SPF 50 Please!!!!!

“Dr. Telgen, I have a heifer that is losing all her hair!!!! I’ve never seen anything like it! She’s looks disgusting!” This is the phone call I had from a client this week. It was an 18 month old heifer that had been out on pasture.  When the dairymen went to check on them, he found this girl with her hide sloughing off various parts of her body. They brought her back to the barn and called me. I was headed there, for a fresh cow with a DA and while I was there, I checked on the “freak” heifer that is losing all her hair. 

Below are several pictures of various parts of the heifer. The bright pink tint to certain parts of the animal is salve they applied to keep the areas moist and try to relieve some of the irritation.  If you look closely, you will notice that the areas where there is black hair, and subsequently black skin underneath, appear to be normal. The areas of white hair/skin are the portions of the animal that are affected.  

Notice how the affected skin follows the line of the black hair.

The is a case of photosensitization, which only affects the white portions of the animal. Only the white portions are affected, because there is a lack of melanin in the skin, like there is in the black portions, and those white portions are most sensitive to sunlight. If you look closely at the pictures, you can see the areas where the skin is sloughing and perfectly follows the lines of the black hair. Other common areas affected are the mucocutaneous junctions such as around the eyes, nose, vulva and teats.  This heifer had lesions around her nose, but the eyes, teats and vulva were unaffected. 

Her nose seemed to be the only mucocutaneous junction affected.

The hide feels very tough and dried leather like. Just peels off with very little effort.

The affected areas went all the way down to her feet!

Cows are not the most discriminant eaters. This heifer had been out on pasture and most likely consumed a plant or weed that causes photosensitization.  As the animal metabolizes the plant that it has eaten, metabolites within the plant enter the body’s circulation and make their way to the skin.  When these animals are outside on pasture and exposed to direct sunlight, these “photodynamic substances” now in the skin, cause inflammation, irritation and essentially peeling of the skin.  It’s like being a red-headed, blue-eyed person out in the sun all day with no sunscreen, getting fried and then having the top layer of skin peel off.  Not that I know what that is like or anything….

As badly as sunburns hurt on me, I felt sorry for this poor heifer! Surprisingly, this heifer does not seem to be too affected by the situation. She has been brought inside the barn to be kept out of direct sunlight and is being treated with supportive care. She has received some pain medicine, and as I mentioned, the salve is being applied to help keep the area moist. However, she was running around the pen and eats and drinks like nothing is wrong.  Unfortunately, the damage to the skin has already been done and there is nothing we can do to prevent the rest of the affected areas from sloughing.  As long as she does not suffer from bacterial infections of the exposed, raw skin, she has the potential to fully recover and go on to be a productive animal.

There are about 30+ plants, molds and chemicals that can cause photosensitivity like this. The most common plants are St. John’s wort and Buckwheat, both of which are pictured here.  Other common plants that cause this primary photosensitivity include, Bishop’s weed, Dutchman’s breeches, wild carrot, spring parsley, prairie lily, smartweeds, perennial ryegrass, Burr trefoil and even alfalfas and clovers. I would have to research what most of these plants/weeds look like, but if you have animals (cows, horses, sheep or goats) out on pasture and notice some of these plants, it may not be a bad idea to remove them. 

 

Buckwheat

St. John's Wort

Not all animals are affected. The other heifers in the pasture with this one all seem to be fine.  It is also pretty much impossible to know which animals are going to suffer from such a disorder, until you start to see signs of the skin sloughing.  If only they made sunscreen for cows, that would be easy to apply and actually work through the hair!