Nutritional Management of Gastrointestinal Disease in Brachycephalic Dogs

Over the past 20 years, the number of dogs affected by brachycephalic obstructive airway syndrome (BOAS) has increased, resulting in large part from the popularity of brachycephalic breeds.¹ Brachycephalic dogs have been bred to accentuate features that potential owners look for; however, breeding to enhance specific brachycephalic features has had a detrimental repercussion on the dogs’ health. Veterinary teams are aware of the respiratory consequences of BOAS, but gastrointestinal (GI) signs may also be exhibited. Patients will benefit if the veterinary team follows a systematic approach to characterize the nature of the problem and develops the most prudent treatment and follow-up plan.

Recent studies highlight the fact that the incidence of gastroesophageal junction abnormalities and hiatal hernias have been underestimated in brachycephalic dogs.^2-4 In addition, video fluoroscopic swallowing studies have documented esophageal dysmotility with prolonged esophageal transit time and gastroesophageal reflux in brachycephalic dogs.⁴

GI signs in brachycephalic dogs usually need medical management, including dietary modifications and pharmaceutical agents. In patients with hiatal hernia that remain unresponsive to medical management, surgical management may be considered. Various grading schemes have been published for assessing brachycephalic dogs with BOAS before and after surgery and include respiratory signs (e.g., snoring, inspiratory efforts, exercise intolerance, syncope) and GI signs (e.g., ptyalism, regurgitation, vomiting). They are graded on frequency and are scaled from 1 (mild) to 3 (marked).⁵

BOAS is progressive; age at presentation ranges from a few months to a few years. After 5 years of age, a first episode of BOAS is highly unlikely.⁶ A definitive diagnosis involves history taking, physical examination, detailed clinicopathologic investigations, and diagnostic imaging.

This article focuses on medical and nutritional management of BOAS and GI signs in brachycephalic dogs and provides a case report in SOAP (subjective, objective, assessment, and plan) format.

History and Physical Examination

Because brachycephalic dogs may exhibit various combinations of clinical signs, a comprehensive history is essential. Time should be spent questioning the client as clients may be unaware that their dog has a problem because they often consider stertor, loud breathing, and regurgitation to be normal for their dog.⁴ History taking should focus on ascertaining the presence of GI signs.^5,7

Brachycephalic breeds experience anatomic and pathophysiologic changes associated with their wide and short skull. Although the alterations to skull shape are visible, many abnormalities also occur in soft tissue structures (e.g., elongated soft palate, macroglossia, stenotic nares, undersized nasal chambers, malformed and aberrantly growing nasal conchae, tracheal hypoplasia, acquired laryngeal complications).^6,7

Clinical signs of BOAS can be mostly respiratory, or they may involve a mix of respiratory and GI signs. Clinical signs associated with the respiratory tract (e.g., intolerance to exercise and heat, frequent disruptions in sleep, syncope) are common, but GI signs are being increasingly reported for dogs with BOAS (e.g., ptyalism, excessive swallowing attempts, regurgitation, eructation, vomiting, changes in appetite) and their severity strongly correlates with that of respiratory signs.^5,8 The association between respiratory and GI signs in brachycephalic dogs is further supported by clinical improvement and fewer postsurgical complications when GI signs are treated.⁶ Both systems may be affected as follows by increased negative pressure within the upper airways⁶:

• Secondary respiratory abnormalities
  • Everted tonsils
  • Laryngeal and tracheal collapse
  • Everted laryngeal saccules
• Digestive tract lesions
  • Hiatal hernia
  • Gastroesophageal reflux

Physical examination should include initially checking the dog’s phenotype (e.g., skull dimensions, nares), the respiratory cycle (especially inspiratory effort), and spontaneous respiratory noises (tachypnea), after which the head and neck are examined. Examining the oral cavity is often difficult because brachycephalic dogs struggle to breathe with their mouth wide open. Thoracic auscultation should be performed, although loud referred upper respiratory tract noises make this examination potentially challenging as well. Last, the rest of the body should be examined.

