He’s nil by mouth but that doesn’t stop him attacking the treats

My dog doesn’t understand the word cancer – and I have to remain upbeat as he can pick up on sadness. It’s not easy – I’ve tried to find a support group. I’ve found Dignipets, which sounds like a dog version of Dignitas. I’m holding it together but tears are streaming down my face. How am I going to cope?

Muggles and I are off to visit the oncologist. I’m imagining us sitting opposite a doctor at an oak-panelled desk, but when we get there, I realise it’s less formal. I’m carrying a one of my sweatshirts in a bag to leave there for him to smell. At least he can feel that I’m close to him when I can’t be there. Will they give him a special gown to wear? Can I hold his paw when he comes round from the anaesthetic?

I save all these questions for the oncologist. I wonder if other people ask these sorts of questions – or am I the only one feeling like this? I know he’s not human but he is my dog.

Thank god I have pet insurance: I’m told the removal of the lump on his back with ultrasound to check it hasn’t spread will cost £2,700. I had been looking online at the best place to take him. I found a big cancer unit in Guildford with posh chemotherapy suites and a waiting room with big orange and blue coloured armchairs. It looked more like the private hospital my mum went to with bowel cancer, than a clinic for cats and dogs. But I go with my gut instinct and choose the local vet – it feels less clinical and is far more practical.

When Muggles and I are ushered into the oncologists room, I realise it's a drop-off and pick-up situation. I’ve got to leave my emotions at the front door. It’s going to be hard to leave him. He’s glued to my leg: yes, he definitely knows something is up when he moves to sit by the door. Is he hoping to make a last-minute escape?

He is nil by mouth but when he claps eyes on a glass bowl of doggy treats beside the vet he suddenly, to my horror, lurches at them. The vet prizes open his mouth and retrieves them; his hand escapes with has just a few toothmark indentations.

I can tell that they are politely trying to get rid of me. “Try not to worry, he’s in good hands.”

I’m told he has a whole kennel to himself and his closest neighbour is another golden retriever, called Beleza. She must Spanish, I think. The name sounds exotic. I realise my mind is drifting off when I visualise giving Muggles away at his wedding and wonder what his puppies might look like – if I hadn’t castrated him, that is. All this fantasising is easier than facing the reality – he’s going under the knife.

It’s all about what grade the tumour is, which I won’t know until it is taken out and sent off for a biopsy. If it is low grade, then it is unlikely to spread. They need to get it out with a large margin. Oh god how am I going to manage the wait? My mum died of cancer 19 years ago and my half sister died of the same thing last summer.

As I leave Muggles with the vet and wander off alone, I'm hit by a tidal wave of emotion. It’s obviously not just about Muggles. All this unresolved grief is tied up with the death of Alex and the end of our relationship. Muggles was my last gift to Alex. The two of them were meant to grow old together. It wasn’t meant to be dealing with another potential tragedy. There is only so much I can take.

They call me five hours later to tell me he’s made it through the operation and I can collect him at 3pm. As I see him walking towards me looking woozy from all the drugs, I run to him and throw my arms around his neck – but I’m shocked. I thought it was keyhole surgery – clearly not. The scar on his back where they removed a pea-sized lump is the size of my forearm.

I want to ask him how he feels and if he understands what has just happened. What did he make of Beleza? I wish he could talk so he could tell me all these things, but instead, I can tell from his wagging tale, that all is well and he’s happy to be going home.