Thank you for your patience. These symptoms Lucy has had for the last couple of days is definitely a bit of a concern. As you can probably imagine, there are quite a number of potential causes for this funny noise Lucy has been making ranging from hairballs, to a foreign body in the throat (a grass blade or similar), to feline asthma (yes! cats can get asthma too), to a lower respiratory tract infection, or even a primary heart issue. If this has been relatively regularly on/off over the last couple of days, then I would definitely recommend a follow up visit with your Vet to get a better idea of what might be causing this.
As she has been sick for the last couple of days along with this strange voice change - your Vet may want to sedate Lucy to double check she doesn't have a grass blade foreign body at the back of her throat causing irritation to the nasal cavity as well as causing this cough. This is simple to treat - your Vet would just remove the grass (carefully) and put your girl on antibiotics. If he or she did check under an anesthetic and nothing was there, then the next step would be to take a chest and throat xray as well as take a fluid sample from the lungs - a procedure called a BAL. These further procedures can help give us information about whether she may have a lung infection, asthma or a heart problem to name a few.
I really do think it is best to follow this up tomorrow if your local vet is open on a Sunday. If you can get her to your Vet tomorrow, that would be the best plan. If she is eating and drinking ok - and able to keep it down, then Monday morning would be ok. In the meantime - worming her would be a good idea. Use an allwormer like drontal or milbemax for this. You could also think about using a flea product that covers heartworm if you were concerned about this.
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