Several alternative therapies are attracting attention for successfully treating megaesophagus, either as a sole therapy or part of a larger treatment approach.

Megaesophagus is a disorder of the esophagus in mammals. It’s characterized by esophageal dilatation and an inability of the esophagus to effectively transport food from the throat to the stomach. Megaesophagus occurs predominately in humans and dogs, and is the most common cause of canine regurgitation. Any dog breed can be affected, but certain underlying conditions have breed predilections.¹ Experts in general agree that dogs with megaesophagus carry a poor prognosis as they typically die of malnutrition, aspiration pneumonia, or are euthanized because the owners are told there is no hope.²

Pathophysiology of the esophagus

Dysphagia, or disorder of swallowing, is a major sign of esophageal disease. Swallowing is a complex and highly coordinated physical act that can be divided into three phases: oral, pharyngeal and esophageal.³ The oral phase is usually associated with lesions of the oral cavity and tongue, while the pharyngeal phase is associated with pharyngitis and tonsillitis. When considering the esophageal phase, the first and last part may be impeded by failure of the cricopharyngeus muscle to relax during swallowing (achalasia), or increased tension at the lower esophageal sphincter which impedes the flow of food into the stomach.^1,3

Segmental or diffuse dysfunction of the body of the esophagus is classified as megaesophagus. It results from atony of the esophageal muscle and is characterized by flaccidity and luminal dilatation. The esophagus is innervated by the vagus nerve; afferent vagal receptors are stimulated by the presence of food and liquid in the pharynx and upper esophagus, causing a swallow reflex and the esophagus to contract.¹ The functional lesion may reside in the upper motor neurons of the central swallowing center or in the afferent sensory arm of the reflex controlling peristalsis, which arises in the esophagus.³

Whatever the etiology, the result is failure of the peristaltic propulsion of the food bolus through the lower esophageal sphincter. Retention of food in the esophagus leads to putrefaction and esophagitis in dilated/dependent areas. The volume of the dilated thoracic and cervical esophagus may greatly exceed that of the stomach, with displacement of the intrathoracic trachea and heart ventrally. Common signs animals may present include malnutrition, dehydration, rhinitis and aspiration pneumonia.^1,3,4,5

Clinical aspects of megaesophagus

There are two primary categories of megaesophagus — congenital and acquired.

Congenital megaesophagus: In the congenital form of the disease, swallowing dysfunction and regurgitation becomes especially evident with the introduction of solid food.^1,3,4 A puppy with congenital megaesophagus characteristically begins to regurgitate at weaning (eight to 12 weeks old) when he is consistently consuming solid food.⁴ Initially, the puppy regurgitates immediately after food consumption, but as the esophagus dilates, food is held for longer periods before regurgitation. Commonly, the puppy will present with fever, cough and nasal discharge along with poor weight gain as the syndrome becomes complicated by aspiration pneumonia.⁴

Congenital megaesophagus is primarily associated with heritable anomalies in either neuromuscular innervation or vascular ring anomalies that entrap the esophagus near the heart base. Prognosis for the resolution of congenital megaesophagus in puppies is only 20% to 40%, although there is potential for improvement up to one year of age.^1,6

Acquired megaesophagus: Gastrointestinal, endocrine, immune-mediated, neuromuscular, paraneoplastic and toxic disorders have been associated with acquired megaesophagus, with myasthenia gravis being the most common etiology in 25% to 30% of cases.^1,5 Affected animals regurgitate (lack of vigorous abdominal contractions, vomitus with PH>5, lacks bilirubin) and have generally lost weight.⁶ Respiratory signs may predominate with little or no history of regurgitation. Thoracic radiographs reveal air, fluid or food in a dilated esophagus.^1,4 Typical treatment involves medical management directed at the etiology, or surgery for vascular ring anomalies. This includes finding a diet that best prevents regurgitation, and this varies between individuals (slurry to more solid). A feeding schedule of small frequent meals from an elevated dish, where the forelimbs are higher than the hindlimbs, along with keeping the dog in this upright position ten to 15 minutes after eating, works best to prevent postprandial regurgitation. The overall prognosis is poor if the underlying etiology cannot be corrected, and many affected animals die from aspiration pneumonia.⁴

