Sheep poisoned by bracken?

[Andyt880]

I’ve lost 3 ewes in the last 10 days. All with identical symptoms. They go blind all of a sudden and walk into the hedges and get stuck. Few hours later go off the legs and go into fits and constantly shacking, they just gradually deteriorate after this.
The first one I just put it down to a meningitis type infection and put the ewe out of her misery. The second was dead in the hedge when I found her but had been foaming around the mouth the same as the first.
I got the third one in the hedge fairly quickly and got it to the vet. He say it’s poisoning from something they are eating and the toxins are going straight to the brain.
Treated the last one with antibiotics, steroids and B vitamins but she was dead this morning.
I have came to the conclusion it was happening after I had them in the handling pen which is built along the side of one field. When I looked I can see where they have eaten bracken down to stumps that was growing along the outside edge of the pen. It’s the only thing that I can find that they have eaten which might be the cause. Any one ever seen anything like this before?
Ewe one died 10 days ago after being in the pen 2 or 3 days previously. They were last in the pen on Saturday past and ewe 2 died on Sunday and ewe 3 was poorly by lunch time Monday. No sign of any thing poorly since so I’m almost sure it’s coming from the handling area.
All 3 ewes have been found blind and stuck head first into the hedge

 

[Andyt880]

Just to add we generally don’t have any bracken growing in the fields, just the odd bit in the hedge bottoms and the hedges are all electric fenced off so they would have very little exposure to it. Grass is getting low but they are far from starving yet

 

[toquark]

I thought bracken poisoning only resulted after long term exposure? Or the effects don't become apparent for a long time?

 

[Andyt880]

I thought bracken poisoning only resulted after long term exposure? Or the effects don't become apparent for a long time?

I don’t know much about bracken to be honest. I can’t find anything else that they could have eaten

 

[Sharpy]

Might be an old wives tale but I was told years ago that you only got bracken poisoning where stock did not have an ample water supply.

 

[Andyt880]

Might be an old wives tale but I was told years ago that you only got bracken poisoning where stock did not have an ample water supply.

Well my sheep are drinking water out of an ibc and should have water all the time but sometimes it could run out in the evening and not be filled until the next day. Things are very dry here atm, we’ve had no rain for a good while. It’s possible that they ran out of water just at the critical point where they needed it to flush their system. Or would it possible that the ewe ate it and just didn’t go to the water?

 

[Cvx1170]

sounds more like low mag or calcium

 

[Andyt880]

sounds more like low mag or calcium

Never seen mag or calcium deficiency in ewes that are ready to have their lambs weaned and in great condition. Vet was certain it was pinioning

 

[Sharpy]

Well my sheep are drinking water out of an ibc and should have water all the time but sometimes it could run out in the evening and not be filled until the next day. Things are very dry here atm, we’ve had no rain for a good while. It’s possible that they ran out of water just at the critical point where they needed it to flush their system. Or would it possible that the ewe ate it and just didn’t go to the water?

Possibly. The chap who told me had a hill that couldn't be grazed due to bracken poisoning, he said he discovered that any cases he could find were on dry hills, those with a burn etc running through didn't seem to give bother. He installed a trough and never had any bother.

 

[CopperBeech]

Not Ccn is it ?

 

[Nithsdale]

Bracken Fern Poisoning in Animals - Toxicology - MSD Veterinary Manual

Learn about the veterinary topic of Bracken Fern Poisoning in Animals. Find specific details on this topic and related topics from the MSD Vet Manual.

www.msdvetmanual.com

 

[Andyt880]

Not Ccn is it ?

I did ask the vet about CCN but he said it is more a thing in growing sheep. His opinion was it could occur in adult sheep but the chances of 3 ewes so close together and no lambs showing signs of it were slim. I don’t know a lot about CCN really

 

[Andyt880]

Not Ccn is it ?

Is it possible that the toxins in the bracken could cause CCN?

 

[BPip]

In horses bracken/ferns contains thiaminase and causes acute B1 deficiency, blocking thiamin so neurological symptoms/tremors etc - its fairly rapid - so sounds like your sheep experienced similar..? They’d have to eat a fair amount as a horse, but most dont as its unpalatable. A sheep being smaller body weight probably affected by a few stalks.

Thiamin/vit B1 is handy to have in stores if you do have bracken in hedgerows, which is where most of it likes to grow.
Its a last ditch attempt to get some B1 into them to overcome the bracken blocking body stores of the vitamin.

 

[Andyt880]

In horses bracken/ferns contains thiaminase and causes acute B1 deficiency, blocking thiamin so neurological symptoms/tremors etc - its fairly rapid - so sounds like your sheep experienced similar..? They’d have to eat a fair amount as a horse, but most dont as its unpalatable. A sheep being smaller body weight probably affected by a few stalks.

Thiamin/vit B1 is handy to have in stores if you do have bracken in hedgerows, which is where most of it likes to grow.
Its a last ditch attempt to get some B1 into them to overcome the bracken blocking body stores of the vitamin.

Would it be possible maybe that the bracken contains more thiaminase at certain growth stages and they just happened to have eaten it at the worst time?

 

[Agrivator]

Yew seems to be the only plants to which sheep often have access and which causes sudden death - even in very small quantities.

Bracken poisoning normally occurs a long time after ingestion., and even then the symptoms of bright blindness can last a long time. And sheep will often nibble bits of bracken in late summer when it starts to senesce with little obvious hurt.

Are you sure that the fern you refer to is actually bracken, and not some other more lethal species.

 

[Andyt880]

Yew seems to be the only plants to which sheep often have access and which causes sudden death - even in very small quantities.

Bracken poisoning normally occurs a long time after ingestion., and even then the symptoms of bright blindness can last a long time. And sheep will often nibble bits of bracken in late summer when it starts to senesce with little obvious hurt.

Are you sure that the fern you refer to is actually bracken, and not some other more lethal species.

Good point, it could be a variation of it that is more lethal, I’m not sure. It’s growing wild along the hedge so I just assume it’s normal bracken.
I am assuming it’s the bracken that is causing the issue as it’s the only thing that I can see they have eaten out of the ordinary, no definite answer that it is the problem

 

[coniser]

When l have had trouble with bracken there is usually blood in the froth as the bracken cuts the insides of the stomach

 

[Andyt880]

When l have had trouble with bracken there is usually blood in the froth as the bracken cuts the insides of the stomach

I noticed a lot of blood coming from the mouth of ewe number 2 after she died.

 

[Nithsdale]

When l have had trouble with bracken there is usually blood in the froth as the bracken cuts the insides of the stomach

Bracken doesn't cut the inside of the stomach. It causes hemorrhaging throughout the body