Can Well Water Make a Dog Sick?


Dogs can become sick if they drink well water that is extremely hard (high in calcium and magnesium), has high nitrate levels, or is contaminated by parasites, blue green algae, or other pollutants.

We don’t have to tell you how important water is to your pooch.  A private well can be the perfect solution to most of your water needs. But can your dog drink well water? What if it makes them sick?

This article will discuss in detail what is in well water that may be harmful to your dog, what symptoms to look out for, and what you can do about fixing it. Oh, and watch out for a couple of well-intentioned puns along the way.

Well Water and Dogs

Many people think that if they can drink their well water, then it’s fine for their dog too. But there’s a lot more to it than that.

Let’s cover the basics first.

Just like us, your pup’s body is more than 70% water. This means that your dog needs water for several functions. From regulating body temperature and maintaining skin texture to flushing out toxins and ferrying nutrients across the body, your pooch needs H2O as much as you do.

Additionally, you need to be extra careful about your pup’s water intake because canines don’t sweat as much as humans do. Dogs regulate their water level by panting and sweating through their paws. While most dogs are always enthusiastic about a quick splash-n-drink, here’s what you need to know about well water and your dog.

Well water comes straight from the ground. Simply put, it is untreated groundwater. Earth aquifers act as natural filtration systems, but that doesn’t mean you can fill your dog’s bowl with well water without thinking twice.

Not all well water is equal. The quality of your well water depends on a lot of factors – the aquifer rock type, natural and man-made contaminants, the filters you use, and the condition of the well itself.

More importantly, the quality of water in your well is your responsibility. The government – specifically, the Environmental Protection Agency – does not regulate well water safety standards. This means that you must make the call when it comes to how clean your well water is and if it’s suitable for your pets.

Well Water Contamination

The quality of well water will depend on where it is coming from, what contaminants is may pick up underground or from the surface, and whether you inspect and clean the well when necessary.

Well water can quickly become contaminated by animal waste, nearby sewers, surface water runoff, algae blooms, and parasites and micro-organisms growing in the well itself.

Antifreeze and cleaners from your own property or a nearby contaminant source can also seep into your well. Some wells can also contain potentially dangerous levels of arsenic, radon, and lead. Arsenic and radon can cause cancer, while lead can lead to seizures and brain damage.

Parasites in well water and diarrhea

Single-celled organisms such as Giardia found in well water can cause diarrhea in dogs. This parasite is found in animal (and human) feces and is water-borne.

Salmonella, cryptosporidium, and E-coli can also be found in water and can cause vomiting and seizures in dogs.

Well water may contain parasites that can cause serious illnesses to both you or your dog(s).

Wells can be a breeding ground for blue-green algae, which is toxic to your dog and other pets.

For more information about algae in wells, how to detect it, and how to get rid of it, read our article titled how to quickly get rid of algae from well water.

Hard Water and dogs

Water from most wells in the U.S. is usually ‘hard.’

Hard Water is classified as having a dissolved mineral content of 61-120 mg/L.

Extremely Hard Water is classified as having a dissolved mineral content of more than 180 mg/L. 

Hard and Extremely Hard Water contains a high level of dissolved minerals – mostly magnesium and calcium. These minerals are picked up as the water passes through mineral-rich rock and soil before reaching your well.

Extremely hard water is bad for your dog. A study by pet insurance company Trupanion suggests that extremely hard water can cause urinary tract infections, stones, incontinence, and cystitis. What’s more – female dogs are 2.5 times more likely to be affected by extremely hard water than male dogs.

There is little harm for dogs to drink hard water once in a while – it doesn’t pose any instant health risks. Magnesium and Calcium are necessary nutrients for dogs. However, regular consumption of high levels of magnesium and calcium can be harmful to dogs, as discussed below.

Magnesium and dogs

Magnesium that is consumed by dogs at high concentrations for extended periods of time can cause mild to severe illness and can even be life-threatening.

Dogs will often form bladder stones

Dogs that consume high levels of magnesium can also damage their nervous system and heart. Typical symptoms include:

  • Slow and ineffective breathing
  • Weakness
  • Paralysis
  • Cardiac arrest
  • Coma
  • Death

Bladder stones are also common in dogs that drink high magnesium content water.

