Videofluoroscopic swallow study features of lower esophageal sphincter achalasia-like syndrome in dogs

Management and outcomes of 13 dogs treated with a modified Heller myotomy and Dor fundoplication for lower esophageal sphincter achalasia-like syndrome

OBJECTIVE

To report the management and outcomes of dogs treated for lower esophageal sphincter achalasia-like syndrome (LES-AS) with modified Heller myotomy, Dor fundoplication, and with the use of a temporary gastrostomy tube.

STUDY DESIGN

Retrospective.

SAMPLE POPULATION

Thirteen client-owned dogs.

METHODS

Medical records and a client survey were used to assess frequency of vomiting/regurgitation, quality of life (QoL), bodyweight, and feeding modifications at the following time points: prior to referral, postoperatively from discharge to first recheck (4-6 weeks), and from first recheck to survey (48 months). Postoperative and gastrostomy tube complications were surveyed and recorded. Pretreatment and 4-6 weeks postoperative videofluoroscopic swallow studies (VFSS) were compared. Two-sided t-tests were used to compare outcomes between survey time points.

RESULTS

Postoperative VFSS scores (available in 9 dogs) improved over preoperative scores in 6 dogs, and 12/13 dogs survived to discharge. One dog was euthanized 3 days postoperatively due to aspiration pneumonia. Postoperative gastrostomy tube complications occurred in half of the dogs that survived to discharge. According to the owners, scores assigned to vomiting/regurgitation improved by 180% (P = .004), QoL by 100% (P = .004), and bodyweight by 63% (P = .035).

CONCLUSION

Modified Heller myotomy with Dor fundoplication and the use of a temporary gastrostomy tube improved clinical signs and owners' perceived quality of life in half of the dogs treated for LES-AS in our clinical setting. Oral sildenafil therapy discontinued postoperatively suggests that surgery was equally efficacious.

CLINICAL SIGNIFICANCE

Modified Heller myotomy with Dor fundoplication and temporary gastrostomy tube is a treatment option with potentially sustained benefits for dogs that have LES-AS.

Extraesophageal reflux and reflux aspiration in dogs with respiratory diseases and in healthy dogs

BACKGROUND

Salivary bile acids are used to diagnose extraesophageal reflux (EER) and to evaluate the risk of reflux aspiration that is associated with respiratory diseases in dogs.

OBJECTIVES

To study total bile acid (TBA) concentrations in saliva and in bronchoalveolar lavage fluid (BALF) to investigate EER and reflux aspiration in dogs with respiratory diseases and in healthy dogs.

ANIMALS

 Thirty-one West Highland White Terriers (WHWTs) with idiopathic pulmonary fibrosis (IPF), 12 dogs with inflammatory airway disease (IAD), 6 dogs with recurrent pneumonia (RP), 26 brachycephalic dogs (BD), 27 healthy WHWTs (HW), 52 healthy dogs (HD). All privately-owned dogs.

METHODS

Saliva and BALF were collected from dogs in each group.

RESULTS

Salivary TBA concentrations were higher in IPF (median 0.1692 μM, interquartile range [IQR] 0.1115-0.2925 μM, Cohen's d 3.4, 95% confidence interval [CI] 2.2-4.0, P < .001) and BD (0.0256 μM, IQR 0.0086-0.0417 μM, d 0.5, CI -0.1 to 1.1, P = .003) compared to HD (0 μM, IQR not quantifiable [n.q.]-0.0131 μM). Bronchoalveolar lavage fluid TBA concentrations were higher in IPF (0.0117 μM, IQR 0.0048-0.0361 μM, d 0.5, CI 0-1.1, P < .001) compared to HD (0 μM, IQR n.q.-0.0074 μM).

CONCLUSION AND CLINICAL IMPORTANCE

Extraesophageal reflux and reflux aspiration occur in healthy dogs and those with respiratory diseases.

Incidence, clinical signs, and videofluoroscopic swallow study abnormalities associated with airway penetration and aspiration in 100 dogs

BACKGROUND

Videofluoroscopic swallow studies (VFSS) utilizing penetration-aspiration (P-A) scoring assesses airway protection in people. On VFSS, penetration (ingesta or secretions immediately cranial to the vocal folds) and aspiration (material caudal to the vocal folds) are associated with increased risk of lung injury in people. Penetration-aspiration (P-A) scoring has been validated in animal models, but the incidence of P-A, clinical signs (CS), and dysphagic disorders associated with P-A in dogs are unknown.

OBJECTIVES

Using VFSS, identify the incidence of P-A, compare CS between dogs with and without P-A, and identify predisposing dysphagic abnormalities for P-A.

ANIMALS

One hundred client-owned dogs.

METHODS

Sequential VFSS and associated medical records from dogs presenting to the veterinary teaching hospitals at Auburn University (n = 53) and the University of Missouri (n = 47) were retrospectively reviewed. Statistical comparisons were made using Mann-Whitney tests, one-way analysis of variance (ANOVA) on ranks, multiple linear regression, and Spearman rank order correlation (P < .05).

