Hello - I am Dr. Matt - I would be glad to help you with your question.
Does Holly lick or itch anywhere else on her body?
Has she had problems with her anal area before?
How long has she been rubbing her rear end on the floor?
Thank you for the additional information.
Are you seeing any swelling around her anal area?
An ointment such as 1% hydrocortisone ointment could be helpful. The two main causes of redness on the anal area would be an anal sac (small glands on the inside of the anus in dogs) impaction/infection versus an allergy disorder. The best way to determine the exact cause would be to have your vet check the anal glands. Sometimes these glands can be full of a thick fluid that needs to expressed. If the glands are empty then Holly most likely has an allergy to either ingredients in her food or pollens in the environment.
If you would like to try the hydrocortisone cream first that would be fine - you can apply this ointment every 12 hours to her rear end. You can also try an antihistamine such as diphenhydramine (Benadryl) at a dose of 1 mg per pound of weight ( 2 mg per kilogram) every 12 hours.
Hope this helps - please reply if you have any questions. Thank you!
If the home care treatments do not help in 48 hours though or she seems to be getting worse I would then take her to your vet to have the glands checked.
You are very welcome!