What Would A Respiratory Illness In My Kitten Look Like??

my kitten is 4 months old (and a little chubby, but still cute) and she’s been coughing for about 3 weeks now. the first 2 weeks i thought it was just normal cold symptoms that come with winter in south florida…but when she started to sleep alot and stopped eating and drinking well (she’d only drink water from the tap), I took her to my vet. They checked her out, put her on antibiotics and gave me some medicine for an upper respiratory infection….which ran its course in 1 day & seemed to be gone by 2 days

but then this past week she hasn’t been eating or drinking much at all- not even water! every once in a while she’ll eat something small like grass or kibble, but nothing substantial enough that would show up on x-rays yet….i do know it seems like there’s no problem with swallowing because there are times where I think ‘hmm maybe he ate something’ so I take him back to the vet…..no stomach parasites found either

so what else could cause such an illness? his lungs sound clear based on his chest x-rays so far….however he does have runny eyes & nose lately which were never present before this sudden onset of illness