Should my pup drink that? How to tell if water sources are safe.

Keeping your dog adequately hydrated is a common concern for most. Not only that, but the logistics of carrying enough water for both the pup and yourself can be challenging.This is especially true if you aren’t planning on running across naturally fed water sources. And what if you carry water for your dog but he doesn't drink it?   

(I wrote a two part blog post about dogs who don't eat or drink as much during trips and hikes, because a lot of us have this issue with our dogs.  All the different smells, sights, sounds and new adventures take priority over drinking and eating in some dog’s eyes. Click here to read  part two)

So, when we come across a nice looking stream, river crossing, or lake (er… pond?) we can breathe a sigh of relief when our pup willfully goes to the source and takes a drink. Right?

And my answer is (per usual) … it depends. Those of you who have been following for a while are probably sick of hearing “it depends,” but just hear me out. Most dogs will tolerate natural fed water sources. However, this will be highly variable depending on geography, environment, climate, and the dog himself. We need to look at this on a case by case basis. The goal with this blog post is to help you make an informed answer when it comes to questioning water quality and safety for your pup.


 Which water sources should you avoid?

Water sources that could be less than ideal or potentially harmful for your dog are puddles, stagnant water sources, small stagnant ponds, bodies of water near plants, factories, agricultural fields, and salt water sources. If at all possible, try to avoid these bodies of water. They tend to be more likely to carry harmful protozoa, bacteria, and potential plant vegetation that can be harmful to your dog. Also, if the water looks murky, has an odor, or muddy it is best to error on the side of caution and avoid it. 


Which water sources are okay?

Water sources that are considered to be more desirable are clear and clean moving streams, rivers, and larger ponds/lakes that are not stagnant. And once again, here we are talking fresh water not salt water. Consumption of too much salt water can be dangerous for your dog. Now, while we humans most certainly wouldn’t want to drink from these sources without some type of purification method or filtration, our dog’s gut does tend to handle it better. You do, absolutely have the option to filter the water for your pup. However, as long as the sources aren’t stagnant and don’t have any obvious algae or scum at the surface, they might be considered a safer option for doggy consumption.


What risks should I be aware of?

So, if you are reading this article, you are a responsible dog owner. Congratulations. Well what if you come across a nice-looking body of water and deem it safe for your dog to consume. What risks should you be aware of?

  • Giardia is a risk, although not typically life threatening in an otherwise healthy, middle aged dog. The typical signs of giardia are diarrhea or loose stools. While giardia gets the most press, natural water sources can be loaded with different types of bacteria, protozoa, and parasites.
  • Leptospirosis. Lepto is a bacterial organism that is passed via the urine or tissue of wildlife, like rodents and small mammals. Typically speaking, lepto is generally spread to dogs via contaminated water sources such as stagnant puddles and slow moving water. It is worth noting because lepto can cause significant and even deadly disease to your dog’s internal organs, and it can be transferred to people. Depending on the strain, letpo primarily causes kidney damage. However, it can also spread to the liver, spleen, eyes, reproductive tract, and nervous system. Fortunately, there is a vaccine available that is effective against 4 different types of lepto strains. If your dog comes into contact with a strain that is not covered in the vaccine there is little to no cross protection, however. The prevalence of leptospirosis is country wide, therefore vaccination should be discussed with your veterinarian if you are concerned about coming into contact with contaminated water sources.
  • Algae toxicity. Blue green algae are highly toxic to dogs during a bloom. These particular algae tend to grow best in stagnant bodies of water during hot and humid months. While one can decipher certain characteristics of the algae during a bloom, it is physically impossible to tell whether the algae is toxic or not without special analysis. When in doubt, it is best to steer clear of bodies of water that appear to have algae on the surface. There are two different types of toxins blue green algae can produce. One type is severely toxic to the liver, the other is a toxin that effects the nervous system. Even ingestion of the smallest amount can result in a very severe reaction and cause death in a matter of minutes to several hours. For cases who do make it to a veterinary clinic, there is no antidote and treatment consists of aggressive supportive care.
  • Toxicity. Different pond water additives, chemicals, fertilizers, etc could potentially be present in unfiltered water sources. The toxic effects will be highly variable depending on the chemical or toxin present. Generally speaking however, the body of water is usually large enough to where the toxin itself is diluted or in minute amounts. If this is the case, usually your dog can drink small amounts and be okay. The toxic dose of any substance will be highly variable and usually they have to consume a concentrated source to have ill side effects. 



How can I keep him from drinking from natural sources?

Keeping your dog from drinking ALL the natural water sources might be virtually impossible if your dog is off leash. Yes, keeping your dog on a leash will give you some control over what he puts in his mouth. But if your pup has the freedom to roam you can almost guarantee he will be drinking from where he pleases. If he has excellent recall you may deter him from stagnant puddles and dingy pond water, that is if you catch him in time or in the act.

So, if you want to control every little thing that goes in your dog’s mouth, including his water- you may want to consider keeping him on a leash.



Bottom line is, dogs will be dogs. Even on a leash it is near impossible to control 100 percent of their “life choices.” My intention with this blog post is never to scare or worry you, only to keep you aware of certain risks. The simple act of taking our dogs outside of our homes and into nature will expose them to a certain amount of risk. Our goal is to minimize these risks by increasing awareness and encouraging proactivity, all the while getting maximum enjoyment out of the experience of being in nature with our dogs.

 If you are on unfamiliar trail with unfamiliar water sources, perhaps it is best to keep your dog on a leash during your first time through. Or you could spend 10-15 minutes working on recall today. There is always some action you can take to increase your preparedness, and considering you read this entire blog post… I’d say you are far ahead of the curve. Keep it up.


And until next time, get out and explore but be selective of your water source ;)


Libbie Fort, DVM

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