The skin turned blue from a dog bite, but there's no open wound. Do I need a preventive injection?

Generally speaking, whether a rabies vaccine is needed after a dog bite that causes bruising but no visible wound mainly depends on whether the skin is broken. The analysis is as follows:

1. Yes, vaccination is required

Bruising after a dog bite usually indicates internal bleeding under the skin. In such cases, it's important to check for any skin breakage. However, visual inspection alone is insufficient. One can wipe the bruised area with iodine tincture; if pain is felt, this suggests the skin is broken. For safety, the rabies vaccine should be administered as soon as possible within 24 hours and according to schedule. Before vaccination, thoroughly wash the affected area with soap and water for at least 30 minutes, and disinfect the site with iodine tincture.

2. No, vaccination is not required

Rabies is typically transmitted when bacteria from a dog's saliva enter the body through broken skin. If there is only bruising and careful examination confirms no skin breakage, then the rabies vaccine is not necessary.

In summary, after a dog bite causing bruising but no open wound, one must visit a正规 medical facility for proper evaluation. The decision on whether to receive the rabies vaccine should be made based on professional medical advice, ensuring optimal prevention of disease.