My dog's back legs are weak and his penis bled, but he shows no pain.

Oh dear! I'm afraid this is an extremely serious problem - Dachshunds are very prone to herniated discs in their spine which can cause rear leg paralysis, so I would be very concerned that this could be the problem. He could also have been injured somehow, or could have a neurologic disease of some kind causing him to not be able to use his legs. Bleeding from the rectum coukd be due to internal injuries or a serious illness of some kind. This sounds like a serious, life-threatening problem, so I would recommend taking your dog to an emergency vet immediately. He/she can do x-rays, blood work, or other testing if needed to help diagnose the problem and see what can be done to treat it.

Bleeding from the penis indicates a serious problem. In an unneutered dog, it could be a prostate infection, enlargement, or tumor. Some other possibilities include a urinary tract infection, bladder stones, or a systemic bleeding problem (coagulopathy). I suspect that his paw biting is unrelated and may be due to allergies or a hot spot, but he should definitely be seen by a veterinarian to determine the cause of both issues and come up with a good treatment plan. Best of luck!

It is more likely to be a bruise - fractures are very rare and extremely painful. Monitor for continued bleeding or any difficulty urinating which would indicate the need for immediate veterinary attention. Encourage him to drink fluids in order to keep the system flushed out and reduce the risk of any blood clots become lodged

This can wait until Monday morning unless the dog looks in severe discomfort from this. if this is not a young dog then a Prostate disease is very likely (cancer or infection), this definitely needs to be treated ASAP but it is not always an emergency.

Bleeding from the penis can have various causes: Xander could be suffering from a UTI, an inflammation of the prostate, penis or prepuce or a tumor. Since he is not eating and lethargic it is likely something that causes him pain and he may have a fever. You can carefully push back his prepuce (foreskin) and then inspect his penis for injuries or growths, or to see where exactly he was bleeding from or is still bleeding from. If he is still bleeding you should take him to an emergency room this evening. If it stopped bleeding but he stays lethargic or will not eat his breakfast tomorrow morning or if you find injuries on the penis , then you should call your vet for an appointment.

It sounds like your dog is likely in extreme pain, and he needs veterinary attention immediately. He may have fractures, internal injuries and bleeding, and may even have neurological issues from being hit by the car. If you mean that he is unable to urinate, that is a medical emergency, and requires immediate veterinary care. Your vet will assess him and recommend appropriate treatment, which will likely include pain medication, imaging and possibly surgical repair. Do not give pain medication to him without checking with your vet, as pain medications for humans can be toxic to dogs. Good luck, and I hope he feels better soon!

I see that your dog is not neutered - I'm not sure how old he is, but in middle-aged or older unneutered males it is common to see blood dripping from the penis as a symptom of an [enlarged prostate](https://www.petcoach.co/dog/condition/prostate-enlargement/). That is normally the first thing that I would check out in a dog with this problem. Other possible causes include an injury or tumor on the penis or the penile sheath, a bladder or prostate infection, bladder stones, kidney disease, or even a systemic bleeding disorder. I would recommend taking him to a vet for an exam - they will probably want to collect a urine sample for testing, check his prostate during a rectal exam, and examine his penis closely outside the sheath to look for any problems. From there, x-rays and ultrasound can be used to look at the prostate, if needed. If the problem is due to prostatic enlargement, this can normally be improved with [neutering](https://www.petcoach.co/article/benefits-of-neutering-castrating-male-dogs-puppies/) and does not typically cause any long-term problems.