Create a comprehensive case study for third-year veterinary students about a 7-year-old Golden Retriever presenting with acute vomiting and lethargy.

Include:

• Complete signalment and presenting complaint

• Detailed history (duration, progression, owner observations)

• Physical examination findings (normal and abnormal)

• Initial diagnostic plan with rationale

• 3-4 reasonable differential diagnoses ranked by likelihood

• Follow-up questions that test clinical reasoning

Format as a progressive disclosure case where information is revealed step-by-step. Use realistic clinical details that mirror actual practice scenarios.

Goal: Help students practice systematic diagnostic approaches and clinical decision-making for common GI emergencies.