Is This A Message?

My dog, Abbie, was euthanized over three years ago. At first I kept seeing her in my dreams, it was rather unsurprising, I had her since I was around 4/5, so obviously I was greatly attached to her. The only somewhat peculiar thing was that in my dreams she was always a ghost. I never once had a dream where she was alive, only that she was coming to visit me. However, a few weeks after she passed, my family and I began hearing the sound of a dog walking across the floor and coming into our rooms, we have two other dogs but they stay in the kitchen at night. The first few times I put it down to my imagination, I missed my dog greatly and I wanted her to really be there, but as the weeks progressed it became more and more prominent. Even now three years on, we can sometimes still her the sound of a dog walking across the floor, with no other explanation, but I digress.

Yesterday, on the 13th of March, which was my birthday, I had a dream about my Abbie and the older of my two remaining dogs, Zoe, being in my room at university. It felt highly realistic, but the window in my university room led to my garden at home, which is where my dog was buried. I hadn't had a dream about Abbie in many weeks, but she wasn't really to focus of my dream, the real focus was on my older dog Zoe. It would make sense for me to dream about Zoe, since she was a present for my fourth birthday. However, I felt that something wasn't right in my dream, my other dog Max, wasn't there, which is what I don't understand, why was I dreaming about Abbie and Zoe, while leaving out Max. In the dream I clearly remember stopping Zoe from following Abbie out into the garden and then I woke up, with a sense of both peace and dread.

At first I put it down to the fact that it could be some form of memory from childhood, since it was my birthday and I am away from home, however I don't believe that's the case. Zoe is 15 years old and is going to be 16 this year, and I can't help wondering if this may have been a sign that she is ready to pass and rather than stopping her (as I did in my dream), that maybe I should be prepared to let her go. I'd like to think that it was just a normal dream and it didn't mean anything, but I can't shake this feeling that something is wrong.