Mum Missing, Dad Depressed 2 6wk Kits

[Worrid1]

I took on a friends 2 cats as she had an accident.
Male and Female born days apart from 2litters, neither was done and before i could get her done the inevitable happened.
Mum was an attentive mum and dad was as friendly as he is to everything.
Yesterday mum went out and isn't back, worryingly the male cat is seeming very depressed, calling her all night to no avail and he ignored tuna cheese and ham.
His reaction makes me think mum has come to harm he is now moping and no longer playful.
If his reaction is correct what do I do?
They are eating food but one is calling for mum.
They are both booked in for 'doing' on wednesday

 

[golondrina]

How old are the kittens and how many? Are they weaned. Are they kept warm? Is dad sleeping with them? If mom left only yesterday she may still find her way back. What measures have you taken to find her?

 

[Worrid1]

2 they're 6 weeks and eating although they were still nursing (mum has been discouraging them in last couple of days) Dad has been with them but he's not himself and is currently in garden calling for mum again.
They snuggle in their blankie together.
I've been to her usual haunts calling for her and had no response, she is a very chatty cat and if she'd heard me she would have cooed/chattered or meowed.

 

[Worrid1]

She knows today is shopping day and she is always waiting when I get back as she learnt very quickly she'd get treats as i unpacked (bit of ham etc)

 

[Abigailfosters]

Ideally she shouldn't be allowed to leave the house until babies are weaned and she is spayed. It's likely she has gone off to find another mate so when she returns it'd be worth getting her spayed straight away .
In the UK we have lost and found cat Facebook groups for most areas, have you tried posting a picture up online to see if anyone has found her? Fingers crossed all is well.

 

[war&wisdom]

Make sure to weigh the kittens to make sure that they're getting enough to eat, especially now that mom is gone.

Do you have KMR or goat's milk? It's a good idea to mix it into their wet food.