Rat bite fever is a serious infectious disease in people caused by the bacteria Streptobacillus moniliformis. People become infected either by coming into contact with a rodent carrying the bacteria or through consumption of water or food that has been contaminated with rodent droppings or urine. While any person who comes into contact with the bacteria is at risk of developing the disease, children under 5 years of age, adults over 65 years of age, and immunocompromised people are at higher risk.

A rat that sneezes a lot, has more tears than normal or has crusty eyes, or has a audible wheeze or crackle, is showing signs of a respiratory infection.

Respiratory infections in rats are often caused by viruses.  Many times the viruses are harbored in older rats that aren’t showing any outward signs of infection yet they are still capable of infecting younger rats.  This is one reason why it is important to avoid mixing rats of different ages and different origins together.

Rats are prone to a variety of lumps and bumps beneath their skin.  Many times these lumps and bumps are due abscesses, infections that accumulate pus beneath the skin.  Sometimes the masses are enlarged lymph nodes.  In older rats, typically 18 months or older, tumors are more common as the cause of lumps and bumps.  The tumors may be benign ones such as adenomas or lipomas, or they may be more serious ones classified as adenocarcinomas.  Most tumors are readily removed at a small size and many of them do not return if the surgery was able to completely remove the growth.  If you see a bum

If you decide to get a female rat as a pet in the future, it is very important to have it spayed when it is around 3 to 4 months of age. This eliminates the chance of ovarian disease and greatly reduces the chance of other reproductive diseases.  This also greatly reduces the chance of a rat developing a mammary tumor develop as she ages. It is one of the most important things you can do to extend her life.

Below are some pictures from spay surgeries on rats, some of which were performed due to a medical problem.

Rodents such as rats, hamsters, gerbils, and mice are chewers and gnawers. In the wild, these rodents feed on hard-shelled nuts, tough grasses, leaves, and bark that wear down their front teeth (incisors) and cheek teeth (premolars and molars). As a result, rodents have teeth that grown continuously to replace the portion that wears away with chewing.

Pets may be sent home with liquid medications.  An oral liquid medication must be given by mouth to be effective.  An injectable liquid medication must be given by injection beneath the skin to be useful.  Some injectable medications require that the medication is inserted into the muscle to be most effective.  It is important that you understand how to read the syringes that are sent home so your pet gets the proper amount of medication at each dose.

All exotic pets, even ones that appear to be outwardly healthy, have the potential to carry and spread contagious diseases that can impact the health of people.  This sort of disease is called a "zoonosis", "zoonotic disease", or "zoonotic infection".