Declaring Variables as static: Unexpected behaviour

I am developing a Java Spring project that uses Spring data.

It uses repositories to remove Dog Objects from a Kennel Object when the dog is collected by its owner.

Note that there can be multiple dogs associated with the one Kennel. There are also many kennels.

I have declared all my variables and methods as Static.

E.g:

static Kennel kennel;

dogsWithReleasedStatus;

static List<Dog> dogsWithReleasedStatus = new ArrayList<Dog>();

static List<Dog> allDogsInKennel = new ArrayList<Dog>();

Remove Method:

public static void removeDogFromKennel(int dogInKennel, List<Dog> allDogsInKennel) {
        //Loop through all dogs in the Kennel
        for (dogInKennel = 0; dogInKennel < allDogsInKennel.size(); dogInKennel++) {

            if (allDogsInKennel.get(dogInKennel).getStatus() == dogStatus.RELEASED) {

                kennel.removeDog(allDogsInKennel.get(dogInKennel));

                dogInKennel--;


            }
        }
    }

Calling remove method in the main:

(note getAllKennelIds() just returns a list of kennel Ids as strings ):

List<String> kennelIdsToloopThrough = getAllKennelIds();

 for (int i = 0; i < kennelIdsToloopThrough.size(); i++) {

 //create list with all dogs in kennels 
 allDogsInKennel = kennel.getDogsList();

 //pass list and remove dog from kennel if status = released
 removeDogFromKennel(i,allDogsInKennel);

 //save the changes to the DB
 kennelRepository.save(kennel);

 }

The issue I am having is that when the save method is called, it is deleting ALL the dogs in kennels, not just those with a "released" status.

What am I doing wrong?