The Rat Fan Club

Below are autopsy pictures of rat lungs.

Updated 3/3/10.

Because most rats die with some disease of the lungs, it is difficult to get a picture of normal healthy rat lungs. These lungs aren’t too bad, but they are puffier and a darker pink than they should be. They should be about the color of the thymus gland and about ¾ this size. But this picture will get you oriented as to the location of the organs.

Here the left lung (on the right side of the picture) is normal in appearance. The right lung (on the left side in the picture) has some emphysema making it too puffy.

This picture is from a 4-week-old rat euthanized because of megacolon. The lungs are pretty normal looking, just slightly darker than they should be. The heart is quite large in proportion, probably because of the rat’s young age.

These pictures show some typical diseased rat lungs, a front and back view of lungs removed from the chest cavity. In the left photo, the lobe on the upper right that is lighter in color shows emphysema (lungs that can’t deflate puffed up with air) and the lobe on the lower right shows the cobblestone appearance which can be caused by Mycoplasma pulmonis. Notice how different they look compared to the lungs in the first 3 photos.

This picture also shows a combination of emphysema and the cobblestone appearance. See how big these lungs are.

This is a front and back view of lungs showing all 3 typical signs: emphysema, abscesses, and cobbblestoning. These lungs were from a 22-month-old rat (Agatha) who had respiratory symptoms for one month. She was treated with doxycycline, furosemide, aminophylline and prednisone and was finally euthanized.

This picture shows lungs that are completely filled with small abscesses. This is a common occurrence in rats whose respiratory symptoms are never treated with doxycycline or Baytril. It’s hard to believe that this rat was still alive until shortly before this! They don’t even look like lungs.

This lung, left of the heart in this picture, is puffed up and blotched with red. A biopsy was sent in for pathology, and the diagnosis was severe bacterial pneumonia. The white tissue to the right of the heart in the picture is enlarged lymph nodes. This 11-month-old rat, Stewie, had sudden labored breathing that was treated with amoxicillin and dexamethasone, but he died that night.

The 2 ½-year-old Himalayan rat (Lelan) who had these lungs died suddenly without symptoms. The pathology result was hemorrhagic infarcts. Possible causes included a coagulation problem, thromboemboli, or low blood flow due to heart insufficiency. The heart did have severe hypertrophic cardiomyopathy.

The white mass filling most of the chest here is a lymphoma tumor. You can barely see a corner of the very red lung to the left of the heart. This 35-month-old rat (Beans) experienced a gasping attack on 4/8/08 that responded well to treatment with aminophylline. Dexamethasone was also given. A chest x-ray on 4/15/08 showed fluid in the lungs and an enlarged heart, which was treated with furosemide and digoxin. He had already been on enalapril and atenolol for a month for reduced activity with good result. A gasping attack on 4/20/08 responded to aminophylline, and another dose of dex was also given. A gasping attack on 4/22 did not respond to aminophylline so Beans was put into oxygen, which did not help, so he was euthanized. Note that the tumor did not show up on the x-ray.

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