A challenging case: Acute-on-chronic vomiting in a German shepherd - Veterinary Medicine
  • SEARCH:
Medicine Center
DVM Veterinary Medicine Featuring Information from:

ADVERTISEMENT

A challenging case: Acute-on-chronic vomiting in a German shepherd
These clinicians discover that this dog's history of chronic vomiting was disguising a serious underlying problem.


VETERINARY MEDICINE


Initial therapy includes correcting fluid and electrolyte abnormalities. If indicated, initial therapy may also include antibiotics and analgesics. Once gastroesophageal intussusception is diagnosed, immediate surgical correction is required. Reduce the stomach invagination, and assess affected organs for viability (i.e. observe serosal color, wall texture, vascular patency, and presence of motility). Necrotic tissue can range in color from green to black, will often feel thin, may lack peristaltic activity, and, if incised, may not display normal bleeding. If you are unsure about the viability of a portion of the stomach, remove or invaginate it.8 Also secure the stomach with a gastropexy so that it will stay within the abdominal cavity. Incisional, belt-loop, and circumcostal gastropexies can prevent recurrence of invagination.2-5 In some cases, it may be beneficial to perform more than one gastropexy—more specifically, one on the left body wall with the idea that the esophageal hiatus is to the left of midline, so securing the stomach in this manner will have an advantage over right-sided gastropexies.2,4 Fundoplication or alteration of the esophageal hiatus are other methods that may prevent recurrence.2,5,7 Fundoplication involves apposing the fundus of the stomach to the esophagus, and alteration of the hiatus involves narrowing the hiatus. These procedures are not routinely performed and may have negative effects in patients with megaesophagus by creating more resistance for food to pass easily into the stomach.

After surgical correction, most patients require management of their megaesophagus-related sequelae and esophageal and gastric mucosal damage. If aspiration pneumonia is present, administer appropriate antibiotics based on bacterial culture and antimicrobial sensitivity testing results or a good empirical selection until the patient is stable enough to obtain a sample by transtracheal wash. Nasal oxygen and nebulization may also be indicated.2 In patients with evidence of severe esophagitis and gastritis, placing a feeding tube such as a jejunostomy tube will allow the esophageal and gastric mucosa time to rest and provide a method of supplying nutrients to the patient. Administering H2 receptor blockers and other mucosal protectants will also aid in mucosal healing.3 Dogs with megaesophagus should be fed small frequent meals while being held in an upright position to facilitate passage of ingesta into the stomach.

The prognosis in dogs with gastroesophageal intussusception is typically guarded to poor. A review of literature published in 1984 revealed a mortality rate of 95%.3 An unfavorable prognosis is most likely attributable to the fact that this is a relatively rare condition with limited awareness, resulting in delayed or incorrect diagnosis; that death can occur rapidly after clinical signs appear; and that secondary complications such as aspiration pneumonia can mask a correct diagnosis and worsen the prognosis.3

This case was challenging because an early diagnosis of esophageal disease was hindered by the dog's history of chronic vomiting, allowing the eventual development of a severe condition with an unfavorable outcome. The cause of the vomiting, or the vomiting itself, could have been a predisposing factor for the development of gastroesophageal intussusception in this dog, as people with a history of physical exertion and peptic disease are predisposed to gastroesophageal intussusception.9 It is reasonable to speculate that this dog's history of chronic vomiting may have also involved chronic regurgitation.

It is important to differentiate between vomiting and regurgitation because they can result from vastly different disease processes. This differentiation can be accomplished by taking a detailed history and performing a complete physical examination. Regurgitation is not preceded by signs of nausea or retching (forceful contraction of abdominal muscles), the regurgitated material should not contain bile, and, if the material is pH-tested, it should have a value of 7 or higher. Further diagnostic tests to rule out regurgitation may include radiography (plain and contrast) and endoscopy.

The exact cause of this dog's megaesophagus was unknown, but it is likely that the megaesophagus was present before the gastroesophageal intussusception. Initial abdominal radiographs of this dog were not available for viewing. They may have been considered to be normal because the caudal thorax may not have been included in the study, the lack of the gastric gas bubble in the cranial abdomen may have been overlooked, or the gastroesophageal intussusception was possibly not present at that time. The rarity of this condition and a generalized low level of awareness may have allowed this condition to persist for up to 24 hours before the proper diagnosis was made and appropriate treatment was initiated. The focus on the history of vomiting and not considering esophageal disease undoubtedly had a negative effect on the eventual outcome.


ADVERTISEMENT

Source: VETERINARY MEDICINE,
Click here