My overweight dog need helping!

I have an fine relationship with my parents, it’s easy to control emotions and sometimes it can be too much for me to handle. Getting into conflict with them is like hitting a brick wall and I’ve kinda have become quiet rather than tried voicing any opinion because it always ends in a shouting match and they never listen anyway. Therefore, I have stayed with my boyfriend and his family, because of the relationship with my parents.

But until i came home that I realised how much they have overfed the dog and gave it little to no exercise and little exercise and I tried to voice my opinion but my parents just insisted that it is ‘muscle’ not fat. They blame for her medication (she is taking an antiseptic for an underlying condition).

Yesterday, We took my dog into the vet for a checkup as she had an operation some months ago and when and when my mom was told her weight she was VERY surprised and unsure of how and she gained just that -althought I had told her multiple of times that our dog was overweight.

Before being locked up, she weighed 13kg, and for a small dog is still quite heavy, but now she is 16.3kg. It made me worry that she was overweight especially because we had a near-death experience with her when she was seriously ill and had surgery.

The dog gets fed wetfood twice a day (in total 2/3 of a whole can of dog food), once at 6am and once at 6pm, and they leave small bowl of biscuits is left out for her to graze on throughout the week. My parents also give her a dental chew for her teeth/bad breath and a cocktail sausage to have her steroid in.

I take her for two moderatly lengthy walks a day and she can go in the garden whenever she pleases- however because of university I can only walk her once on some days. Also due to the dog being pretty elderly it is difficult to exercise her very well because of her arthritis.

I suggested we put her in a caloric deficit but my parents didn’t listen and refused that we should, even though they also told me She’s ‘my dog’ in an attempt to guilt trip me into coming home during a national lockdown. (I’ll go into more detail on this but I feel like this might be off-topic or irrelevant.) And if I try to follow her path as ‘my)’ dog, then my parents would be very funny if they don’t control her treatment and I can’t always be by my side because college (despite going to work every day).

The dog seems happy but, like I said before, I am worried for her health. She’s been my best friend for just over 10 years and nearly my only friend at some points and it’s terrifying that something like this could bring her life to an end way closer than I hope.

If you have any solution that can help my dog, please do share to help her have a better health