Alternative approaches to megaesophagus

The morbidity and mortality of dogs affected with megaesophagus depends on the degree and nature of the underlying disease (if known), as well as client compliance. Medical management in general is aimed at relieving clinical signs, such as weight loss and respiratory infections secondary to food aspiration. Alternative therapies are increasingly being used to stimulate the esophagus to move more effectively, either as a sole therapy in mild cases or as an adjunct to Western therapeutic management.^7-10

Some promising evidence-based clinical studies demonstrate the efficacy of acupoint stimulation on gastrointestinal motility. Studies have focused on two key acupuncture points — PC-6 and ST-36. Research on PC-6 includes 33 controlled trials (published worldwide as of 1996) for its use for nausea and vomiting, with 27/29 trials showing statistically significant positive results. Stimulating Pericardium 6 (PC-6) in clinical trials produced a significant reduction of perioperative emetic sequelae.

ST-36 has been found to have analgesic and spasmolytic effects on the GI tract; it also regulates gastric acidity and has a homeostatic effect in endocrine and metabolic disorders.^9,10 

Other studies have demonstrated that transcutaneous electrical stimulation (TENS) at LI-4 and SI-3/HT-7 significantly decreased lower esophageal sphincter pressure in humans with achalasia, by creating an increased plasma vasoactive intestinal peptide release. This inhibitory neuropeptide is associated with the relaxation of lower esophageal sphincters.⁹

Other alternative approaches used successfully in treating megaesophagus include Traditional Chinese Veterinary Medicine (TCVM), homeopathy and laser therapy.

TCVM and acupuncture

In TCVM, megaesophagus is considered a Qi Deficiency, due to the inhibition of directional movement of a tubular organ. It can be also be associated with concurrent Blood or Yin Deficiency with subsequent dryness that fails to lubricate the ingesta. With acquired megaesophagus, an exogenous (i.e. distemper virus, trauma, toxins) or endogenous (i.e. hypothyroidism, hypoadrenocorticism, myasthenia gravis) pernicious influence leading to a localized Wei syndrome (weakness without pain) needs to be considered, and the pattern of imbalance addressed. The primary treatment principles are to tonify global and local Qi, assist directional Qi flow, increase body moisture/fluids, tonify Yin, and nourish and invigorate blood.⁸

Various acupoint prescriptions for this condition have been presented depending on the TCVM pattern diagnosis as well as results from evidence-based studies. Acupuncture has demonstrated efficacy in the control of vomiting (Stomach Qi rebelling) associated with megaesophagus. In one study on five dogs with idiopathic megaesophagus, a 70% resolution of regurgitation along with increased weight gain was observed when using points PC-6, PC-9, HT-9, ST-36, LI-4, LI-11 and ST-40 with dry needles for ten minutes twice a week for four weeks.^8,9,10 Other experts have provided acupoint prescriptions such as LI-4/11, ST-36/41, BL-13/23, PC-6 and HT-9 as beneficial for treating megaesophagus.¹¹ Acupoint selection can also be based on treatment principles and TCVM patterns with Local Points (GB 20/21, TH-17/16, ST-9/10, LI-17/18, CV-22/23) along with Distal Points (LI-4/11, SI-3, LU-7, LIV-3) and Qi Tonifying Points (BL-20/21, BL 23/26, Shen-shu, ST-36, SP-9). Electro-acupuncture is also used with success in this condition, with treatments combining CV-23+CV-22, LI-17+GB-21, BL-14 bilateral, BL-20 bilateral, BL-23 bilateral (20Hz/10 min + 80/120 Hz 10 min).¹²