RESULTS

On VFSS, the incidence of pathologic P-A was 39%. No significant differences in CS were found between dogs with or without P-A (P > .05), with 14/39 dogs with P-A presenting without respiratory CS. Pharyngeal (P < .001) and esophageal (P = .009), but not oral-preparatory (P = .2) dysphagia was more common with P-A. Pharyngeal weakness (P < .001) and esophago-oropharyngeal reflux (EOR; P = .05) were independent predictors of P-A and were moderately and weakly positively correlated with P-A score respectively (P < .001, r = 0.489; P = .04, r = 0.201).

CONCLUSIONS

Penetration-aspiration occurs in dogs in the absence of respiratory CS (i.e., occult P-A). Dogs with pharyngeal weakness and EOR should be considered at risk for P-A.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.

Use of a videofluoroscopic feeding evaluation to guide management of dogs with congenital idiopathic megaoesophagus

Background

Evidence‐based guidelines for determining dietary management in dogs with megaoesophagus are lacking.

Objectives

This study looked to compare oesophageal clearance times (ECT) of liquid and two food consistencies using a contrast videofluoroscopy feeding evaluation, and to assess if recommendations made based on findings could improve regurgitation and quality of life in dogs with congenital megaoesophagus.

Methods

Twenty‐one dogs with congenital megaoesophagus and nine healthy dogs received liquid, slurry, and meatball diets containing barium while in an upright position. Follow‐up was performed to determine response to recommendations.

Results

Healthy dogs had significantly shorter median ECT for all consistencies (p < 0.001). In the megaoesophagus group, ECT varied by consistency and individual. The number of dogs in the megaoesophagus group with complete clearance was four (median ECT 10 min) for liquid, five (median ECT 5 min) for slurry, and two (median ECT 5 and 30 min, respectively) for meatballs. Partial clearance was seen in 11 dogs (median clearance 25%) with liquid, seven with slurry (median clearance 50%), and five with meatballs (median clearance 60%). Recommendations included altering current medications (13/21 dogs), diet consistency (6/21), time upright (12/21), water delivery (21/21), and adding activity (7/21). Regurgitation episodes/week decreased significantly from 5.5 to 2.5 (p < 0.001) at follow‐up 3–5 weeks post‐evaluation, with 95% of owners reporting improvement in quality of life. Seventy percent were alive 46–777 days after last recheck. Three dogs died from megaoesophagus associated complications (median survival 461 days after diagnosis).

Conclusions

The findings of this study suggest that a videofluoroscopic feeding evaluation may help guide management of dogs with congenital megaoesophagus.

Aerodigestive Disease in Dogs

Aerodigestive disorders (AeroDs) in people encompass a wide range of clinical syndromes, reflecting the complex relationship between the respiratory and digestive tracts. In veterinary medicine, aspiration is used interchangeably with aspiration pneumonia. Although aspiration pneumonia is a common disorder in dogs, it does not reflect the breadth of AeroDs. Unfortunately, AeroDs rarely are investigated in veterinary medicine because of lack of clinical recognition, limitations in available diagnostics, and the fact that AeroDs may be caused by occult digestive disease. Recognizing patients with AerodD represents an area of significant clinical importance that may provide additional areas of clinical intervention.

Videofluoroscopic swallow study features of lower esophageal sphincter achalasia-like syndrome in dogs

Background

Megaesophagus (ME) carries a poor long‐term prognosis in dogs. In people, lower esophageal sphincter (LES) disorders causing functional obstruction are rare causes of ME that may respond to targeted treatment. Functional LES disorders are reported rarely in dogs because of challenges in diagnostic methodologies.

Hypothesis/Objectives

To identify dogs with videofluoroscopic swallow study (VFSS) features of LES achalasia‐like syndrome (LES‐AS). We hypothesized that dogs with LES‐AS could be distinguished from normal dogs using standardized VFSS criteria.

Animals

Dogs with LES‐AS by VFSS (n = 19), healthy normal dogs (n = 20).

Methods

Retrospective study. One‐hundred thirty dogs presented to the University of Missouri Veterinary Health Center (MU‐VHC) between April 2015 and December 2017 for a free‐feeding VFSS; 20 healthy dogs were included as controls. Swallow studies were evaluated for failure of the LES to relax during pharyngeal swallow (LES‐AS). Affected dogs subsequently were evaluated using standardized criteria to identify metrics important for identifying and characterizing dogs with LES‐AS.

Results

Nineteen dogs with LES‐AS were identified out of 130 VFSS. Megaesophagus was present in 14 of 19 (73.7%) dogs with LES‐AS. A baseline esophageal fluid‐line and “bird beak” were present in 68.4% (95% confidence interval [CI], 47.5%‐89.3%) and 63.2% (95% CI, 41.5%‐84.8%) of affected dogs, respectively. The esophagus was graded as acontractile (8/19), hypomotile (8/19), or hypermotile (3/19).

Conclusions and Clinical Importance

Dogs with LES‐AS may successfully be identified by VFSS using a free‐feeding protocol. These data are of critical clinical importance because a subpopulation of dogs with functional LES obstruction may be candidates for targeted intervention.