I'm a shift worker. I had called out sick once and then called out again about a week after that. Manager pulled me into the room to warn me about my sick calls because they can see when staff has stretches of days off in a row for vacation. I was not in vacation. I look Manager dead in the eye and said I called out because my pet is undergoing treatment for an illness and did not respond well to the treatment. Manager's response was “aww I'm sorry” and proceeded to warn me that “staffing” looks for patterns and I could end up on the watch list. A watch list that I'm sure the managers puts people on.
Other coworkers who have actually called out “sick” prior to vacations or after vacations have yet to be warned and at least one of them is in negative sick hours.
The irony, all this happens right after the Manager hands out “appreciation” gifts from the company.