In October 2013, Naegleria fowleri (a.k.a. "the brain-eating amoeba"), was confirmed to be found in the Louisiana public drinking water systems. I live in the southern US and am concerned, as I have dogs in areas where there are low waterways, and I provide them tap water to drink.

I found "Could your dog be at risk for brain-eating amoeba?" on PetMD, but the authoring doctor notes that while Deadly Microbes claims dogs are not at risk (just mice and humans), his research on the Veterinary Information Network revealed one potential case of an infected dog from 1997, (Steele, K.E. et.al. Amoebiasis in a dog with gastric ulcers and adenocarcinoma. J. of Vet. Diagnostic Investigation 9(1): 91-93. 1997.) (case). He was unable to confirm his findings as the the source document was unable to be located at the time of the article. The article has been located and the doctor has been alerted to its existence via Twitter.

I would assume the precautions I can take are to use distilled water to feed my dogs and prevent them from swimming or drinking from waterways or standing water.

So, the question remains: can dogs be infected by this horrible amoeba? Can I feel safe letting my dogs swim in the pond?

  • 1
    It may be unanswerable, but it's a great question! This is one everyone should share using the social networking share links below the tags.
    – jmort253
    Commented Oct 30, 2013 at 1:14
  • 1
    I suspect the amoeba is non-discriminating as the Deadly Microbes site states it affects both humans and mice. I am not sure I should be so bold as to revise this question to "Which pets can the brain-eating amoeba affect" because I don't think a "mice" answer will suffice, and I don't want this closed as too broad or as a list question.
    – JoshDM
    Commented Oct 30, 2013 at 5:41
  • 2
    I seemingly found a fulltext source for that cited source. vdi.sagepub.com/content/9/1/91.full.pdf immortalised by imgur here imgur.com/l2kQEth Commented Oct 30, 2013 at 8:08
  • 4
    I think the date was wrong. It was 1997, not 1977, which subtlety would make the article difficult to find. Commented Oct 30, 2013 at 8:09
  • 2
    @TomO'Connor ! A+ for effort! The reference the doctor listed had 1977. I've had a tweet sent to the PetMD article author, Dr. Patrick Mahaney alerting him to the source you provided and this question on SE.
    – JoshDM
    Commented Oct 30, 2013 at 16:42

2 Answers 2


I suspect the answer is theoretically "yes" because basic chemical makeup and temperature of a human brain is not dissimilar from a canine brain.

So the question is, can the canine brain become infected with the amoeba? In humans, the infections have come from swimming in contaminated water and taking the amoeba in through the nose or through use of a Neti-Pot.

The term "brain-eating amoeba" makes the amoeba sound like a tiny zombie stalking your skull. But brains are accidental food for them.

According to the CDC, N. fowleri normally eats bacteria.

The good news is that if you were to drink a glass of water infested with N. fowleri amoeba, you would not get a brain infection. It infects people by getting into your nose. Source

So the risk comes from ways your dog can get water in the nose. And then, even if the water gets into the nose, only a small percentage of time will that water contain an amoeba, and even if it does contain the amoeba, there is a good chance the amoeba will not make it to your dogs brain, but instead end up cycling through his system the way the rest of the water does.

How Do Amoebas Get in the Brain?

Studies suggest that N. fowleri amoebas are attracted to the chemicals that nerve cells use to communicate with one another. Once in the nose, the amoebas travel through the olfactory nerve (the nerve connected with sense of smell) into the frontal lobe of the brain.

How Frequently Do People Get Infected by Brain-Eating Amoeba?

Even though N. fowleri amoebas are relatively common, they only rarely cause brain disease. N. fowleri disease is known as primary amoebic meningoencephalitis (PAM). It occurs from zero to eight times a year, almost always from July to September. SOURCE

It's a rare occurance, and it mostly happens in the summer. The best thing to do is not stress to much, avoid allowing your dog to swim in untreated warm freshwater (SOURCE: see How Can Infection with Naegleria fowleri be Prevented?) and be careful while giving him a bath, and your dog should be fine. As noted in one of your links, there are many experts who believe that it is not possible for a dog to even get the parasitic infection in the first place. I asked my vet friend, and while she was unwilling to commit to the opinion that it was impossible, she stated there was enough differences in the canine nasal cavity from the humans, that she believed the incidence of infection would be drastically reduced.


I would say that the Naegleria fowleri bacteria does not pose a risk to dogs. Here in the south, hunting dogs drink in shallow ponds all the time while running through the woods, as well as dogs drinking out of lakes, rivers, and swamps, always at the shore, exposing their nose under water often. I have never heard of a dog dying from NF infection. Their immune system is not the same as humans, and cannot be compared to ours. I would say our dogs are safe.

  • 3
    Amoeba are not bacteria.
    – JoshDM
    Commented Mar 21, 2016 at 3:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.