Borehole and Tank Water: Is It Safe for Pets?

Usually fine, occasionally not

Most borehole and rainwater tank supplies are perfectly safe for animals. The problems are specific and worth knowing about rather than a general reason for concern.

Dogs and cats are broadly as sensitive as people to what matters here, and in some respects more so because they drink from wherever water collects.

What to test for

• Nitrates, particularly on agricultural land or near old feedlots
• Coliform bacteria, especially after heavy rain or where a septic system is nearby
• Heavy metals in old mining areas, which includes large parts of Gauteng and the North West
• Fluoride, which is naturally high in parts of the Northern Cape and Limpopo
• Total dissolved solids and hardness, which affect palatability more than health

A basic potability test through an accredited laboratory costs a few hundred rand and is worth doing once when you move in, then after any major change.

Tank maintenance

Rainwater tanks collect whatever is on the roof: bird droppings, leaf debris, dust. A first-flush diverter that discards the initial runoff makes a large difference.

Keep tanks fully covered and screened. Open tanks are a drowning risk for cats and small dogs, and a mosquito nursery.

Clean tanks periodically and check the inlet screens after storms.

The green pool and stagnant water problem

Dogs drink from wherever they find water, including a neglected pool, a stagnant Jojo tank overflow or a puddle in the yard.

Blue-green algae blooms in warm standing water produce toxins that can kill a dog within hours. If water is green, scummy or smells bad, fence it off.

Leptospirosis is transmitted through water contaminated with rodent urine. Standing water on a property with a rat population is a genuine risk and is a reason to discuss the vaccine with your vet.

Simple practices that help

Wash bowls daily with soap and rinse well. A biofilm builds up within a day or two and is the most common source of an off-tasting bowl.

Provide fresh water in more than one place. Cats in particular drink more when water is away from their food.

If you are on tank water and it has been a dry season, be alert for a change in taste or smell. Dogs and cats will often stop drinking before you notice anything.