[crobertson]

Just looking for help and advice regards flystrike and our lambs - I feel like I'm doing something wrong!

Our 8 lambs (first home bred lambs) were on poor grazing for a couple of weeks until I could move them, they had some hay in incase they were hungry but all were fine. I have moved them to their own field two weeks ago hoping they'll fatten up and start going but all lambs started to have messy bums. I have read this can be due to very wet grass (considering they were fine on poor grazing) or worms, they were last wormed 6 weeks ago but I have wormed them again to be sure.

 I rounded all of them up apart from one yesterday to trim off all of the dirty bits as they are due to be crovect'ed this week but I need to pick some up (last done 8 weeks ago). I noticed today one had a messy bum again so rounded them up only to find the poor thing has been struck by fly strike (can't believe it, I obviously didn't check it well enough yesterday). I also got the one who avoided capture yesterday again only to find the poor thing was  infested underneath the groin / testes, both were completed clipped and treated with the last bit of crovect we had left.

Anyway no I don't know what to do .... We are getting more crovect tomorrow and re-doing them all, should I use Clik is that better, should I move them on to poor grazing and supplement with hard feed and hay to dry them up a bit  ?? Our ram and wether in one field are absolutely fine as are our ewes in another field but they are on poorer grazing than the lambs.

[twizzel]

I've never had a problem with crovect as long as it is applied correctly and every 6 weeks. Any longer, or not put on properly and you'll risk strike. With the lamb that was struck underneath- just check his feet as quite often the maggots can go from feet onto the belly/groin or vice Versa. What were they wormed with? It could just be lush grass causing dirty bums, the grass with us hasn't stopped growing, a couple of my ewes were a bit green behind after a few days on lush grass although we have moved them off now and rotated with cattle.

[Possum]

You poor thing! It's a horrible thing to happen and can appear so quickly. It has happened to most of us so don't blame yourself for not spotting it.


I'm not sure that moving to poorer grazing will help the mucky bums and flystrike. I have had flystrike on completely clean lambs. Warm,humid weather is one of the main culprits for encouraging flies to lay their eggs.


Crovect is very good for treating flystrike but only prevents for 6 weeks. Clik does not treat already flystruck animals but prevents attacks for 16 weeks (if memory serves me correctly). However, it does have a long withdrawal period so you have to bear that in mind if your lambs are destined for the abbatoir at some point.

[crobertson]

Thanks for that, I thought it was 8 weeks but was thinking of doing them every 6 weeks over summer in future ! I will also check his hooves tomorrow although hes not lame in the slightest so would be surprised if feet were an issue, also they were wormed with Albex wormer.

Appreciate any advice.

[twizzel]

Crovect every 6 weeks and make sure your application is correct (as it only protects the fleece it is applied to). This year has been perfect conditions for strike- warm, wet weather. You could do a fec to see if you have white drench resistant worms or it could also be coccidiosis which has damaged the gut lining? May be worth getting the vet involved. Or it could just be getting accustomed to good grass. Our ewes were held tight for 2 weeks to dry off and then went out onto pretty lush grass, a couple of dirty bums but cleared up within a few days.

[Melmarsh]

Re strike , clikzin lasts 8 weeks and has a relatively short withdrawal compared to clik which should last 16 weeks and does have a longer withdrawal although both made by the same makers. It's worth mentioning that if the strike has broken the skin it's well worth getting a one off antibiotic injection and also a metacam injection for pain and inflammation. This is considered best practice Hope they recover well. I am also an advocate of FEC's before worming to prevent over use or use for no reason, certainly worth considering.

[shep53]

As others say CROVECT  only last 6wks  and only protects where it touches , so would not protect the lambs groin ( is the lamb a wether as if rubber ringed it can leave a wound )  DYSECT &   CLIK &  CLIKZIN spread all over the body and last longer .    Albex  not the best of wormers  and yes it takes awhile for  lambs to get used to young green wet grass . FEC is the only way do be sure

[Marches Farmer]

I use Clik as soon as I see more than six greenbottles in a day - generally some time in May.  I use a white drench at around 8 weeks and again four weeks later.  If you wait until the time lambs start scouring the damage from nematodirus and/or coccidiosis could be considerable and perhaps irretrievable.  Lambs are turned out onto a different field from turnout the previous year.  In humid weather maggots can hatch just hours after being laid.

[Red]

We had this problem in our first year and I vowed never to let it happen again ... We now dag all bumbs, and first sign of scouring send a sample to the vets. Any scouring I now wash the bumb in TCP wash, bit of nappy cream and extra spray with crovet and its worked - prevention is the way forward.

[Backinwellies]

One thing not mentioned here is that Crovect is less effective for prevention in wet weather ... don't know where you are in the country but here I doubt it would have been very effective even for 6 weeks.   

[YorkshireLass]

Just wanted to add some reassurance that you've spotted the problem, you're thinking along the right lines (looking for causes, thinking through possible solutions), everyone else has covered the practical things I'd say.

I'm also a big fan of doing FECs before any treatment, as drug resistance is a growing issue. My first suspicion would be the change in diet, but it also depends on body condition etc. Get the FEC anyway just to see where you stand.

[crobertson]

Thanks for all your help,
I checked the lambs hooves and they were fine, put some hay in with them to dry them up and none have scoured since that / worming.

We have been thinking preventative ourselves and thought about clipping the bums of all of the lambs routinely each summer to keep the fleece short and crovect every 6 weeks.

How often do people worm and what wormer do they use ? Is it just based on the results of a FEC or at set intervals ... I asked the advice of a local farmer for our lambs and they said they worm their lambs every 4 weeks. I thought that was way too much !

[Marches Farmer]

Shoulders, brisket, head, clees and (moving across from the clees) belly are possible flystrike sites as well as under the tail.  Crovecting every few weeks involves more handling and time, whereas Clik lasts 16 weeks and Clikzin 18.  Two doses of white drench for nematodirus, four weeks apart, still seems to do the trick around here.  We follow  SCOPS guidelines on alternating wormer groups and doing quarantine doses for the rest of the time.  FEC counts can be taken before eggs are in the faeces but damage is already being done to the gut wall.   Repeated dosing with the same wormer group and immediately moving the sheep to fresh pasture has led to almost complete wormer resistance in Groups 1, 2 and 3 wormers in NZ.

[twizzel]

Lambs had rycoben for nematodirus in May, ewes had it before they went out after lambing in March. Neither been wormed since, lambs' livers clear at slaughter, clean behind too. We cross graze with cattle though so rotation is an advantage we have and have relatively new grass leys too. I wormed 1 ewe at weaning as she was thin on advice of vet, she had Combinex and has gained condition since treatment. Ewes are fluked September (pre tupping) and December (when ram comes out). Religiously worming lambs every 4 weeks is the quickest way to resistance possible. I will also add that anytime our lambs or ewes have had strike it's been on the shoulder and back area, their backsides have been clean and the ewe in particular was crutched.

[pharnorth]

I had a very similar occurrence a few weeks ago. As you had, lamb was checked ok one day and my OH noted him less friendly the next day so we looked again. Pretty convinced the fly strike was no more than 24 hours as first maggots just appearing.
We were at end of the crovect 6 weeks too, but the Shearer was due.....  To cover the whole season I tend too do crovect long enough ahead not to affect shearing, then Clik for the main season and a last dose of crovect if like last year it is warm and muggy after the Clik cover has expired.