redness, soreness and heat around a wound suggest infection. as you are (ahem!) older, already being treated for long-standing health issues and feel crap, i would go to a walk-in centre if there is one near you tomorrow, or a+e if not. do not leave it til monday as time is crucial in getting infections under control. dog and cat wounds are notoriously dirty and need sorting at the time of incident if possible, particularly if you have paper-thin skin. you may also need stitches of some type (butterfly or sutures) to ensure the wound heals properly. if you really can't face any of that, call your out of hours gp tomorrow. but.....get it sorted sooner rather than later - you may end up regretting it if you don't. good luck (i'm a nurse, btw!) x