Thursday, April 15, 2010

Trouble In Paradise

I'm going to start this post by quoting from Eddie Stratons sheep book. Sorry I don't know the title of the book. Becky sent me this quote in an email two years ago.
"Daft Lamb Disease:
Like swayback, daft lamb disease is a condition of new born lambs and is the only disease know which is likely to be mistaken for swayback: in fact the two conditions are sometimes indistinguishable.
Fortunately, however, daft lamb disease is uncommon and is seldom, if ever, a major problem. It is chiefly in the Border Leicester breed and its crosses, e.g. the Scottish halfbred and the Greyface.
Cause
Daft lamb disease is not due to a mineral deficiency but is genetic in origin. Part of the lamb's brain the cerebellum is congenitally atrophied (imperfectly developed).
Symptoms
Most cases have a characteristic jerking backwards of the head. They carry the head high and have the mouth pointing backwards or towards the side. In the more severe cases the lambs are blind and walk in circles. Despite this the appetite remains good.
Treatment
There is none, though mild cases can be hand reared and given a chance. Most cases are destroyed by shepherds or die of exposure or starvation. Those that can walk may improve gradually, and some may become apparently normal except when excited.
Prevention
Cull the mothers and change the tub (ram). One obvious preventative measure is to avoid buying rams from flocks where the condition is know to exist." end quote.

Since 2007 I have witnessed lambs born in my flock with these symptoms. Now in 2010 I can be sure that it only happens to the sheep I have identified as "carriers" bred to other "carriers".  I get totally healthy lambs when a carrier is bred to a non-carrier or of course two sheep who do not have this recessive gene. I had all healthy lambs born last year. That ram, Cider, I believe was not a carrier since all his lambs were healthy but was culled because of horns that turned into his head.

Kess's ewe lamb born the morning of April 12, 2010 and below is Sisken and her two lambs born the same day from the same ram. Siskens two lambs are both doing great. Sisken has always had healthy lambs and I do not consider her a carrier because of this. She has been bred, in my experience, to both carrier and non carrier rams.
Kess was considered by me to be suspect since her full sister Bella had the two blind lambs '08. Kess had a normal ewe lamb last year and this ewe lamb of hers is blind. Oma bred to the same ram was to me a carrier, she had twins in '08, one blind and died the other healthy. She had two healthy lambs last year. This year when Oma was bred  to the same ram as Kess, she had twins again one was blind and died, her ram lamb is doing well.

I culled my rams and most of my ewes who were carriers but kept a few ewes that are carriers to test any new rams I would get in the future. So each of my rams were given two carrier or suspect ewes as a test. Bella bred to a different ram than Kess or Oma has two healthy ram lambs this year. Plus she had two healthy lambs in '09. This after her two blind lambs in '08.
So far this year one ram has had four ewes lamb. Two carriers and two non carriers, like I say this is my opinion, both carriers had blind lambs and both non-carriers have healthy lambs. Two more ewes bred to this ram have not lambed yet. One Yeesha I  believe is a non-carrier, from a ewe and ram  who's genetics do not link to daft lamb in my flock and Hazel, suspect because her sire was one of the original rams to plant this seed of daft lamb in my flock. Hazel is a two year old and this is her first lambing. She will have a one in four chance of carrying the gene.
My other ram has had two ewes lamb one Bella a carrier and Hattie who could carry the gene both have healthy twin lambs.
This is an ongoing study and bless you Laura Cunningham for getting in touch with Phillip Sponenberg DVM PhD who has encouraged me to compile all my records of affected lambs. God bless blogs who got me, a fairly lame record keeper to document my lambings since 2008.
I was ready to just cull all animals who I have, that have had trouble with this and hide these lambs from everyone. Instead I find this very distressing since it has been talked about in the Shetland sheep for more years than I have been breeding Shetlands and I find more "hide it under the rug" people than ones who wish we had a way of testing our sheep to rid the Shetlands of this problem. My Opinion
P.S. these sheep have been followed by vets and had necropsies and blood tests done from the West coast to the East coast where all the common viruses, bacterias etc have been ruled out. And if it were one of these why does this happen to only Shetlands and only some family lines of Shetlands. My sheep are proof of that.

12 comments:

Michelle said...

Mim, I'm so sorry to hear that you've had affected lambs again this year! I am pretty new to Shetlands, but have only heard of this through you. Thank-you so much for your willingness to talk about it, and have your sheep studied.

