Ask a Dog Vet and Get Answers to Your Dog Veterinary Questions
Hi, this is Dr. Gabby.
That really sounds like flea saliva allergy because the fleas most commonly bite over the lower back.
If he is allergic to flea saliva one flea bite will cause him to have an allergic reaction. So even though you may not see a flea or flea dirt it could still be the problem.
Usually hairloss over the lower back is flea saliva allergy.
So as long as he is not on any other medications you can give him over the counter benadryl.
1 mg of benadryl per each pound of dog every 12 hours.
You can also apply over the counter hydrocortisone cream to the itchy areas. It is not toxic if ingested.
Then you need to do flea control.
You can try
Seresto flea collar
Flea busters to treat the carpet (www.fleabusters.com)
Does that help? Do you have any additional questions?