sheep with swollen ears

[Mark Billadeau]

We've had a couple of lambs come up with swollen ears (both ears). There were no sores on these lambs and no other signs of injury or illness. We suspect they ate some thing that caused this reaction. What plants can cause this?

 

Mark

[Mike Neary]

Mark,

 

I would suspect photosynthesization (spelling?). especially if they are whitefaced. There are a number of plants that can cause this, I'm not familiar with all the plants in your area, but here alsike clover is always a prime suspect. I imagine there are a number of weeds that can casue it also.

 

If they are in bad shape, you can put them in a barn, out of direct sunlight. I'd probably give them a dose or two of banamine also (1 ml/100 lbs bwt). This usually occurs in spring or early summer, but they must have gotten into some weed or plant that has triggered it, along with the unusally warm and sunny fall we've been having.

 

If it is this, you probably will see some scaling and flaking of the skin on the ears as time passes.

 

You can google this condition, it may also have some plants native to your area listed that contribute to it.

 

mn

[Shoofly]

I've had sheep get this. The banamine does make them feel better. There's some weed around here that causes it but i'm not sure what it is. I've had them get it from eating in an area i don't normally graze as well as from some hay that was baled not too far from that area. It's usually confined to only a couple of sheep and putting them in a shady area makes them feel better as it limits the amount of swelling. I have had a couple where the ears got swollen enough to get weepy and oozy.

[Mark Billadeau]

The first lamb (brown katahdin) only had swollen ears which got better in a few days. The other lamb (white cheviot x katahdin) was found before we left for the last trial and we returned after dark last night so I have not inspected her. What photosensitization info I've found so far talks about reaction on bare parts of the sheep. The brown katahdin has a slick coat and there was no reaction on the nose, face, or other body parts except the ears.

 

I will look some more for plants in our area that can cause photosensitization.

[Shoofly]

I've had hair and wool sheep both get it, only on the ears.

[Mike Neary]

Mark- the ears are typically the first place you will notice the condition, primarily because they have the most exposure to sunlight. The face and nose also oftentimes get scaly, reddened skin, often resulting in some hair loss. I've never seen it on the body, but I don't have hair sheep.

 

I don't consider this a real threatening condition, especially if the weather turns more normal. The biggest issue I've seen with it was a producer I know had Dorset sheep that he liked to breed in the spring for fall lambs and one year he had a bad run of this in the spring and low breeding results. If the ears do get as swollen and weepy as Robin suggests, then some time out of the sun is probably wise. If they are slightly swollen, and not being exposed to a ram, I'd probably just watch them close and if they start to get worse, take action.

 

mn

[Mark Billadeau]

I've emailed our extension agent (Susan Schoenian) for info on local plants that are known to cause photosensitization.

[SouthOfSouth]

I looked up my copy of Hungerford - not the most recent edition. According to this edition of Hungerford, photosensitization is the external manifestation of liver damage thought to be caused by a fungus, Pithomyces chartarum, growing on the pasture. Hungerford quotes one paper as saying that only 8 ewes in a flock of 180 had facial lesions at slaughter, but 60% had liver lesions. He says that it commonly occurs when stock have been exposed to recently dead pasture in humid conditions. The symptoms are commonly seen in young sheep, but pregnant ewes are particularly adversely affected.

 

Hungerford lists the following plants as "causing" photosensitization. Alsike clover, burr medic, broom corn millet, caltrop or yellow vine, crowfoot, hairy panic, heliotrope, japanese millet (only sometimes), kale, lantana, lucerne, lupin, paddy melon, panic grass, panicum sanguinale, rape, rye grass pasture, St John's wort, subterranean clover, summer grass, trefoils, yellow vine. I have also read authorities recommending against using kikuyu in pasture, because of its association with photosensitization.

 

Photosensitization can occur in cattle, Although I have not seen any reference to it in cats, my mother's two elderly Siamese cats developed photosensitization-like symptoms after spending a lot of time walking through long, damp kikuyu and rye grass. The symptoms abated after the grass was removed.

[ThunderHill]

I haven't had personal experience (yet) but I've heard of St. Johns Wort causing similar symptoms. Recently I have noticed something that looks like St. Johns Wort growing all through my pastures. It's normally an edge-of-the-woods plant, but maybe with the record-breaking rains it's been dark enough for it to spread beyond its usual range. Even out in the open where it's usually sunny and bright.

 

I hope your lambs will be better soon, even if you never figure out what's caused it.

 

Liz S in Dark Damp Dismal South Central PA

[OurBoys]

I've emailed our extension agent (Susan Schoenian) for info on local plants that are known to cause photosensitization.

Mark, I'd be interested in what Ms. Schoenian has to say if you don't mind sharing.

[Mark Billadeau]

I'll will post the info when she responds. She is often slow to respond due to her traveling.

[Mark Billadeau]

Sue's response was she didn't know off hand and then copied a segment from a CA website on photosensitization.

[Mark Billadeau]

We've had a couple more sheep show up with signs of photosensitization after being in a particular pasture surrounded by woods. When I have time I guess I'll have to survey the wooded areas around this pasture.