Laura said...

Shetlands aren't the only ones that this happens to, but it seems that your flock is unfortunately blessed with the opportunity to observe and learn from this.

I'm speculating, as you are, that this is a lethal recessive. Your "carrier" sheep are Dd (daft Dominant/daft recessive). This is what makes it so hard to tell, since they don't express the symptoms, until bred to another carrier, and 25% of the time you'll get a daft lamb (remember Mendel's peas). It's very nearly impossible to completely remove a lethal recessive - they are really, really good at hiding.

I wish I was a biologist (in a lab) - this is exactly the kind of thing that really blows my skirt up! If someone were to sequence the shetland genome, it might be possible to identify the gene/genes responsible, and test for them, like we test for scrapie and foot rot.

I am so sorry that you're continuing to have difficulties. Clinically, it's very interesting - but it's heart-wrenching to have to go through this again, and again...

Hang in there. Maybe we can find a grant to get this looked at...

~~Sittin.n.Spinnin said...

Hey Mim, the book is called 'Sheep Ailments', Dr. Stratton is an Englishman, and though it deals with mostly European breeds, the book is very informative and I've used it many times in looking for and diagnosing problems.

Leigh said...

A sad but brave post, Mim. We would all love for life and livestock breeding to be problem free and perfect, but obviously it isn't. Testing and good records would seem first step to this problem. Hopefully you are playing an important part in that, from your corner of the world.

Sharon said...

I love your beautiful flock and enjoy hearing them every time I get out of the car. It's so sad that you have to continue to deal with this situation. I hope this is the last year.

Jenny Holden said...

What a hard thing to have to deal with, but you approach it in such a brave and useful way. I wish you much success in researching this further. I have never heard of it!

Pam in Wisconsin said...

Wow this was very informative---thankyou. I recently sarted a shetland flock crossing with a border leichester ram. Thankfully have not seen this. It's amazing what can happen even when you care, feed and love them well. So sorry for your troubles.

Kathy said...

Mim, I was heartbroken to hear you're having this problem once more. Like Michelle said, I have not come across this at all in Shetlands except from you. Your documentation of this will be critical for discovering where this is coming from and you do us all a great service by letting us know about it.
I, too, thank you for taking the time to inform us of this terrible crisis you're dealing with. Please know we're all here for you if only to have others to bounce ideas off of.

Gail V said...

Bravo, bravo,
I just want to echo others' sentiments regarding your brave forthrightness, and my sympathy at the problem of having lovely little sheep that are so afflicted. It must be heartbreaking. You'll work it out, in time. Best wishes.

Marion said...

Good for you! I too have been dealing with a genetic problem in my flock of Shetlands, though this one seems to be a sex-linked gene. it makes little difference which ram I use on the girls, the ones in this line have perfectly healthy ewe lambs, but about 50% of the boys are what we call "goofy". they just act stupid. they have a very strange cry, very weak and feminine, loose mom easily in a crowd. they nurse just fine, and seem to do well. when they are about a month old, they show signs of pnemonia, which clear up. then as they get older they gradually get worse, and one day I find them dead. I've never had one live over a year. some of the ewes in this line don't have "goofy" boys, and the boys that don't get that gene seem to be fine, as are thier lambs. if you want to, I would welcome any advice :-) I haven't sold ant of the girls except as pets, but I need to get rid of them soon as they are multiplying .....

Kathy said...

Mim,
The more I think of this the more it sounds like PEM (polio) to me. While, if it is, you can treat for it, it requires uber-diligence and time as well as massive amounts of vitamins and support for quite some time and not everyone is willing to spend that much time and energy.
As I mentioned, I have not run into anyone who has had this in their Shetland flocks - I've seen DLD in other breeds, years ago, requiring the owner to heavily cull all animals - ewes especially.
I would hope that, by now, testing/tests/necropsy would be able to confirm it, or rule it out.
Have the rams you've used sired lambs on other farms without incident?
The problem is that from your description this could be a number of things - even toxicological (but then as I did toxicology work for Richardson, Merrill-Vicks before I went into investigations, I tend to look at that aspect as well).
I do hope a solid answer can be found for your issues. At least you've determined who has problems with it so you can determine who to cull.

Kathy said...

I meant to ask if any necropsy revealed atrophy in the brain??? That would confirm DLD.