Diagnosis

Accurate diagnosis of GI tract disease in brachycephalic dogs usually requires detailed diagnostic investigations (e.g., clinical pathology, thoracic radiographs, fluoroscopic assessment of swallowing function, upper airway and GI endoscopy). The most common GI signs are regurgitation and vomiting, but the signs in BOX 1 may be present as well.

The diagnostic approach involves endoscopy of the upper airways and the GI tract. Even in brachycephalic dogs without any GI tract signs, lesions of the upper GI tract are often detected endoscopically. The diseases most commonly affecting the GI system in brachycephalic dogs are listed in BOX 2.

Stomach and swallowing problems are associated with respiratory obstruction. Reflux of stomach contents into the esophagus generates pain and inflammation. Intensifying that problem is retention of food in the stomach for prolonged periods, which creates a sensation of nausea and increases the potential for vomiting and/or stomach acid reflux. Although those problems may sound separate from the respiratory disorder, reflux, regurgitation, and even herniation of part of the stomach into the chest cavity result from the extreme inhalation efforts made against the upper airway obstruction that comes from the shape of the brachycephalic head.⁹

Treatment

Medical Management

Medical management is the most common approach for all brachycephalic dogs with GI signs and includes dietary modifications and pharmaceutical agents. The agents most commonly used for brachycephalic dogs with GI disease are antiemetics, acid-blocking drugs, mucosal protectants, and prokinetic agents.⁶ However, clinical trials reviewing the efficacy of these drugs when used in brachycephalic dogs with GI disease have not yet been performed. Acid-blocking drugs and mucosal protectants (e.g., sucralfate) are indicated for dogs with evidence of esophagitis. Antiemetics are indicated if vomiting is confirmed.

Body Condition Score

The veterinary team should measure the body condition score (BCS), a physical assessment of body fat mass, of every brachycephalic patient that visits the hospital and educate owners as to the value of keeping their dog at an ideal BCS. The 9-point BCS scale is validated to correlate with body fat percentage using DEXA (dual-energy X-ray absorptiometry).¹⁰ Each incremental increase in BCS is equivalent to a 5% increase in body fat percentage, and each BCS greater than 5 out of 9 is equivalent to being 10% overweight. Obesity, as quantified by using BCS, is a strong risk factor for BOAS. The effect of obesity on respiratory function incorporates a decrease in minute volume with an increase in respiratory frequency, exercise intolerance, and a decrease in estimated arterial oxygen saturation.^11,12

Key Nutrients

When managing GI signs in a brachycephalic patient, the veterinary healthcare team should be aware of key nutrients and their effects. It is imperative that these key nutritional factors be understood, implemented, and communicated to the client.

Water

Water is vital when working with patients with GI disease because of the potential for life-threatening dehydration from excess fluid loss and the potential inability of the patient to replace the lost fluid. If the brachycephalic patient is dehydrated, the dog’s hydration status should be monitored and supported with subcutaneous or intravenous fluids.

Protein

Nutritional therapy for patients exhibiting GI disease should not provide excess protein. Products of protein digestion increase gastrin and gastric acid secretion.^13,14 Novel ingredient diets or elimination foods have been recommended. Ideal elimination foods should

• not have excess protein
• have highly digestible protein (≥ 87%)
• contain a limited number of novel ingredients

Protein quality plays a role in caring for brachycephalic dogs because the higher the quality, the higher the digestibility. In addition, high-quality protein helps decrease fermentation products,¹⁵ resulting in reduced odor and flatulence. A food containing a protein hydrolysate may also be used in nutritionally managing GI signs in brachycephalic patients.

Fat

Foods lower in fat are recommended for brachycephalic dogs with GI issues. Solids and liquids higher in fat empty more slowly from the stomach than comparable foods with less fat.¹⁴ Fat in the duodenum stimulates the release of cholecystokinin, which delays gastric emptying.

Fiber

Foods containing gel-forming soluble fibers should be avoided in dogs with GI disease because these fibers increase the viscosity of ingesta and slow gastric emptying.^13,14 Those fibers include pectins and gums (e.g., gum arabic, guar gum, carrageenan).

Nutritional Management Strategies

Nutritional modifications (BOX 3) are intended to promote passage of food through the GI tract,¹³ which in turn decreases the tendency for regurgitation, vomiting, or gastroesophageal reflux.

