Hair loss in cattle

[sdrancher]

Hi

Does anyone know what else could make a cow lose hair in patches (perfect circles) all over her body? Initially we thought it could be lice or ringworm, but others in the herd aren't getting it and we use dectomax pour on for lice, etc. She never seems to come out of it. This has been the 2nd year that she has this condition. It doesn't seem to irritate her and she seems perfectly normal. I have seen the pictures of ring worm, and this does look similar, but the circles are perfectly round with smooth edges. The patches are all over... sides, brisket, legs, etc and probably close to 4-5 inches in diameter. I said this is the 2nd year she's had it, but it never seems to go away, so it is not like something she gets, gets over, and then gets again. It is like she always has it.

Thanks for the help!

 

[Victoria]

Is photosensitization a possibility? That can create hair loss in patches - usually starts by the udder.

 

[sdrancher]

Hi
Yes I guess that is a possibility. Actually, that is what I thought it was at first because we had another cow with it about 3-4 years ago, and it does look similar to what the other cow had. The reason I didn't pursue that any further is because we were told that photosensitization occurs only on lighter colored animals and this one is all black. Just had time to do some research, and found a Merck book online that says one type of it can also occur in black cows.

It doesn't appear to bother her. She just had a nice little bull calf and is taking good care of it!