Chinese herbal medicine as a component of traditional Chinese Veterinary Medicine is used to address the root of the megaesophagus disease syndrome, Qi deficiency, as well as other imbalances such as Yin and Blood Deficiency. Chinese herbal formulas such as Four Gentlemen^a (modified Si Jun Zi Tang) for Qi deficiency and/or Happy Earth^a (modified Wei Chang He) for rebellious Stomach Qi (regurgitation) in combination with acupuncture can be used successfully to treat megaesophagus. Pharmaceutical studies demonstrating improved gastric emptying and small intestinal motility by inhibiting the dopamine D receptor and 5-HT receptor as well as improvement in overall health in animal subjects has been demonstrated for Si Jun Zi Tang.^{13, 14, 15} Components of the herbal formula Happy Earth have demonstrated specific and significant effects on the gastrointestinal tract such as inhibition of the vomiting center in the brain and anti-spasmodic effects of the small intestine through modulation of the central nervous system.^{15, 16, 17}

Homeopathy

Homeopathy is an individualized therapeutic approach based on the principles that the same illness creates a different set of clinical signs in different individuals.¹⁸ Selection of homeopathic remedies follows the medical principles first espoused by Hippocrates – “Like cures like”, known as the “Law of Similars”. Homeopathic medicine has no formal experimental studies on efficacy associated with treatment of megaesophagus. Clinical evidence shows good results using classical homeopathy to find the “similimum” – the homeopathic medicine that matches the individual animal’s clinical signs associated with the disease condition as well as with general characteristics.

Laser

Low-level laser therapy (LLLT) is a therapeutic modality of photobiostimulation that uses the emission of red and near infrared light wavelengths between 400 nm and 905 nm that are optimally absorbed by mitochondrial chromophores (cytochrome C oxidase). This sets up a cascade of events, including upregulated oxidative phosphorylation and increased ATP production, that modulates the activity of a number of cell types and biological mechanisms. In addition to wavelength and power (measured in watts or miliwatts), various frequencies (ranging from 4 Hz to over 10,000 Hz) are used depending on the tissue type and disease condition being treated. It is imperative to know the power (watts) and wavelength (nm) of the laser device being used in order to apply it appropriately to tissues and not cause harm. Some lasers (Class 4) generate thermal changes to tissues that can be tolerated in musculoskeletal issues, but are contraindicated over endocrine and gonads.

The laser system used in the case report on page xx was a Class 2 visible light wavelength (635 nm, 405 nm) frequency specific low power (5 mW, 7.5 mW) laser. The end result is that laser therapy, when used appropriately, with an understanding of the specifications and applications, can provide a non-invasive, pain-free, drug-free and non-surgical treatment for a variety of conditions.

Conclusion

Megaesophagus is a debilitating condition that carries a poor prognosis, whether present congenitally or as an acquired condition in adult dogs. Chronic regurgitation accompanied by aspiration pneumonia leaves an affected animal malnourished and in neverending cycles of severe respiratory distress. Several alternative therapies are beginning to attract attention for successfully treating this condition, either as a sole therapy or a part of a larger integrative medicine approach. As these therapies become more mainstream for the approach of megaesophagus treatment, there is cautious optimism that in some cases the condition could be successfully managed with a good quality of life for the affected animal.

Using acupuncture for megaesophagus

Case #1

A four-month-old intact female five-pound Bichon Frise/Havanese crossbreed was presented to the Integrative Medicine Service with a diagnosis of megaesophagus. The puppy had a history of chronic vomiting after eating (one to two times a day) and a failure to gain weight since weaning. Conventional treatment resulted in no improvement.

TCVM with needles and the Chinese herb Happy Earth (modified Wei Chang He) was started. The one-week recheck showed significant clinical improvement, and after three needle treatments and after nine months of Happy Earth, the pup was at a normal weight and asymptomatic. She was still fine at four years of age.

Case #2

A two-year-old male neutered Siberian Husky crossbreed was presented to the emergency and critical care clinic at the Veterinary Teaching Hospital, with a several-week history of vomiting and gagging along with rapidly deteriorating locomotor activity. The dog had been normal prior to a vaccination one week before. With conventional treatment, the dog then developed severe hindquarter weakness and was diagnosed with lower motor neuron disease and referred to the teaching hospital. A diagnosis of presumptive acquired myasthenia gravis of undetermined etiology was made.

