I switched you to the cats category.
How old is she?
What is her food?
I am so sorry your girl is not feeling well. This is most likely caused by an abscessed tooth or oral sores.
She must see a vet ASAP for an antibiotic or she will very soon stop eating due to pain.
The drawn face may indicate dehydration which is also very dangerous. See if she will drink tuna water or milk. Feed only canned food with water added.
She may also have had a stroke or upper respiratory infection. In any event she needs to be seen today.
She should also be checked for:
http://www.sniksnak.com/cathealth/uroliths.html http://www.sniksnak.com/cathealth/fusfaqs.html http://www.sniksnak.com/cathealth/urethral.html http://www.sniksnak.com/cathealth/hyperthyroidism.html http://www.sniksnak.com/cathealth/diabetes.html http://www.sniksnak.com/cathealth/renal.html
Please let me know how she is doing. I hope all will be well.
Sincerest best wishes,