Author Topic: Orf in lambs (Read 3580 times)

Helen Wiltshire Horn · « **on:** April 25, 2014, 07:16:50 pm »

It looks like 2 of my ewe lambs have orf and Mum has a few pustules on her udders but not on her teats (I gather that the lambs will have caught it from Mum even though they seem to be more adversely affected). There seems to be two schools of thought - one to seperate and then vaccinate those that haven't got it 4-6 weeks before lambing and the other approach of letting it runs it course though my (very small) flock. The first seems the most sensible as all of mine have now lambed and the vet said that he wouldn't have thought that even a bad case would kill or cause serious harm. The affected lambs are feeding and looking fine and their faces look better today. Mum shows no signs of mastitis thougth I was advised to turn her every 3 days or so to have a proper check. Any other advice? Am I mad in thinking it would be good if others got it and they developed a natural immumity (all lambs are healthy and more than 3 weeks old). Any thoughts?
Helen

FiB · « **Reply #1 on:** April 25, 2014, 07:30:01 pm »

I can't get my head around it.... I have 12 ewes and 20 ish lambs last year and this.... Both years 2 have got it on mouth, only this year has it caused a prob (pet lamb limited drinking for a couple of days)... Have let it run it's course and no secondary infection needing ab.... I think my whole flock would be deemed to have it? So can't understand how vaccine would work in a flock where it is already present? Just praying I didn't get it before I started wearing gloves

Hoping you have easy ride too, fi xx

Helen Wiltshire Horn · « **Reply #2 on:** April 25, 2014, 07:48:35 pm »

When I spoke to vet he said that at one time or other he and all his colleagues had had orf on their hands so pretty much resigned as I picked a lamb up and said "what's this?' before thinking more coherently! I am sure I am going to get it and am dreading it. I also am not sure about vaccinating. Vet was very certain it was "self-limiting" and would never kill a healthy animal. Not sure how long sheep will develop an immunity to it but I can't see any up-sides of seperating my flock at the moment. Am I missing something?
Helen

pgkevet · « **Reply #3 on:** April 25, 2014, 07:50:26 pm »

Don't take anything I say as professional advice since it's 40yrs from my sheep lectures. this is also not a commercial holding. But I had reason to make enquires and read a bit about Orf after my OH 'rescued' 3 orphans with 'just a touch' of Orf last week. They had apparently been vaccinated also

I had a long chat with local sheep vet since i have 2 other sheep and my ewe dropped and rejected an unexpected lamb the same day the rescues arrived.

Remember that orf is a poxvirus and the vaccine is pretty crude: the idea of it being to kickstart a response in the patient bcause it's not responding well enough to the virus it alredy has. It's alsoa disease that will vary greatly in degree from indivdual and also can contminate your soil and lambing areas.

A lot has to do with how many sheep you have and your land. A high stocking desity and thistly/thorny land will lead to more chances of cases popping up and then spreading. Decontaminating a lambing shed ought to be possible.. with the right type of shed and enough effort - but if it's just going to get recontaminated with a large throughput then not worth it.

In my case i have my home grown lamb isolated from contact but able to see the three affected ones durig the day. But overnight the three are in the barn and solo is in the house. my whole flock of six to be has 10 acres to play on so stocking density isn't an issue and with the vaccine itself possible causign reactions.. and the need to buy a 50 dose bottle for three sheep I have decided just to wait and see.

In your case assuming you have a decent number of sheep ad just this one isolated ewe and lamb I'd also be inclined to sit back a while - dependant on whether you could, say, use a different place for further lambing, adjust stck deisty, use a different field if you have them etc. naturally if orf starts spreading through the flock then you vaccinate.

It's unpleasant but not usually a death sentence - just an economic pain with higher workload and sorry sheep.

pgkevet · « **Reply #4 on:** April 25, 2014, 08:03:15 pm »

It just occurred to me to check the vaccine data.. and it;s unclear to me whether or how much the Orf vaccine virus is attenuated. It shuld be clear in the data sheet and isn't
http://www.noahcompendium.co.uk/MSD_Animal_Health/Scabivax_Forte/-58461.html

Effectively you have a superficial virus causeing lesions that the body isnt making good enough antibody response to..so you go and shove some more in to trigger that response.

This was also interesting reading (further down) as to the range of parapoxviruses and species affected.

http://www.virologyj.com/content/2/1/79

FiB · « **Reply #5 on:** April 25, 2014, 08:17:39 pm »

Ah thank you , that helps me a bit anyway. The filed I moved them to a couple of weeks ago is very thistley and has gorse too (really struggling to control the flat thistles). Have moved back to soft field today. So is it more in the land, or in the flock (who maybe havnt shown symptoms) In terms of next years plan?

pgkevet · « **Reply #6 on:** April 25, 2014, 08:24:22 pm »

Reiterate- don't take this as professional advice.
But it's in/on land and sheep and scratches, superficial traumas will innocuate and also reduce local resistance and allow it to show.
Probaby some parallel to take from 'cold sores' albeit thats a herpesvirus

Helen Wiltshire Horn · « **Reply #7 on:** April 25, 2014, 10:36:20 pm »

Just to add that my flock is in Surrey and I would be hard pressed to find a thistle in the pasture!

Helen Wiltshire Horn · « **Reply #8 on:** April 25, 2014, 10:53:09 pm »

My vet described it as being akin to chicken pox in human terms and as a nuisance factor in a small flock. I would therefore be very reluctant to innoculate especially as the lambs have been feeding fine and I have had no signs of mastitis. What initially confused me is that none of mine have had any blood on their muzzles as per all the photos I have seen and both lambs seem to be better today.

Brucklay · « **Reply #9 on:** April 25, 2014, 11:01:56 pm »

Once in a while I have had an orphan from my local farm with orf and it's 'no bonny' but it does clear up - as I understand thing the virus lives in the scabs so can lie dormant in the field/shed for some length of time. It's caught by small cuts on lambs- pin prickly coming into contact with the virus - I caught it last year with my dry cracked hands - not nice but not life threatening

SallyintNorth · « **Reply #10 on:** April 26, 2014, 03:06:22 am »

Yup, they don't die of orf. But it can become very unsightly and clearly very very sore. It's generally lambs which suffer the most - if it's on your land then your ewes will have some immunity to it.

Be aware however, that the vaccine is live, so once you use it, you do have orf on your land. So do not vaccinate unless you are sure you have orf.

And of course if you bring on recently vaccinated stock, then you bring the disease on as they will be shedding live virus.

We vaccinate if we have been getting significant levels of infection, so have vaccinated for the last couple of years as we had a lot of work washing faces and so on the year before that. Up until then we'd just had a few cases, none very severe, so hadn't been vaccinating.

Yes you can reduce the level of problem by keeping the lambs on ground where there aren't prickly things - thistles and gorse being two such - which will make lesions through which the virus can enter. And while you just have one family affected, I would be tempted to separate them if practical as they will be shedding live virus and increasing the risk of others getting it. Once more than a couple or three families are affected, it's a bit Canute

Lesions on the ewe's udder could have come from the lambs - if they're bugging her for milk, making small cuts and splits in the teats with their attentions, and have orf on their faces, they can infect her. If she's fit and well, it shouldn't be a big problem as she should have a level of immunity, but it can tip them into mastitis if they are under pressure already - for instance, short of milk, rearing triplets, etc.

Every year we discuss human infection with orf. A lot of us have had it, once, and it was unpleasant but really not terrible. However there are a few who've had it and it was horrendous. We've also run a poll to see if we thought that people who get cold sores maybe don't react so badly to orf, but that was inconclusive.