My male dog's penis is out, he's tired, and has worms. What's wrong?

Dogs can become sexually aroused even if they aren't sexually active, getting an erection. If his penis is swollen and sticking out, I would be concerned that the swelling could potentially constrict his urethra, leading to difficulty urinating. Because he's having trouble walking and his penis is swollen, I recommend you taking him into your vet to have the paraphimosis resolved. It's important to have him seen now, as it's causing him difficulty walking and you don't want it to lead to a constriction of the urethra.

If a male dog is aroused by a female dog that is in heat and close by, the penis will become erect. You typically don't see the penis, as it is "hidden" inside the prepuce, or sheath. Depending on the size of the dog it can be quite long, so I would consider this likely to be normal as long as it returns completely inside the sheath once the arousal is over.

Yes it is. He could be suffering from priapism, which is an abnormally long-lasting erection. A dog's penis is not meant to be exposed all the time and will dry out and become cracked and covered with debris, like carpet fuzz if this problem is not addressed by your veterinarian right away. If it continues to happen and he is not neutered, I suggest having him neutered as this will lessen the amount of male hormone in his system that can trigger this behavior and condition.

There is gland at the base of their penis that can get enlarged when excited and not fixed. If his penis was out and this gland was enlarged with blood he may have gotten too excited which caused the increased blood flow to the area. If this is the case the swelling and blood should completely be gone with his penis back in within 30 minutes. If it is not then I would take him to a vet for further treatment

Unneutered male dogs will masturbate and have discharge from the penis on occasion. This is normal as long as his penis does not stay exposed from it's sheath for longer than an hour or so. If it stays out too long it is an emergency and he needs to see a vet. If you do not like this behavior you can have him neutered which will probably help.

That could be due to a paraphimosis, which is basically when the foreskin becomes trapped behind the glans penis, and cannot be pulled back in normal position. Chronic paraphimosis should be treated as glans penis can get inflamed/traumatized. If not paraphimosis the sign you described could be completely normal and due to physiological constant excitement. I would recommend recommend a check up to rule out paraphimosis.

If Leo is that ill and had elevated WBC counts, it is possible that the penis infection is what is causing it, or there may be something more systemic going on. However it would be hard to give a definite answer to that without seeing the full blood work and examining him. If the area is infected, keeping it clean and continuing antibiotic treatment is best. If the penis is not fully retracting into the sheath, it could be an issue called paraphimosis causing it, which is caused by either swelling or other obstruction preventing it from retracting fully. Your vet may want to monitor the area and may recommend surgically opening the sheath some to allow the penis to retract if needed. If the medications don't seem to be helping, hospitalization with more intense therapy may be needed to help him feel better.