that the best selective tool against bloat is chest-depth to chest-width ratio and those whose littermates did not bloat.

This study was not designated to evaluate pedigrees or the influence of stud dogs which are factors that’s which continue to be a worrisome concern. Since this was an owner-based survey, we did not have a means to quantify chest depth or conformation. However, consistent with Glickman’s study (1997) females overall had a decreased risk of GDV, compared with males. However, sexually intact female dogs were found to be at increased risk. This dichotomy may be associated with hormonal status and breeding history. The results of our study suggest changing management after meals by relaxing the previous recommendations for activity restriction after meals. In addition, regular moderate outside activity should be encouraged because dogs that spent an equal amount of time indoors and outdoors had a decreased risk of GDV. Dietary management appears to play an important role, and dry kibble may not be the best choice for dogs at risk for GDV; however, supplements with fish or eggs may reduce this risk. Our study was unable to show an association between GDV and feeding frequency, speed of eating, or eating from a height; therefore, no specific recommendations concerning these factors can be made at this time.

It is important to realize that despite multiple studies over the past four decades; few consistent risk factors have been clearly identified. We do believe that owners should be educated on the signs of early recognition of GDV so that prompt treatment can be pursued. Until more definitive preventive strategies become available owners should consider owing a bloat kit (available at our store) and prophylactic gastropexy for dogs at high risk for GDV (Rawlings, Ward).

References

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