The abscess needs to drained, and I would, at this point, have the abscess cultured to see Exactly what bacteria is causing the infection, instead of throwing more random, broad spectrum antibiotics at it.
I t Would probably be a good idea to find another vet, and have the medical records sent over, you don't need to speak to your old/first vet, the new vets office will request the records.
But I would be Sure that new vet is open to culturing the abscess or the process starts all over again.
It's a fine line, and a delicate balance, between telling your vet what to do and asking to be a part of the decisions made on your cats behalf.
Also, your cat NEEDS probiotics right away because of all antibiotics.
Antibiotic Resistance and
Why You Should Be Concerned About Antibiotics and Your Pet
Antibiotic resistance is not only a serious concern for humans, it is also a rapidly growing problem for our companion animals.
Veterinarians are seeing dramatic increases in bacteria strains that are resistant to multiple classes of drugs.
As the problem of antibiotic resistance in pets continues to grow, vets will have fewer and fewer options for treating infections in your dog or cat.
How to Help Your Pet Stay Safe
If you suspect your pet has an infection -- or if a veterinarian makes a diagnosis of infection -- before you agree to a course of treatment, if the doctor doesn't suggest it, I recommend you ask him to do a culture and sensitivity test.
When a doctor prescribes an antibiotic without a culture and sensitivity test, he or she is making a guess at what type of infection is present and the best drug to treat it.
And while many physicians and veterinarians are very good guessers, given the growing danger of antibiotic resistant strains of disease-causing bacteria, in my opinion, there's no longer any room for error. Each time an inappropriate or unnecessary antibiotic is prescribed, the potential for resistance increases.
A culture and sensitivity test gives your pet's veterinarian two very important pieces of information:
The precise organism causing the infection
The best drug to use to kill it
This information is about half way down the entire article ... there are many more articles on the subject of antibiotics and pets + probiotics at this, and other websites.