The Accidental Smallholder Forum

Livestock => Sheep => Topic started by: NewLifeOnTheFarm on August 06, 2019, 08:10:23 am

Title: Photosensitivity
Post by: NewLifeOnTheFarm on August 06, 2019, 08:10:23 am
Hi all,

We brought the sheep in last night for crovecting, feet checks, etc, and found a white Shetland lamb, about 4 months old, with extremely sore but healing ears. They look as if they have had terrible sunburn, to the point the tips have sloughed off. They had been in very long grass until yesterday which is why we may have missed any early signs.

A quick search shows it was almost certainly photosensitivity, and we are assuming she has ingested some weed. We don't have ragwort, but we do have cow parsley or Queen Anne's lace, among many different clovers.

We have never had any others with this problem, and just wondered what others experiences were. She is now inside, has had antibiotics, pain relief, purple sprayed to the hilt, and having some well deserved TLC.

Thanks
Title: Re: Photosensitivity
Post by: Fleecewife on August 06, 2019, 12:11:42 pm
I don't think cow parsley would be a cause of photosensitivity, more likely something she's picked up from a hedgerow, or overhanging from someone's garden?  I can't remember offhand which plants cause photosensitivity, except of course giant hogweed.  To your treatment I would add a copious slathering of sunblock factor 50, or clean mud if you haven't got that.
Title: Re: Photosensitivity
Post by: Nelson International on August 06, 2019, 12:39:25 pm
St. John's Wort(?) is I think the major cause of photosensitivity in some parts of the country. Is cow parsley a relative of hogweed? They look pretty similar don't they? My mother in law had a brush with some form of hogweed just this summer and it was worse than bad sunburn - really nasty looking burns.

I think an alternative cause of photosensitivity can be a lack of cobalt(?), so when I had a couple of cases I started giving the sheep a cobalt drench. Allegedly there's a lack of it in the grazing around here so most farmers go for a bolus or something. But I've stopped doing it and not yet had another case, so maybe it was diet after all.

We had 2-3 sheep lose the fur on their ears and show some scabbing. I put sudocrem on their ears (and in one embarrassing miscommunication, my wife's most expensive skin cream) and made sure they had good access to cover. It ceased to be a problem over a few weeks and hasn't recurred.
Title: Re: Photosensitivity
Post by: SallyintNorth on August 06, 2019, 01:44:38 pm
Bog ashphodel is one culprit.  Usually on marshy / wet ground. 

Title: Re: Photosensitivity
Post by: NewLifeOnTheFarm on August 07, 2019, 07:53:25 am
Thank you all. We don't have any giant hogsweed on our land, and neither of us can recall seeing St John's Wort prior to mowing. I wish I knew what it was! It is an isolated case so hopefully last we see of it.

I did read on a New Zealand page, that Cow Parsley could cause it, but not many sources suggesting same.
Title: Re: Photosensitivity
Post by: SallyintNorth on August 07, 2019, 09:19:23 am
If you don’t have the culprit plants, might be worth giving them a mineral drench with cobalt and selenium in it, or whatever your vet or the local agri merchant’s animal health folk say are the likely defiiciencies in your area. 
Title: Re: Photosensitivity
Post by: Fleecewife on August 07, 2019, 12:28:49 pm
There seems to be a whole load of confusion surrounding Cow Parsley, Anthriscus Sylvestris, known by many common names.  Visually it is easy to confuse with Poison Hemlock and Fools parsley.  In America, there is a plant called Spring Parsley, Cymopterus ibapensis, which does cause photosensitivity, but it is a plant I have never seen in the UK.  It may though explain the references to photosensitivity and the word Parsley, just confusing us.  This is where the Latin names come in to differentiate.


Cow Parsley, Anthriscus sylvestris, does not cause photosensitivity.


Giant Hogweed, Heracleum montegazzianum, described as Britain's most dangerous plant, whilst also an umbelifer, with big, white flat groups of flowers, is very different to Common Hogweed, Heracleum sphondylium also known as Cow Parsnip.


Giant Hogweed, which grows to about 5' tall, is unmistakable. It is a naturalised non-native plant, which causes severe burning and blistering of the skin on contact then exposure to sunlight.  You would certainly know if you had it in your pastures  :o .   


Common hogweed, on the other hand, is native to the UK and does not cause any toxicity at all, in fact it's what we used to collect from the verges for our rabbits when we were kids.


If you google these various plants without specifying UK, you will get American sites, and American plants are very different in some instances to UK plants.  For example, their main itchy rashy plant is Poison Ivy, which doesn't grow here in the wild


Other plants which can cause photosensitivity include Euphorbia, Cuckoo pint, Oleander, Mezereon, St John's Wort, buckwheat, RAGWORT,  and RUE - I can't go near Rue!  Apparently Leyland Cypress is a culprit too.


http://www.horsedvm.co.uk/disease/photosensitization/ (http://www.horsedvm.co.uk/disease/photosensitization/)   This is about horse photosensitivity but is worth a read.