What causes black hair to fade to brown?

Calypso is a primarily black mixed-breed dog (probably Aussie & Shepherd) with some areas of black hair that are turning slightly brown or copper-colored. His skin and coat are healthy and shiny, so we know it’s not an infection or unusual endocrine disease. What, then, could be causing Calypso’s coat to fade? Let’s consider

• genetics,
• hair loss,
• sun bleaching,
• drugs, and
• food,

and see what is most likely to cause this change.

Genetics that changes black hair to brown
I don’t suspect Calypso’s change in hair color is due to genetics. There is a genetic tendency called aurotrichia (gold hair) in some dogs, but usually these are Schnauzers

Hair loss
Let’s check if Calypso has two coats, an outer coat of long guard hairs, and an undercoat of a different color. If Calypso has black guard hairs that have been shed to expose a brown undercoat, we could have an apparent coat color change. But, that’s not happening as Calypso’s bronze hairs are long guard hairs, all the same length and texture.

Sun bleaching
Can Calypso’s bronzing be due to sun bleaching? No. This fella doesn’t spend hours outside on the deck, and is usually walked early in the morning or later during the day when the sun isn’t bright. And, if it were due to sun bleaching, we’d see the effect mostly on the topline. Calypso’s bronzing is in small areas, a little off the topline, over the ribs.

Drugs that change hair color
Next, we check whether Calypso’s change in color could be due to drugs, since some drugs affect the skin and hair. Calypso isn’t on steroids, antifungals, chlorambucil, or antacids, such as Pepsid. So, no drugs commonly known to change coat color are responsible for this bronzing.

Foods affecting coat color: copper, tyrosine, zinc
Copper
Let’s check the diet. A deficiency of copper or of tyrosine can cause bronzing. Is Calypso getting healthy portions of the following copper-rich foods--oysters, shellfish, beans, nuts, kidney & liver, whole grains, sesame seeds, barley, turnip greens, and molasses? Ok, most of us can’t afford healthy portions of oysters and shellfish, but we trust Calypso is getting some of the other copper-rich foods, especially liver.

Tyrosine
Is Calypso getting healthy portions of the following tyrosine-rich foods-- tofu, chicken, turkey, fish, avocados, lima beans, yogurt, cheese, bananas, and avocados? We suspect he is, because he receives home-made chicken stew frequently.

Zinc
What if Calypso is getting healthy amounts of copper-rich and tyrosine-rich foods, but he is getting even more zinc-rich foods? Because zinc interferes with copper absorption, zinc-rich foods can decrease the amount of copper he is able to absorb. Zinc rich foods include: oysters, legumes, cereals, & meat, such as lamb, beef, poultry, and pork. If Calypso is getting more of the zinc-rich foods than copper-rich foods, we may have an imbalance that causes bronzing of black hairs.

In addition, feeding milk and eggs interferes with copper absorption.

What should Calypso’s family do?
Rather than add vitamin or mineral supplements, Calypso’s family should vary the food he’s receiving and increase the amount of copper-rich foods. If the bronzing continues, Calypso should be given enzymes so that he can absorb more of the copper he’s being fed. If this doesn’t work, we will add a mineral supplement, and do some lab work to ensure his organs are all functioning properly.

Black hair fading to brown is another example of how important food is to pet health.

As always, food should be part of our solution to pet health issues.