Yes it is quite possible.
The infection could become more serious. For instance, Athletes Foot is an infection, usually, between the toes. If left too long, cracking and flacking skin can become irritating and painful.
Any cut or puncture wound could become infected if left untreated.
There could a number of factors. The cow could've become cystic, become infertile from some sort of infection (especially uterine infection) or from age. She could also be very thin or very fat, disabling her ability to settle successfully.
A fungal infection could cause those symptoms.
ANY infection needs to be treated immediately with antibiotics, as you could become VERY sick if the infection enters your bloodstream. If you get "blood poisoning" and it goes untreated you could possibly die.
Bacteria become resitant to antibiotics by evolution .
There are several types of microbes that could cause infection and they may be acute chronic or latent infections. A microbe that could cause an acute infection is rhinovirus, one that could cause a chronic infection is hepatitis C and one that could cause a latent infection is herpes zoster.
This is almost impossible to answer without a more specific question. A woman could become pregnant. Could develope STDs, could have pain, could get a bladder infection and so on. A man could face the same.
Sounds like he has a urinary infection of one type or another. Take it to the vet. It could become serious.
Cellulitis of the eye is a condition where the tissues and skin around the eye become inflamed. They could also get infection and this is what causes the inflammation.
If you mean leak urine, then nervousness, being excited, or poor bladder control could be the issue, or possible a urinary tract infection. If the dog is not spayed, the she could be in heat, which is a time or ovulation in which a dog could become pregnant, and she should be kept away from male dogs.
It could be your period or an infection if you are female. If you are a guy, it could an injury or infection to your urethra.