Food Form and Temperature

Moist food is best because moist foods reduce gastric retention time. For the same reason, the veterinary healthcare team should educate clients to warm foods to between room and body temperature (21 °C to 38 °C [70 °F to 100 °F]).

Bowls

A recent suggestion to aid brachycephalic patients with GI issues concerns the type of bowl from which they are eating (FIGURE 1). Veterinary teams should consider discussing certain bowls with clients with brachycephalic patients. Bowls for brachycephalic dogs (e.g., Enhanced Pet Bowl; Enhanced Pet Products, enhancedpetproducts.com) are made with a 45° angled ledge to improve the pet’s posture while eating and relieve some of the strain on the cervical vertebrae and spine in breeds that are prone to intervertebral disk disease. Those bowls promote chewing and slower eating, which helps the pet’s digestion. They are also said to help reduce bloat and obesity and aid in providing proper GI motility.¹⁶ Bowls for brachycephalic dogs help lessen the amount of gulping and air swallowed and help slow down the fast brachycephalic eater.

Figure 1. Brachycephalic dog eating from elevated bowl.

Other

Larger meals empty more slowly from the stomach than smaller meals. Therefore, feeding small meals more often throughout the day is recommended. In addition, liquids empty more quickly from the stomach than solid foods due to lower digesta osmolality.¹⁷ Water empties most quickly, and liquids containing nutrients are emptied more slowly. High-osmolality fluids empty more slowly than dilute fluids. Solids are the slowest to be emptied from the stomach. It has been shown that dry foods are emptied from the stomach of pets more slowly than moist foods.^18,19 The ideal food consistency for patients with GI disorders is liquid or semi-liquid. Feeding food of a different consistency or adding water to a dry food will improve GI motility.

Case Report

Lily, a 2-year-old spayed female French bulldog, presented to the hospital for increasing bouts of client-described regurgitation, eructation, and excessive swallowing attempts.

Subjective: The client describes Lily regurgitating roughly 1 to 2 hours after her meals, consistently “burping” throughout the day, and doing what appears to be trying to swallow as if she has something stuck in her throat. The client states that Lily tires easily after short walks of about 5 minutes. For all of her life, Lily has been fed commercially prepared dry kibble.

Objective: Lily has a history of stenotic nares and an elongated soft palate and surgery to correct both. Before surgery, her brachycephalic grading score was 2.5 out of 3. During the examination, the patient is actively drooling and swallowing multiple times. The grading score assigned today is 2 out of 3. Lily’s BCS is 7 out of 9. Her weight is 11.4 kg (25 lb). Endoscopy findings include distal esophagitis and mucosal irregularities.

Assessment: Lily exhibits GI tract signs secondary to BOAS, which was diagnosed and managed earlier in life with corrective surgery to her nares and elongated soft palate. She is also 20% over ideal body weight (BCS 7/9). Her GI signs and findings suggest esophagitis, gastroesophageal reflux, delayed gastric emptying, and gastritis.

Plan: Management includes dietary modifications and pharmaceutical agents. Acid-blocking drugs and mucosal protectants (e.g., sucralfate) are indicated. Nutritional management includes recommended modifications such as changing to a lower-fiber, lower-fat food with a highly digestible protein source; adding water to the kibble to alter the consistency; and feeding smaller meals more often throughout the day. It is recommended that Lily eat from a bowl for brachycephalic dogs to improve her posture while eating and to promote chewing and slower eating, which will help Lily’s digestion and provide proper GI motility. Her kilocalories will be calculated by using the obesity factor, and gradual safe exercise will be implemented to help decrease Lily’s obesity. The client will be educated on the GI effects of BOAS and the recommendations made to alleviate these signs.

Summary

BOAS has increased significantly due to the popularity of brachycephalic breeds. Along with the respiratory signs the veterinary community is witnessing, signs involving the GI tract are increasing. Recognition and understanding of BOAS signs and the accompanying GI signs will help the credentialed veterinary technician and the entire veterinary team work with clients with brachycephalic dogs to ensure the patients’ wellbeing. Veterinary teams should implement a systematic approach to characterize the respiratory and GI issues, as well as the most practical management and follow-up plan.