diff --git a/src/app/service/image/image.service_test.go b/src/app/service/image/image.service_test.go
index 4d7e029..2a2138d 100644
--- a/src/app/service/image/image.service_test.go
+++ b/src/app/service/image/image.service_test.go
@@ -1,21 +1,30 @@
 package image
 
 import (
+	"net/http"
 	"testing"
 
 	"github.com/bxcodec/faker/v4"
 	"github.com/google/uuid"
+	"github.com/isd-sgcu/johnjud-gateway/src/app/constant"
+	"github.com/isd-sgcu/johnjud-gateway/src/app/dto"
 	utils "github.com/isd-sgcu/johnjud-gateway/src/app/utils/image"
 	imageMock "github.com/isd-sgcu/johnjud-gateway/src/mocks/client/image"
 	imageProto "github.com/isd-sgcu/johnjud-go-proto/johnjud/file/image/v1"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/suite"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 type ImageServiceTest struct {
 	suite.Suite
 	Images []*imageProto.Image
 	PetId  uuid.UUID
+
+	NotFoundErr           *dto.ResponseErr
+	UnavailableServiceErr *dto.ResponseErr
+	InternalErr           *dto.ResponseErr
 }
 
 func TestImageService(t *testing.T) {
@@ -47,6 +56,22 @@ func (t *ImageServiceTest) SetupTest() {
 			ObjectKey: faker.Word(),
 		},
 	}
+
+	t.NotFoundErr = &dto.ResponseErr{
+		StatusCode: http.StatusNotFound,
+		Message:    constant.PetNotFoundMessage,
+		Data:       nil,
+	}
+	t.UnavailableServiceErr = &dto.ResponseErr{
+		StatusCode: http.StatusServiceUnavailable,
+		Message:    constant.UnavailableServiceMessage,
+		Data:       nil,
+	}
+	t.InternalErr = &dto.ResponseErr{
+		StatusCode: http.StatusInternalServerError,
+		Message:    constant.InternalErrorMessage,
+		Data:       nil,
+	}
 }
 
 func (t *ImageServiceTest) TestFindByPetIdSuccess() {
@@ -68,3 +93,60 @@ func (t *ImageServiceTest) TestFindByPetIdSuccess() {
 	assert.Nil(t.T(), err)
 	assert.Equal(t.T(), expected, actual)
 }
+
+func (t *ImageServiceTest) TestFindByPetIdNotFoundError() {
+	protoReq := &imageProto.FindImageByPetIdRequest{
+		PetId: t.PetId.String(),
+	}
+
+	clientErr := status.Error(codes.NotFound, constant.PetNotFoundMessage)
+
+	expected := t.NotFoundErr
+
+	client := imageMock.ImageClientMock{}
+	client.On("FindByPetId", protoReq).Return(nil, clientErr)
+
+	svc := NewService(&client)
+	actual, err := svc.FindByPetId(t.PetId.String())
+
+	assert.Nil(t.T(), actual)
+	assert.Equal(t.T(), expected, err)
+}
+
+func (t *ImageServiceTest) TestFindByPetIdUnavailableServiceError() {
+	protoReq := &imageProto.FindImageByPetIdRequest{
+		PetId: t.PetId.String(),
+	}
+
+	clientErr := status.Error(codes.Unavailable, constant.UnavailableServiceMessage)
+
+	expected := t.UnavailableServiceErr
+
+	client := imageMock.ImageClientMock{}
+	client.On("FindByPetId", protoReq).Return(nil, clientErr)
+
+	svc := NewService(&client)
+	actual, err := svc.FindByPetId(t.PetId.String())
+
+	assert.Nil(t.T(), actual)
+	assert.Equal(t.T(), expected, err)
+}
+
+func (t *ImageServiceTest) TestFindByPetIdInternalError() {
+	protoReq := &imageProto.FindImageByPetIdRequest{
+		PetId: t.PetId.String(),
+	}
+
+	clientErr := status.Error(codes.Internal, constant.InternalErrorMessage)
+
+	expected := t.InternalErr
+
+	client := imageMock.ImageClientMock{}
+	client.On("FindByPetId", protoReq).Return(nil, clientErr)
+
+	svc := NewService(&client)
+	actual, err := svc.FindByPetId(t.PetId.String())
+
+	assert.Nil(t.T(), actual)
+	assert.Equal(t.T(), expected, err)
+}