Ask the Vet

Water Quality and Capacity

Allowing cattle access to farm ponds can be a negative for their health and water quality. (DTN/Progressive Farmer photo by Claire Vath)


We have a couple of farm ponds that are the only sources of water on the pastures they are in. We also fish in these ponds. Some years, especially if we have a dry fall, they get muddy, and we see a lot of algae. I worry these algae may not be good for the cows or the fish. How big of a problem is this?


In the Deep South, farm ponds are a common source of free and readily available water and recreation. But you are correct, they are a two-edged sword.

Depending on the size of the pond, its design and water flow, cattle can destroy fish habitat and reduce the pond's water capacity and water quality. All of this can have a huge negative effect on cattle health and performance.

With unlimited access to a pond, cattle will stand in the water and eliminate in it. This can be a source of many diseases, including leptospirosis. In some areas, liver flukes can also infect cattle. The moist areas around ponds are a source for coccidia and intestinal worms. Foot rot can also be a problem since the hooves and interdigital skin are softened by standing in water for long periods of time. The moist ground around ponds is a perfect place for bacteria that cause foot rot to survive.

Over the years, I have seen several snake bites that most likely happened around a pond. And we have not even discussed the impact on the fish or the algae problem.

While most algae are not toxic, some species of blue-green algae can be dangerous or even fatal to pets, people and livestock. Cyanobacteria are not algae but rather bacteria that contain chlorophyll. Some species can produce neurotoxins that lead to muscle tremors, difficulty breathing, seizures, profuse slobbering, diarrhea and rapid death. They can also lead to a buildup of hepatotoxins, which can cause sudden death or liver failure. Liver damage can lead to photosensitization, a skin condition causing nonpigmented areas of skin to crust and peel.

So, what can you do? One option is to fence the pond off and then gravity-feed a water trough below the dam. If this is not possible, a pump could be used, but this requires a power source. The last alternative is to only allow access to a small area of the pond where a heavy-use area has been created. You may be eligible for cost-share dollars to help pay for systems such as these through the USDA Natural Resources Conservation Service.

Clean, fresh water is the most important input for any livestock operation and providing it should be a top priority. I assure you it will pay dividends many times over. And the fish will appreciate it, too.


Editor's Note: Please contact your veterinarian with questions pertaining to the health of your herd or other animals. Every operation is unique, and the information in this column does not pertain to all situations. This is not intended as medical advice but is purely for informational purposes.

Write Dr. Ken McMillan at Ask the Vet, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email