BACKGROUND: In humans, there is a high prevalence of postinfectious irritable bowel syndrome (IBS) after acute giardiasis. OBJECTIVE: To evaluate the prevalence of chronic gastrointestinal and dermatologic signs in dogs after acute Giardia-associated gastroenteritis. ANIMALS: Forty-nine dogs with acute gastroenteritis and confirmed Giardia infection and fifty control dogs without a history of acute giardiasis. METHODS: Retrospective longitudinal study. Data were collected from dogs with acute gastrointestinal signs and confirmed Giardia infection at a young age (< 9 months) and from healthy controls matched by breed, sex, and age. After a minimum follow-up period of 12 months, dog owners completed a questionnaire assessing chronic gastrointestinal and dermatologic signs later in life. Severity of chronic disease was quantified using a modified canine inflammatory bowel disease activity index (CIBDAI). Univariable logistic regression was used to compare frequencies of chronic signs between groups. RESULTS: Dogs with acute giardiasis at a young age had a higher prevalence of chronic intestinal signs (Giardia 29%, 14/49; controls 10%, 5/50; p = 0.03) and pruritus (Giardia 33%, 16/49; controls 8%, 4/50; p = 0.01) later in life than did control dogs. A high canine acute diarrhea severity (CADS) index during acute enteritis, combined with metronidazole treatment, increased the risk of developing chronic gastrointestinal signs (p = 0.04). CONCLUSION AND CLINICAL IMPORTANCE: Juvenile dogs with acute gastroenteritis and confirmed Giardia infection had a higher prevalence of pruritus and chronic gastrointestinal signs. Severe enteritis and metronidazole administration may increase the risk of developing chronic gastrointestinal signs.