Anheuser-Busch (BUD -0.87%) gave investors their first detailed glimpse into how the COVID-19 pandemic is impacting its business on Thursday.

The beer giant said sales volumes were trending modestly higher through February but then slumped as social distancing efforts eliminated a key revenue source. Volumes fell 9% for the first quarter, which runs through late March, and then declined 32% in April due to the lack of on-premise drinking occasions at places like bars, clubs, restaurants, sporting events, and concerts.

A man shopping for beer at the grocery store.

Image source: Getty Images.

There were some bright spots in the report, including the successful launch of Bud Light Seltzer, InBev's answer to booming demand for hard seltzer products and dropping popularity of light beers. The company also gained market share in Europe before sales restrictions swamped its momentum.

Trends will get worse before they get better, executives warned. "We expect that the impact on our [second quarter] results will be materially worse than in [the first quarter]," management said in a press release.

Yet the alcoholic beverage giant is encouraged by the quick rebound it has seen in the China market, which was the first to be impacted by the virus. Sales declines improved to 17% in April from a 47% decline in the previous three-month period.