The dog responded to treatment with a gradual improvement of weakness and decreased regurgitation. Three weeks after the diagnosis, the owner presented her dog to the Integrative Medicine Service for assessment; the goal was to decrease Western medications, which were creating side effects such as ravenous appetite, diarrhea and lethargy, and possible improvement of the megaesophagus.

Treatment included dry needle acupuncture and two herbal formulas, Four Gentlemen (to tonify Qi) and concentrated Hindquarter Weakness (to address Qi and Yin Deficiency), with no change in Western drug doses and continued feeding in the Bailey chair. The protein in the dog’s diet was changed from chicken (Hot) to beef (Slight Warm) for a slightly Cooler diet. Two weeks later, at recheck, there was significant improvement with a good appetite, no regurgitation and conscious proprioception normal in one hind leg.

Over the next two months, with acupuncture treatment monthly, all Western medications were tapered and then stopped while the dog returned to a normal neurological status and energy level with no regurgitation. He continues to do well at seven months past initial clinical signs.

Using homeopathy for megaesophagus

From Ed DeBeukelaer, MVRCS, author of Homeopathy: What to Expect, Including 101 Cured Cases (12edb3@gmail.com)

Two Dalmatian puppies were seen at three weeks of age for milk regurgitation, but were otherwise clinically normal. By five weeks of age, a full diagnostic workup was performed due to increasing dyspnea, yielding a diagnosis of megaesophagus with copious aspiration of milk into the lungs.

Phosphorus 30c (tid drops) was started while the owner contemplated whether to continue clinical treatment or euthanize the puppies. The following day, there was a steady improvement in their breathing, accompanied by decreased regurgitation; therefore, treatment was continued.

At eight months old, one of the puppies was euthanized due to continued clinical complications. The second puppy is now 2.5 years old, has steadily grown and is taller than her normal littermates. She still regurgitates small amounts of smelly mucus every day but is able to maintain normal nutritional status, with only minor intermittent loss of small amounts of ingesta.

She has responded well to the homeopathic medicine Falcon Peregrine (made from Peregrine Falcon) for abdominal enlargement after eating. A year later Ara macau (made from Scarlet Macaw) was prescribed because of her character, mild regurgitation and mild otitis. The ear problem resolved, and she has since taken this remedy every few months in a 30c preparation when the regurgitation increases.

Using laser for megaesophagus

From Janet Gordon Palm, DVM, CVCP (animobilityvet.com)

An 11-year-old male neutered Collie presented at New Hope Animal Hospital with evidence of aspiration pneumonia secondary to megaesophagus. The dog had a history of regurgitation and retching multiple times as day for months, and now presented with worsening pneumonia, which had been present for over one week. Radiographs were taken, and a broad-spectrum antibiotic therapy, which included Clavamox and Baytril, was initiated.

One week later, the dog presented for recheck. He had not significantly improved and the owner had to go on an international trip. Due to the dog’s deteriorating condition, he was boarded at the veterinary clinic. While at the clinic, the megaesophagus was treated with laser therapy twice daily for two days. On the second day of treatment, the dog was brighter and eating without retching. A total of six treatments were performed over a one-week period. The pneumonia resolved quickly once laser therapy was started, and the dog was relatively cough- and regurgitation-free during the rest of the time he was boarded.

The owner was unable to afford the remainder of the recommended 12 total treatments (twice a week for two weeks, followed by once a week for eight sessions). The dog was discharged, and was symptom-free for over five weeks. He then presented with a recurrence of occasional regurgitation, but no further aspiration. Laser treatment was reinstated and the dog was successfully managed with this therapy until euthanasia seven years later, due to unassociated age-related quality of life issues.

______________________________________________________________________

Footnotes

^a Veterinary specific patented herbal formula; Jing Tang Herbal, Reddick, FL. USA

References

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⁴Merck- Aiello S, Mays A (eds).  Anomalies of the Digestive System and Diseases of the Esophagus in Small Animals. In: The Merck Veterinary Manual 8^th Ed, Whitehouse Station, NJ; Merck & Co Inc 1998:128, 276-278.

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