If you use refillable water bottle and think you’re drinking pure water, then you have to study this new research that claims your dog’s toy is better than your bottle in terms of bacteria. Results could be worrisome for those who use water bottles for weeks without washing them, suggested the research.

To determine how many bacteria are living on a water bottle, a website, called Treadmill Reviews, collaborated with EmLab P&K and tested about one dozen water bottles for four kinds of tests: screw-top, slide-top, squeeze-top, and straw-top. The bottles in the study were of athletes who used them for about a week without washing them.

The tests’ results showed that even reusable drinking containers are not safe, announced Treadmill Reviews. Researchers found over 300,000 colony-forming units per square centimeter, it added.

The highest germ content was noticed in slide-top where over 900,000 colony-forming units per square centimeter were present. These water containers also had gram-positive cocci, which may cause health problems like pneumonia, skin infections and blood poisoning.

Squeeze-top bottles were with 162,000 colony-forming units per square centimeter, while screw-top containers had less than 160,000 colony-forming units per square centimeter, stated the research.

According to the website, drinking water from such containers is more harmful than eating from a dog’s container. The straw-top bottle tests were a big relief as the researchers found just 25 colony-forming units per square centimeter. The low numbers could be because water there drops to the straw’s bottom and doesn’t stick.

After seeing the results, the site has advised people to choose straw-top bottles. “We also know that when it comes to water bottles and bacteria, stainless steel is a better choice than plastic. Additionally, water bottles without crevices and tough-to-clean spots are less likely to host germs”, it added.

A report published in GEO informed, "Researchers in the US have discovered those bottles could potentially make you sick. The discovery came after health experts swabbed 3 bottles each of the four types of reusable bottles people most commonly used; the slide-top, the squeeze-top, the screw-top and the straw-top."

To put things in perspective, the average toilet seat has about 27 CFU/sq cm. Yes, let that sink in for a minute, but don't be quick to boycott reusable bottles altogether just yet. Bacteria are present all around us, some are harmless some are beneficial while certain others can make you fall sick.

While reusable bottles have high presence of potentially harmful bacteria, instead of tossing the reusable water bottle, maybe its time to start giving that bottle a hot wash everyday instead of letting it sit half full in your gym bag or your child's school bag.

According to a report in Yahoo by Natasha Preskey, "Research by treadmillreviews found that that water bottle you've been lugging around in your hand bag for weeks is covered in nasties and drinking from it could be as unhygienic as licking your loo."

The grimiest bottle had 900,000, making it more germ-ridden than a toilet. The average pet toy only has 2937. The grim state of our bottles is caused by not washing them, sweat and ordinary daily germs. To make matters worse, 60% of the germs found were able to make people sick.

Some water bottles were found to be worse than others, with slide-top bottles being the most germ-ridden, straw-tops the cleanest and screw-tops somewhere in between. Stainless steel bottles were also found to be more hygienic than plastic bottles. All in all, it's probably time you binned that trusty Evian bottle. Go on, buy yourself a Thermos flask. You're an adult now, after all.