Extremely hard well water is not safe for your dog to drink.

Calcium and dogs

Calcium is common in hard well water and can be harmful to dogs when consumed regularly at high concentration levels. Although calcium is an important nutrient for dogs, it can also affect bone growth and development, especially in lager dogs.

Calcium can cause the progression of kidney disease in dogs. Dogs that regularly consume high levels of calcium may also develop bladder stones.

Nitrates and dogs

If your well is located close to a farm or a factory, you’re more likely to find nitrates in your water. Nitrates may seep into your well either via the underground aquifers or as surface water runoff.

Animals should not drink water that has nitrate concentrations above 10 mg/L. Nitrates can cause oxygen uptake problems in your dog. This is worrisome especially with older dogs that have other illnesses. Besides, it can affect the health of children in your family too. This means that nitrates in well water are a no-go.

Phosphorus and dogs

Phosphorus is also common in well water when contamination occurs from nearby agricultural areas. Phosphorus in wells can cause algal blooms, which are both hazardous to both you and your pets.

Phosphorus can be harmful to dogs if consumed in high quantities. It can have a negative effect on dog’s bones, particularly during the growth phase of larger dog breeds.

High phosphorus levels can also cause an advancement of kidney disease in dogs, and can cause the formation of bladder stones.

Signs That Your Dog Is Sick From Drinking Well Water

We get it – sometimes, regulating an overenthusiastic pup’s water intake can be quite ruff.

If your pet drinks contaminated well water, watch out for any signs and symptoms that they are sick.

Diarrhea and an unnatural poop cycle are usually the first signs of a water-borne illness. This can be accompanied by vomiting and tiredness. 

In rare cases, there may be neurological problems like seizures and tremors. This is more common in dogs that have pre-existing conditions, are prone to allergies, and older pets.

If your pup seems lethargic, sleepy, or in a semi-comatose state, this could also be a sign of water-borne illness. They may drool unnaturally, or their saliva may smell weird.

In all these cases, seek medical help immediately. Treatment usually ranges from immunity-boosting drugs and medicine to combat parasites.

Purifying Well Water For Dogs

Many people on well water opt for a simple under sink filter combined with a water softener. Others prefer an RO purifying system, which can also provide great results.

A Clean Bowl

Regardless of what water your dog drinks, you must clean their bowl frequently, especially if you leave your dog’s bowl outdoors. Change the water twice a day. Wash your pup’s bowl every day. It takes only a few minutes, and your pet’s health will thank you.

The bowl may become moldy. This leads to nasty bacterial growth that can seriously impair your pooch’s health. A good stainless steel bowl will be more durable and less prone to bacterial growth. Glass or ceramic bowls are also good.

Another great option is to use a pet drinking fountain. Some even have inbuilt filters.

Testing Well Water

Wells must be properly monitored and maintained.

So, how can you make sure your dog doesn’t get sick from well water?

Testing your well water regularly is the best way to ensure the safety of your family and your fur baby.

The quality of well water changes with time. We recommend testing your well water at least every year. Additionally, watch out for any changes in the appearance, color, taste, and odor of the water.

Frequently Asked Questions

Can Dogs Drink Too Much Water?

Dogs can get sick if they drink too much water. This is common, especially in the summer months. More often than not, getting sick from drinking too much water can be a sign of something more serious. In this case, we recommend visiting your vet.

Can Dogs Drink Bottled Water?

Many advice against bottled water for both you and your dogs. Bottled water is terrible for the environment and contains harmful toxins as well – particularly BPA. BPA can cause hormonal issues and even cancer, so that’s a hard pass!

The Bottom Line

Treat your dog just like you would a member of your family. Do not compromise on the quality of your well water when it comes to the health of your pooch. Here’s the golden rule – don’t give your dog water that you wouldn’t drink yourself. All it takes is some good water and love to stay paw-sitive!

Russell Singleton

Russell has a Bachelor of Science (Environmental and Marine Geoscience) with Class I Honors. He is currently completing his doctorate in science and is passionate about all earth processes, especially isotope geochemistry and paleohydrology.

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