Flukicides and milking cows - The Accidental Smallholder

Posted: Sunday 3 January, 2016

by Rosemary Champion at 5:38pm in Cattle 1 comment Comments closed

I wrote this for the Shetland Cattle Breeders' Association newsletter but I thought I'd share it here too.

I thought it might be helpful to flag up the issue of flukicides and cows producing milk for human consumption. We started milking last summer (2015) – one cow was a fourth calver and the other a second. The issue of flukicide selection and milk production hadn’t crossed my radar before then. You may, at this point, be shaking your head and thinking “how could she not have thought of this before?” but although we’d had the idea to milk from Day 1, I’d dithered about it so long, i.e. four gestation periods, I suppose I’d kind of decided it was one of those good ideas that I’d never get round to J

I thought it would be useful to share our experience and mistakes – because even if you are not thinking about milking your cow NOW but might in the future OR if you are thinking about selling female stock to folk who are intending to milk themselves, then you need to have a think about this.

We have fluke on our land. Some of you may not, in which case, read no further. The livers from our tup lambs are usually condemned indicating that there has been fluke damage. However, the weights and condition indicate that our fluke management strategy is effective.

We house our cows and heifers around mid / end November, depending on the grass and ground conditions; the bull and steers rough it outside in some woodland. Because we don’t have very good (i.e. no) handing facilities for the boys, we’ve chosen to use a pour-on and, for convenience and to avoid buying two products and wasting more, we’ve used it on the females as well.

We have used an oral drench way back, but I ended up wearing most of it and in the early days of cattle keeping, I didn’t have the confidence to consider injectable wormer / flukicides (although I would now that we’re routinely vaccinating for clostridial disease).

The last two years, we’ve been using Closamectin, which is closantel (flukicide) and ivermectin (clear wormer, which also kills external parasites like lice and mange). I was conscious that, in using a combination product, we were probably treating the older cattle in particular for things that weren’t an issue but weighed against cost and convenience, Closamectin seemed likely to remain the product of choice. The likely alternative is Cydectin Triclamox Pour on which is triclabendazole (flukicide) and moxidectin (clear wormer that treats external parasites as well). Changing from Closamectin to Cydectin Triclamox would help to address any issues of resistance, even though ivermectin and moxidectin are similar BUT Cydectin Triclamox is not licensed for use on cattle of any age that is intended for milk production for humans.

Our routine has been to treat all the cattle, first, when we house the cows and for a second time about 8 weeks later – closantel is effective on fluke over 7 weeks old, so the second dose catches those too immature to be affected by the first dose. In fact, we were planning to change next winter to dosing the housed cattle just once, 8 weeks after housing by which would catch all the fluke (or 95% of them anyway). But this all became immaterial when the penny dropped about the milking cows.

My vet gave me his spreadsheet listing all available cattle flukicides, updated from the 2016 datasheets. I then went through that list and looked at those that have restrictions for use in cattle producing milk for human consumption.

• Cydectin Triclamox cannot be used on cattle of any age intended to produce milk for human consumption;
• some cannot be used in cows producing milk for human consumption even in the dry period (Closamectin; in in-calf heifers, it should only be used in the first half of pregnancy);
• some can be used in in-calf heifers and dry cows but there is usually a restriction on how late in pregnancy you can use it e.g. Ivomec Super, which is not to be used within 60 days of calving;
• there are some that can be given at certain times during the dry period and have a milk withdrawal period after calving e.g. Fasinex 240 that has a milk withdrawal period of 48 hours if given more than 48 days before calving and
• there are a few that can be given to cows in milk with a milk withdrawal period e.g. Albex 10%, which has a milk withdrawal period of 60 hours.

So the new plan is to continue to use Closamectin pour on for bulls, steers and heifer calves. We’ll take a faecal sample after treatment to check for efficacy. If it looks like we are developing a resistance problem, then we’ll change to Cydectin Triclamox, but treat the heifer calves with the cows and in-calf heifers.

The cows and in-calf heifers we’ll treat with Albex 10% (albendazole, white) at the higher fluke dose. This will also act as a wormer and we’ll faecal sample to monitor for any resistance. This is an oral drench so I’m going to buy a drenching hook for the drench gun to see if I can get more in the cow and less on me.

And we’ll just have to resign ourselves to drinking milk from cows that have, in the past, been treated with Closamectin – so if you see us start to glow in the dark, you’ll know what’s causing it.