Thank you for the additional information.
I am sorry to hear that Sally swallowed a piece of dental floss. This is concerning as some cats can develop an intestinal obstruction called a linear foreign body from a piece of dental floss. At this point, since she ingested the dental floss only two hours ago it is most likely still in her stomach and has not passed out into her intestines yet. This is important as we still can induce vomiting to try to get the dental floss back out.
The safest way to induce vomiting in Sally would be to give her 3% hydrogen peroxide orally. The dose would be about 1 teaspoon for a 10 pound cat. You can use an oral syringe to give her the peroxide. As you can imagine this is not easy to do in cats as they are very resistant and agile when we try to give them anything orally. Therefore if you are unsuccessful or concerned you will not be able to give her the peroxide, I would then recommend taking her to an emergency vet for more help. If she does not vomit after the first dose within 15 minutes you can give her a second dose. Hydrogen peroxide is generally safe though this can moderately to severely irritate her stomach lining and esophagus in rare cases.
Other then inducing vomiting the other option would be to monitor her very closely over the next 48 hours. There is a chance that the dental floss will pass through her intestines without causing any harm. The symptoms of a linear foreign body obstruction are vomiting, diarrhea
, abdominal pain, lethargy, and lack of a normal appetite. If these signs are seen in the next 48-72 hours, then I would contact your vet right away.
If you do see the dental floss passing out of her rectum do not pull on it, yet cut the pieces off that she has passed out. Pulling on the floss could cut her large intestine causing significant pain for her.
Hope this helps to answer your question - if not or if you have any more questions please feel free to reply by clicking on the "reply to" button. Thank you for your question.