Hi, I’m Bandit. My friends and I want to tell you about a very serious subject: Mycoplasma.
As I’m sure you know, Mycoplasma is a serious problem for rats. Many, if not most, pet rats have been exposed to it and it is present in their respiratory systems. Fortunately, otherwise healthy rats are able to keep the bacteria under control and are asymptomatic for most of their lives.
But, unfortunately, when rats are stressed and their defense are weakened, they are less able to keep their Mycoplasma infection under control. That’s why many rats only develop symptomatic respiratory illness when they are older, although they had Mycoplasma almost their entire lives.
That’s right, Bandit. Mycoplasma is very difficult to treat, because they are so sneaky and good at “hiding” from our immune systems. Here is a very interesting article about “clever” Mycoplasma bacteria. They are even able to hide inside our own cells! Even when antibiotics slow their growth and even kill most of them, some are often “hiding and sleeping”, so the infection can come back again later when they “wake up.” That’s why, rats gets with a chronic Mycoplasma infection may need to be treated for the rest of their lives.
So, is there anything we do about those sneaky Mycoplasma hiding inside of our cells? Maybe! The other day, there was an announcement about a clinical trial. Apparently, Ambroxol, a common cough medicine was found to be possibly effective against Parkinson’s Disease!
Ambroxol helps against Parkinson’s by increasing the activity of Lysosomes, which are the cell’s garbage disposal machines. They then work harder cleaning toxins out of nerve cells. Toxins that would otherwise eventually kill those cells. This helps slow or prevent the progression of Parkinson’s Disease. There are probably other neurological diseases where neurons are essentially poisoned from within where Ambroxol might help. Alzheimer’s Disease, perhaps?
That’s very interesting, Spot. Amazing, even! But what is the a connection with Mycoplasma?
Well, Dot, because hard working Lysosomes might also do a better job chewing up nasty, sneaky Mycoplasma hiding inside lung cells. Lysosomes chewing up unwanted garbage in cells is called Autophagy, and scientists believe that is an effective weapon against Mycoplasma bacteria:
Autophagy-activating strategies to promote innate defense against mycobacteria
Ambroxol with antibiotics was shown to be a more effective treatment against Mycoplasma Pneumoniae in children than just antibiotics in several clinical trials.
Hey, Spot, you said that Ambroxol was a “cough medicine,” so I guess it must do more than just help our cells’ garbage disposals get rid of bacteria, right?
That’s right, Kitty!
Aside from Ambroxol’s potentiating of Autophagy, is also has other benefits for rats with Respiratory illness. Ambroxol has 50 years history as an expectorant cough medicine. It works by loosening up sticky mucus, so it is easier to cough it up and clear out the lungs. It also reduces respiratory inflammation and was proven to reduce asthma in rodents. It even acts as a mild, topical pain killer, to sooth our sore throats.
Ambroxol helps us breath easier and feel better!
And, by increasing the flow of thinner, less sticky mucus, it helps antibiotics work better. There is considerable evidence about Amboxol’s value treating respiratory illness in the very young and the very ill. It is even being researched as a treatment for the Coronavirus COVID-19 and Boehringer-Ingelheim has donated Ambroxol to China to help treat patients.
Friends, I’m just a rat. I don’t have a degree in medicine. But, if your rat has respiratory illness caused by Mycoplasma, please ask your vet to consider giving him or her Ambroxol in addition to antibiotics. If he or she agrees, your vet or pharmacy can help you obtain it.
Ambroxol and Azithromycin seem to be a good combination for young, pregnant and lactating rats with respiratory symptoms, and they have no problems with it in their drinking water (suggest 25mg Azithromycin and 2.5mg Ambroxol per 250ml water, sweeten if needed.) Analogous to the dosage for Human children, the dosage for rats was first given here as 0.5 to 1 mg/kg BID. Brian raised that figure later. His 2021 Roof Rat care course puts it at 10 mg/kg, so about 10 mg/kg per day is the figure this site uses now, best given by syringe. Recent rat studies back the higher number: they dosed rats by mouth at 10, 50 and 100 mg/kg per day, which makes 10 mg/kg per day the lowest dose tested.[1][2] Ambroxol is a mucolytic adjunct that helps antibiotics work, it does not kill Mycoplasma on its own.
You may add amoxicillin depending upon severity and if they don’t respond (it treats additional bacteria that Macrolides will not, but has no effect on viruses or Mycoplasma.)
Doxycycline and/or Enrofloxacin for older rats not responding to treatment (not recommended for young, pregnant or nursing rats.)
Please also see my FAQ: My rat is sneezing or coughing what can I do?
Our rats are always adopted out for free to good, vetted homes. We never sell them, and there are no deposits or fees. When a litter is ready, we place the babies with people we have gotten to know and vetted. If you would like to adopt one of our rats or come meet them, please contact us.
Editor’s note, updated 2026-08-17. The water recipe above, 2.5 mg per 250 ml, is Brian’s own, restored to what he wrote in February 2020 after we had shown a higher number of ours inside his sentence. Disagreeing with him is fine, putting our figures in his mouth is not. The 10 mg/kg per day is also his: he raised the dose himself in his 2021 Roof Rat care course, which is later than this post. Our own arithmetic for the water recipe is set out on our ambroxol page. The 2.5 mg water recipe and the 10 mg/kg per day figure do not deliver the same dose, so treat the water recipe as unsettled, and ask a vet.
References
- [1] Frota GM, Santos WGB, Tenorio-Meireles J, et al. “Analgesic and Anti-Inflammatory Activity of Ambroxol in the Treatment of Endometriosis: An Experimental Study in Wistar Rats.” Pharmaceuticals (Basel) 2026;19(4):641. PubMed.
- [2] Mesquita MJTAM, Cruz ACSND, Teixeira JTAMMM, et al. “Therapeutic Potential of Ambroxol in Osteoarthritis: A Drug Repurposing Study.” Pharmaceuticals (Basel) 2026;19(5):677. PubMed.
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