So the arguments start re indoors vs outdoors! I personally prefer cats to have outdoor access and think the benefits to their mental health / stimulation and physical health far out weighs the risks of letting them out in most cases. I do however accept there are some circumstances when free outdoor access is not always appropriate. What I think people sometimes fail to realise is that whilst cats do sleep a lot when awake they are also extremely active with high prey drive and being crepuscular often keep hours that are not entirely in line with our own, all of these things need to be facilitated, they need to be provided with adequate ways in which to be able to express normal behaviours which whilst achievable indoors when done to a good standard can be quite expensive and invasive and there is no denying that many house cats are obese putting them at higher risk of many health problems. Therefore keeping them in itself is not nessisarily a bad thing but keeping them in one small room with no facilities to run, jump, climb. No toys to chase and hunt or provide mental stimulation is far from ideal.
Cats on a wet only diet usually have an average recommendation of 4 pouches a day per cat based on a cat whose Ideal weight is around the 4kg mark (average cat size). 1 pouch each plus biscuits is fine but if he's running out of biscuits and not compensating with additional wet food during this time this is not adequate or acceptable as the cats will be going hungry at the end of every month.
With regards to litter trays the guidance is one per cat plus one extra, this is particularly relevant to indoor only cats, therefore 1 litter tray for two cats is not adequate there should be 3. Cats toilet several times per day and cat pee is very strong, having a single litter tray for 2 indoor cats and only cleaning it out every 4 days is not going to be anywhere near adequate. It needs poo picking probably twice per day and fully emptying and cleaning every other day. Whilst being unspayed will undoubtedly add to the urinating / marking behaviour it is also likely behavioural if their facilities are not clean enough or they are stressed. Getting the smell of cat urine out of furnishings is a nightmare and if they can smell where they have been they are likely to go there again.
With regards to being unspayed not only can coming into heat every few weeks be stressful for them but it increases their chance of marking, escaping and developing mammory tumours and pyometra (a life threatening uterine infection), if these occur it’ll cost a lot more to get sorted than the initial outlay for a spay would have. If he is in receipt of any benefits many charities like the PDSA or Cats Protection offer heavily discounted neutering and microchipping. The outlay now could save a small fortune in the future.
With regards preventative medications I think its unwise to have no vaccines at all so I would always recommend a full kitten course as virus’s can still be brought in but I also believe in many (not all) cases vaccines often last longer than than they are guaranteed for (I titre tested my dog) and many of the diseases that are vaccinated against in cats are transmitted by direct contact (fighting / mating) so as an indoor cats risk is pretty low. The biggest parasite risk to indoor cats is fleas as they can and do hitch a ride on people and if I had a pound for every person with an indoor cat that had gotten fleas and saying ‘but they don’t go outside’ I’d be rich so flea treating is definitely recommended on a regular basis, again this is something where treating the problem once its there is so much more expensive and time consuming than the treatment to prevent it in the first place. You can get a 4 month supply of Advantage online for around £12 with postage. Worms are also a minimal risk in a housecat, the biggest risk is tapeworm which comes from fleas, prevent the fleas and the worms are unlikely, in an indoor cat treated preventatively for fleas I’d probably only worm the cats 6 monthly. Drontal bought from an online pet pharmacy is about £2 per tablet. This isn’t significant cost.
Under the Animal Welfare Act, The 5 Welfare Needs which are a legal requirement for any animal are:
The need for a suitable diet - this includes a suitable amount of food (to prevent both obesity and malnourishment) and access to fresh water and is something your friend is not meeting if they are at times going without enough food.
The need to be able to exhibit normal behaviour patterns - if the cats have no access to adequate exercise, facilities to run, jump, climb, chase, hunt, scratch your friend is not meeting this need.
The need for a suitable environment - they must have enough space appropriate to the species, comfortable resting areas and hiding places etc. Again limited to a small room messy room with no beds or adequate toileting facilities and that smells this is not being met.
The need to be protected from pain, suffering, injury and disease - this means prompt treatment should the animal because unwell or injured to prevent suffering.
The need to be housed with or apart from others.
From what you have said your friend is failing in at least 3 out of 5 of his legal obligations.
I’m not sure how you go about approaching this with your friend, its a tough conversation to have but hopefully those points will help. Also I have attached the DEFRA guide to cat care / welfare, maybe you could print it off and give it to him.
assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/697941/pb13332-cop-cats-091204.pdf