[tommytink]

I was considering using Crovect on some lambs. I believe Clik is better but I have some Crovect going out of date and want to make use of it.
I’ve checked the NOAH page and it says a 20ml dose but the application diagram shows it going straight down the back to the tip of the tail in two sweeps. The 40ml dose shows more like what I did with the Clik last year: sweeps down the back and then up and over the rump. Can anyone advise how they’ve applied it? I’d have thought it would have been the same no matter what the dose is.
I’m getting them in today to go to a neighbours’ field for a couple of weeks. Was going to do it before they go but rain is forecast and I’m not sure they’re all sufficiently over 12.5kg. The fact there’s a minimum weight makes me want to wait till they’re definitely a bit bigger as read it can cause neurological problems? They’re all getting a back end trim today at least, and I’ve rarely seen a messy bum in the breed since I’ve had them, so bottoms are generally clean. Plus the flies I’ve seen around are more plain black ones, not too many bottles.
Thank you!

[SallyintNorth]

Crovect absolutely can cause neurological problems if used incorrectly.  I have had this when we accidentally overdosed a batch we were treating preventatively for headflies.  Two of the batch lost the use of their legs and took many months to fully recover.

I've never used them but as I understand it, Clik and Clikzin are systemic, get into the tissues, and are more environmentally harmful - but if you think the lambs could be at risk and you can't keep a close enough eye on them then it could be the better option. 

As to the dosing diagrams for Crovect.  Crovect protects only the areas on which it lands on the wool.  So the patterns you spray depend on the overall dose (20ml cannot cover as much wool as 40ml) and what your experience tells you are the most likely sites for strike in your locale with your sheep.  Set your gun to 5ml if you can, or 10ml, so you can distribute the total dose between a few sprays -  but with young lambs you will only be able to do 2 sprays if the smallest dose you can set your gun to is 10ml.  You don't have several years' experience of your sheep on your ground yet, so if it were me I would spray 1) arc around the tail 2) across the shoulders, then for bigger lambs, 3) down the back, and anything over 25kgs add 4) top of head to shoulders, or replace 3 and 4 with a stripe along each flank. 

[twizzel]

Crovect has different ways of applying for different things- ticks, established strike and prevention of strike. Should say on the label how to apply for each one- you need prevention- I think if I remember it’s 4 stripes. So divide the amount for the weight between 4 and that should work. Make sure you wear gloves and long sleeves/trousers as it’s nasty stuff. It’ll only last 6 weeks so need to keep an eye out end of July and reapply.

[landroverroy]

Crovect can be diluted 10x with oil and it is still effective. It will prevent flystrike and kill established strike.


So how did I discover this? Well permethrin in its various forms is a well established as an insecticide, not just for animal use. I noticed that to kill insects in totally different environments, it was used at a much greater dilution. When Crovect or SpotOn  got on my own skin I realised how irritating it was and so was loath to use the strong product on the poor sheep that couldn't wash it off. I was particularly loathe to put it on the raw flesh that had been attacked by maggots, so I diluted it 10x with water and found that the maggots still quickly died.


However, when diluted with water for prevention purposes, the solution didn't seem to stay on the fleece, because of the grease. So I diluted it with oil instead and found it great. By diluting it 10x you can obviously cover 10x the area with the same recommended dosage, and as it only prevents flystrike where it has been applied, then you can actually protect most of the animal. I actually dilute with red diesel (cue the cries of disapproval from those who have never used it!) as the smell of diesel also repels the flies. But you can use cooking oil or whatever you want. But the thing is - it works. 

[tommytink]

Thanks all. I’ve only got the stuff due to the hornless ram, although I also had to use it on his son for the same reason so was glad to have it. Interesting how it could be diluted and it still be just as effective.

I much prefer Clik for prevention, as it makes better sense in that it covers the whole area, not just where you put it. Got this Crovect going off in October though, plus with a shorter withdrawal I thought it’d be good for the Badger lambs. I’m not sure why the diagrams are different for a 20 and 40ml dose. Would’ve thought the pattern would be the same (shoulders/back/bottom) whatever the dose. My gun does go down to 5 I think so I’m reality I can put it where I want as long as I don’t exceed the maximum.

Ideally I wouldn’t use anything and try and ensure fleece is clean, but the thought of getting strike worries me so. I find the Badgers rarely have jippy tummies, but I wouldn’t be able to check them as easily as the Radnors (who for some reason are messier).

As it turned out they felt all different weights. The OH tells me to think of carrying a 25kg of ewe nuts to compare but I’m useless! One little ram I could carry with one arm so don’t think he weighed much more than my little sausage dog!! Weigh scales are number one on my wish list!!

[twizzel]

You’re right to still protect for flystrike- I had 2 shearlings struck before shearing this May, both were struck on clean fleece between their shoulders. Just yesterday I was out checking the sheep and a few clean lambs had bluebottle flies around them (they’ve all had Clik so it’s ok). With the warm damp climate unless you’re right up on a mountain, putting pour on on sheep is a job most sheep farmers do throughout the summer, even after ewes are shorn.