Urinary blockage??

2 1/2 weeks ago my outdoor cat was very lethargic I took him to the vet and they found he had a urinary blockage they put a catheter in him which stayed for 24 hours and put him on the hills urinary care diet. After taking him home he started using the bathroom multiple times a day but now I noticed he hasn’t used his litter box in the past 3 days I am very worried. is it possible he has another urinary blockage so soon even tho he has been drinking tons of liquids and is on the special wet and dry food. It is possible he may be using the bathroom outside but he’s only ever out from 1-4 am I feel like he should be having to use his box through the day. So my question is how soon can cats get urinary blockages after just having one?

Hello!  It is now thought that urinary "blockages" are often caused by spasms in the muscle that lines the wee tube, which effectively close it off.  They can occur at any time and they may, in cats, be particularly associated with stress.   Being predatory carnivores rather than pack animals, cats do not communicate 'I'm stressed' behaviours as easily as other animals (dogs have an evolutionary advantage in letting their pack know when they are worried;  cats do not).  The first that many owners know of their cats being stressed is when signs of cystitis begin.

For this reason, it's important to keep tabs on your cats' urinary habits as closely as you can.  For indoor-based  cats this is easy:  owners can keep notes e.g. in a diary, to remind them what 'normal' is.  It can be useful to provide a choice of trays, some of which are not overlooked, and monitor them.  Keep your eyes open for strange urinating behaviours;  for unproductive straining or repeated visits to known urinary sites - or new ones.  For outside cats however, we hear that such advice can be difficult to manifest practically.  Urinary disease may present as lots of uncharacteristic 'in and out' behaviour.  Useful measures may include encouraging your cat to drink, adding water to food, providing extra litter trays with different kids of litter, even if you cat doesn't usually use an indoor tray (and perhaps some covered ones outside if that's an option).   New cats in the area may provide a clue to be extra-vigilant.  You might also pick up some advice from reading about urinary problems / FLUTD / blocked bladders in our blog and from visiting icatcare, another website run by experts in the subject.   The truth is that there is no easy answer.   Keeping an outdoor cat inside to monitor them can also be damaging, because urinary problems are thought to be caused by being stressed and staying inside can be stressful for many outdoor cats.  It may be a case that you can only do your best and hopefully some of the resources I've sent you to, together with your gut instincts, will help you to prime your gut instincts.

(last line)  It may be a case that you can only do your best and hopefully some of the resources I've sent you to will help you to prime your gut instincts.

Wishing you and you boy the best of luck.  Sometimes a cat does not have another blockage for years;  sometimes they have another one only a few days later.  Keeping them relaxed with access to toileting sites is thought to be key.

Your vet will be a good person to help you make some of these decisions  eg the question of whether or not your cat should be allowed out.  iCatcare website and our blog have lots of helpful articles about blocked cats and FLUTD