Should I be concerned about my cat? He ran under the automatic soap dispenser and got dish soap all over his tail. I assumed he licked it all off himself, but now, in the morning, he's drooling, and not acting like he normally does.

If your cat has consumed dish soap and is drooling, it's likely that he's suffering from detergent poisoning.  

Symptoms of detergent poisoning include drooling, muscle weakness, vomiting, depression, seizures, lack of appetite, and diarrhoea to name but a few.

If you suspect that your cat has detergent poisoning it's important that you seek the advice of a vet to ensure that your cat can be treated appropriately. 

Treatment for detergent poisoning in cats

Treatment of detergent poisoning varies depending on the type of detergent the cat has ingested.  For regular soap, the vet will usually advise that either milk or water are administered.

In more serious cases, pain medication will often be administered, along with fluids.  If detergent has made its way into the cats eyes, a vet will commonly flush the eyes with a sterile saline.

Prognosis

Prognosis of detergent poisoning varies depending upon the type of detergent ingested.  Your cat will likely recover pretty easily if he's ingested regular soap and you seek treatment from a vet.