Erd

Attached is my ERD that I'm working on for my Oracle class. It is for an animal shelter. I was wondering whether anyone could give me feedback on the design.

Thanks.



Assumptions:

* Animals stay in their shelter until adoption.
* A person may donate multiple animals and adopt multiple animals.
* A person may give several donations.
* A person may receive several thank you cards for his or her adoptions.
* A person may return an animal that they adopted.
* A person cannot adopt and return an animal and later adopt the same animal again.
* An animal must be donated by one and only one person.
* An animal may change cages temporarily.
* An animal may receive the same medical procedure multiple times.
* An animal can receive care from more than one physician.
* An animal does not have a last name.
* Each animal shelter has more than one animal.
* Each piece of medical history of an animal is done by one and only one doctor.