GI stasis is one the most common health issues in pet rabbits and often occurs secondary to an underlying medical issue.1 With the exception of physiologic ileus (eg, from a low-fiber diet), common primary problems that occur with GI stasis include gastric dilation and GI obstruction, typically of either the pylorus or duodenum. In most cases, a small ingested hair pellet is the cause of the intestinal obstruction.2 Stomach outflow obstruction can lead to caudal vena cava compression, cranial displacement of the diaphragm, activation of the sympathetic nervous system, severe pain, and reduced respiratory lung volume and heart preload. If the stomach outflow obstruction is left untreated, the pathophysiologic changes continue to worsen, leading to debilitating pain, hypovolemia, hypotension, hypothermia, disseminated intravascular coagulation, and acidosis.3-9
In addition to diagnostic imaging, clinical pathology (ie, CBC, serum chemistry profile, blood gas analysis) is important for determining a patient’s health status.3-11 For example, hyponatremia is considered a negative prognostic factor,4 and severe hyperglycemia can occur due to severe pain and stress, which can affect treatment and management decisions.5 As in other species with severe GI disturbances, blood gas analysis and acid-base status can be useful in determining appropriate treatment.
In this study of pet rabbits with gastric dilation and suspected obstruction, the authors evaluated acid-base status, electrolytes, and blood gas values, as well as how both time of presentation and therapy influenced these parameters. Prospective data from 30 rabbits were included. The resulting data suggest that acid-base balance disturbances due to gastric dilation can worsen over time without treatment. Specifically, partial pressure of carbon dioxide, partial pressure of bicarbonate, and base excess were significantly lower in rabbits presented 12 hours after the owner first noticed signs of illness as compared with rabbits presented within 6 hours. These findings strongly suggest the need for immediate veterinary care in rabbits showing reduced activity, dysphagia, and changes in fecal output.