The tabby cat was found inside the box – which was taped up – at around 1pm on Tuesday 26 July in a field off Goat Mill Road. Food and drink were found inside the box.
The kindhearted member of the public then took the cat to RSPCA Merthyr Tydfil veterinary clinic.
RSPCA inspector Sophie Daniels, who is investigating the incident, said: “The caller came across this cat after their dog barked and found the box – and we are really thankful to them for bringing this cat to us.
“After an examination it was found he has viral mouth issues and is now on medication, but thankfully he doesn’t have any injuries.”
This abandonment comes as the RSPCA recently launched a fundraising campaign called Cancel Out Cruelty which calls on the public to support the charity so frontline staff can save more animals in distress this summer.
RSPCA Cymru is now appealing for anyone with information about this abandonment to call the inspectorate appeal line on 0300 123 8018.
Sophie added: “If anyone can help with our enquiries please get in touch. We never know the exact reasons why owners abandon their animals – no doubt there could be a number of factors, from people’s circumstances changing to the rising cost of living.
“But every animal has specific welfare needs and it’s so dangerous to leave any animal abandoned and having to fend for itself. Even though we bid to Cancel Out Cruelty this summer, sadly we fear we will receive many many more reports of pets being abandoned.”
For those who find themselves struggling, there are many reputable animal welfare charities who can offer help and advice and we encourage anybody in a difficult situation to seek support. Information is also available on the RSPCA’s website.
The cat has now been transferred to RSPCA Llys Nini Branch’s animal centre in Penllergaer for further care and treatment.