Possible null reference return.

Cannot convert null literal to non-nullable reference type.

Possible null reference argument for parameter 'expression' in 'MemberExpression Expression.Property(Expression expression, string propertyName)'.

Define a constant instead of using this literal 'Tutor' 4 times. (https://rules.sonarsource.com/csharp/RSPEC-1192)

Define a constant instead of using this literal 'datetime' 5 times. (https://rules.sonarsource.com/csharp/RSPEC-1192)

Define a constant instead of using this literal 'Cachorro' 6 times. (https://rules.sonarsource.com/csharp/RSPEC-1192)

Annotate this method with ProducesResponseType containing the return type for successful responses. (https://rules.sonarsource.com/csharp/RSPEC-6968)

This controller has multiple responsibilities and could be split into 3 smaller controllers. (https://rules.sonarsource.com/csharp/RSPEC-6960)

Possible null reference return.