What is a component of the gastrointestinal exam?

The option related to the gastrointestinal exam is the rectal exam. This component is essential for assessing the health of a dog's gastrointestinal tract as it allows the veterinarian to evaluate several important factors. During a rectal examination, a vet can check for abnormalities such as fecal impaction, masses, or signs of disease in structures like the anal glands, intestines, and other organs within the pelvic region.

This examination can reveal vital information about a dog’s bowel health and overall gastrointestinal function. It is a critical part of a comprehensive gastrointestinal assessment, as it provides direct insight into the rectal and anal health which can affect digestion and general health.

The other options do not pertain directly to the gastrointestinal system. Heart auscultation is focused on the cardiovascular system, skin palpation assesses dermatological health, and joint flexibility checks evaluate musculoskeletal health. Each of these components is important in their respective examinations but does not specifically address the gastrointestinal tract.