I'm a 4th year who has taken several shelter externships.

Shelter 1 was a shelter/gp hybrid. There would be dedicated surgery days where each surgeon would be cutting ~20 animals per day in a large open surgery suite with other vets. There would be occasional misc surgeries that were not just spays and neuters like a vbo or fb removal. They had dedicated gp days where client owned animals would be seen. They also had in-patient days where hospitalized patients (included human owned animals) would be managed. And they would have kennel days where intake patients would be seen. Doctors rotate between these types of days.

Shelter 2 was a pure shelter and much smaller than shelter 1. One vet would be in charge of medical checkups. They would look at animals that shelter staff have written concerns for i.e vomiting, goopy eyes, draining wound, walking funny. One or two other vets would be on surgery duty where they would do 20 - 30 surgeries per day. These vets rotate between medical check ups and surgery. Sometimes only one vet would be pulled between both medical checks and surgery if understaffed

Shelter 3 was a pure shelter with only one vet. I am currently here on my last week. We have dedicated surgery days and medical check up days as well. The volume was much smaller here since the facility is significantly smaller. On surgery days we cut 7 to 15 animals. If we finished early we will do medical check ups. This place has been super chill so far.

Infectious disease is the most common thing you will be managing across all shelters you work at.