Re: What effects might cows suffer drinking Calcium Chloride?

Krystal, thank you for your very interesting question.

We toxicologists have an old saying – “dose makes the toxin.” In other words, just because something is toxic does not necessarily mean that a single exposure is bad. Now you’re probably thinking, “Jeeze man, read the question, I said repeatedly!” So why am I talking about a single exposure? The reason why is because depending on various complex variables these repeated episodes may in fact be more like a single exposure, then again, they could be like a repeated exposure.

So what constitutes the dose in this case? That is one of those odd, and complex variables. We usually take a dose to mean a certain amount of substance per kilogram body weight of the animal (i.e., 5 mg/kg tetracycline = this would be 5 mg of tetracycline per 1 kilogram of animal body weight; another example would be 5mL/kg, this would be 5 mL of substance per kilogram of animal). In this case, the dose is going to be variable depending on the concentration of CaCl2 in the water, and the amount of water consumed.

So what else will determine if there is toxicity? The state of the cow is one major determinate. Is the cow an adult or a calf? Is the cow hypocalcemic (hypo = low, calcemic meaning a state dealing with calcium; hypocalcemic = a state of low blood calcium). Is the cow experiencing some kind of salt deficiency or other dietary deficiency? Is the cow in any kind of disease state?

So, assuming the cow is a normal adult cow, if the dose is high enough we could see some rather bad effects as a result of ingesting the CaCl2. I should note here that anything in excess is most likely toxic, not just CaCl2. But if the dose is not that high, or if the cow is not hypercalcemic, there should be no adverse effects.

If the cow is a young calf it may not have a very well developed Ca++ buffer system (Ca++ being the calcium ion), and may experience a whole host of bad effects. Some of these might include muscle tremors, abnormal bone growth, and abnormal salt homeostasis.

However, I highly doubt we would see too many bad effects from CaCl2. The reason is that Ca++ is not readily absorbed by the digestive system. Ca++ absorption occurs in the small intestine and is under the regulation of Vitamin D (actually Vitamin D metabolites). Without getting into the chemico-physico dynamics of the system, trust me when I say it’s just a tad-bit complex. To say the least, it would take a great deal of Ca++ to be absorbed to be able to overcome the Ca++ buffer system in the body, and even then, it would still take a great deal just to push the concentration gradients to the point where Ca++ would be easily absorbed by the small intestines.

That having been said, I would predict that these cattle are in more danger of falling into the pond and drowning than they are from seeing any kind of overt toxicity from ingestion of this water. There are probably more harsh chemicals in that water that are going to be more toxic at lower levels.

I wouldn’t expect the acid to do too much to the cattle. The reason why is because it is so dilute to begin with, and now is being further diluted by the pond that the water is not that acidic (the water, being in a “natural” environment has within it what is called the carbon acid/base buffer system, which can buffer most acid and base “attacks” upon it), so the water is probably still rather neutral (especially with all that lime in there).

Here again, the lime shouldn’t be too much of a problem. The reason why is because the lime is part of the natural buffer system that lakes and streams (more lakes and ponds than streams) use to buffer attacks by acids and bases. Lime is also rather inert, and would most likely pass through the digestive system rather nicely. Some part of it will become dissolved, and would get passed on into the blood, but would act as a further buffer within the blood plasma (blood has some natural buffering capacity, and part of it uses the carbonate and bicarbonate ions which you find when you dissolve lime in water). In very high dose cases of lime “poisoning”, one could expect alkalosis (alka = alkaline, or having a basic pH; alkalosis meaning having a blood pH higher than 7.5 or 7.45). But here again, the body has a great capacity to repel that kind of chemical insult, so a toxicity due to lime is very rare.