Is it safe to use flea spray on my dog with a flea bite rash?
If Dusk has a flea bite rash, I would be concerned that the Fronline spray isn't working. If it was working, she should not have flea bites. I personally have encountered resistance to Frontline, as have some of my colleagues; therefore, I would recommend trying another flea prevention. She should see a vet for the rash if it's inflamed, and I would take her into the vet in the morning. For now, I would not put the spray on Dusk if she has this rash, as it may work it worse. She may need treatment for the rash, such as an antihistamine or steroids, which can be prescribed by the vet tomorrow. You can give her Capstar now. It's a one time pill that starts killing fleas in 30 minutes, and it safe to give with other flea treatments. As for flea protection, given that she has a rash, I would avoid a spot on treatment, and give her a pill protection such as Comfortis or Nexgard. You will also have to disinfect the environment. Wash her bedding in hot soapy water, and vacuum the furniture and carpet surfaces. You can use a spray to kill fleas in the house, such as Indorex, or a flea bomb would work well to kill the fleas in the home. Please take Dusk into the vet tomorrow.
Updated on September 23rd, 2025