Rat Health


The Healthy Rat


Rats are very clean animals and can get sick very easily with poor husbandry, dirty cages, dusty rooms, extreme temperatures and artificial scents. Keeping your rats’ cage clean and free of dust is important in keeping them healthy.

But, no matter what, your rats are likely to become sick at some point in their lives so it’s important to know what to look out for. Your rats should be seen by a veterinarian regularly for check-ups. Rats are very good at hiding illness so once you begin to see symptoms of illness, they have already been sick for quite some time.

Teeny Snoots alum, Arrow and Teeter Totter illustrated by artist @luce.tooth

Signs of Illness

Common signs of illness include sneezing, lethargy, weight loss, dull eyes, disinterest in food, low interaction, puffy fur, squinty eyes, red staining around the nose and eyes, and unusual chirping or grumbling. These symptoms can be serious and you should contact a vet immediately.

Disease in rats can progress very quickly so do not delay seeking medical treatment. Spend lots of time with your rats so you know how they look and feel when they are healthy so you can quickly identify when they aren’t feeling well!

(American College of Laboratory Animal Medicine Series, 2015)

how do i know if my rat is sick?

What Is Porphyrin?

Porphyrin is a reddish secretion produced behind the rat’s eyes, and can appear around a rat’s nose and eyes. Porphyrin plays important roles in the rat’s health and can be an important indicator that your rat is in pain or sick. Small amounts of porphyrin are normal and healthy; however, a lot of porphyrin can indicate that your rat is sick, in pain or otherwise unhappy. If you’re noticing frequent red staining around your rat’s eyes and snoot, pay close attention to how they are feeling and schedule some time to see your vet!

When rats are stressed, there can be an excessive secretion of a reddish substance call porphyrin from rats’ eyes and noses. Rats do have some porphyrin produced while they sleep and will groom it off after they wake up. A sick rat will have porphyrin consistently present. Rats can progress very quickly so do not delay seeking medical treatment.

The rat in the above photo has porphyrin around her eye. This can indicate illness or pain, allergies, or it could be because she has just woken up and hasn’t groomed yet. If you notice porphyrin around your rat’s eyes and nose, monitor them to see what the cause may be. Ask yourself:

  • Does the porphyrin go away throughout the day?
  • Is it constantly on their eyes or nose, regardless of time of day?
  • Does your rat produce larger amounts of porphyrin while they sleep?
  • Is your rat showing any other signs of pain or discomfort, such a puffy fur, squinty eyes, etc.?
  • Are there any allergens in the room that could be bothering their eyes and/or nose?
  • What kind of bedding do you use? Could the dust be in her eyes and/or nose and bothering her?
  • Is the fan/air conditioner/vent/heater pointed directly at the cage or too close to the cage?
  • Does your room need a humidifier or dehumidifier?
  • Have any candles, incense, cigarettes or marijuana been smoked in the house?
  • Have you used essential oils and other toxicants too close to their enclosure?

If you notice the porphyrin remains consistently on your rat, there is likely an underlying issue that your veterinarian should assess.


Common Illnesses & their symptoms

The chart below describes common illnesses in rats and their associated symptoms. This chart is not a replacement for veterinary care – it is to assist rat families in understanding their rats behaviour. If you feel anything is off with your rat, always seek veterinary attention. Rats hide illness very well and by the time they show symptoms, they have have been sick for a while. Rat health can decline very rapidly without medical attention in some of these cases.


common medications your vet may use

The chart below shows some of the medications your vet may prescribe your rat. If you feel you would like to try a medication that your vet hasn’t yet tried, mention it to them and request a prescription. The Rat Guide is a great resource for education on rat health, medications and therapy, and is based on primary literature from trained professionals. Rat medicine is fairly new, despite the use of rats in laboratories, so be sure to do your own reading about your rat’s illness to help support your vet. New research often describes the use of using various new medications on specific illness, and your veterinarian should be interested to hear about the studies you’ve read that relate to your rat’s therapy.

If your rat is prescribed medication, be sure to use it exactly as directed by your veterinarian and finish the full course of antibiotics even if your rat is feeling better.


How do I know if my rat is in pain?

The Rat Grimace Scale

The Rat Grimace Scale was developed by Sotocinal et al. 2011. It is a visual scale that tells us if a rat is feeling pain or discomfort. In the graphic below, the rats on the left are happy and feel good while the rats on the right are in pain and discomfort. Use this scale to help understand how your rat feels!

Squinty eyes (orbital tightening) – In a happy, pain-free rat (left), the eyes are wide and bright. In a painful rat (right), the eyes are squinty and tight.

Cheeks less bulgy (nose/cheek flattening) – In a happy, pain-free rat, the nose and cheeks are puffy and short. In a painful rat, the nose and cheeks look flatter and longer.

Ears pointed sideways – In a happy, pain-free rat, the ears are pointing forward and curious. In a painful rat, the ears are turned backwards and may appear lower on the head (may not seem on top of the head like usual).

Whiskers pointing forward – In a happy, pain-free rat, the whiskers are spread out loosely to the side of the face or may appear pointing backwards. In a painful rat, the whiskers are pointing forward and look stiff.

Puffy/extra fluffy fur – In a happy, pain-free rat, the fur is flat and relaxed against their bodies. In a painful rat, the fur is erect and the rat appears “fluffy”. This may be harder to see in rats with non-flat fur coats.

If you feel your rat is sick, in pain or uncomfortable, please take them to a rat-savvy veterinarian ASAP. Rat health can decline very rapidly after symptoms begin showing so quick action is required.


Download Our “Healthy rat” pamphlet below