As we move into the height of summer, the conversation we’re having daily with sheep farmers across our region is the same: flystrike risk is climbing rapidly. With an upcoming heatwave forecast, conditions are becoming ideal for blowflies, and that means one thing – now is the time to be proactive, not reactive. From a farm vet’s perspective, products like Crovect play a crucial role in protecting sheep welfare during these high-risk periods.
Why Summer Equals High Flystrike Risk
Flystrike remains one of the most significant seasonal welfare challenges in UK sheep farming. It occurs when blowflies are attracted to sheep, lay eggs, and the resulting maggots begin feeding on the animal’s flesh. It’s distressing, painful, and can become fatal remarkably quickly if not treated.
What makes summer in the UK particularly dangerous is the combination of warmth and moisture. Blowflies become active at temperatures as low as 10°C, but their lifecycle accelerates significantly in warmer weather. During a heatwave, egg hatch rates increase, and maggots can develop in as little as 24 hours.
Add in common risk factors such as dirty back ends, footrot lesions, shearing wounds, or even minor skin damage, and you’ve got the perfect scenario for an outbreak.
The Impact of Heatwaves
The predicted heatwave we’re about to experience will put even well-managed flocks at risk. High temperatures not only speed up the blowfly lifecycle but also increase sheep vulnerability:
- Sheep spend more time lying down, increasing contamination risk
- Dagging can become more challenging if faecal consistency is loose
- Stress from heat can reduce immune resilience
- Fly activity peaks earlier in the day and lasts longer
In short, what might normally be a manageable level of fly pressure can quickly spiral into a serious welfare issue.
Where Crovect Fits In
Crovect is a synthetic pyrethroid pour-on specifically designed for the treatment and prevention of blowfly strike in sheep. From a veterinary standpoint, its value lies in two key areas: rapid knockdown of existing strike and preventative protection.
- Treatment of Active Flystrike
Crovect is highly effective at killing maggots already present on the sheep. When applied correctly to affected areas:
- It provides quick maggot kill
- Helps prevent further tissue damage
- Reduces the risk of re-strike
However, it’s important to stress: treatment alone is not enough. Affected sheep must also be clipped, cleaned, and monitored closely.
- Preventative Protection
One of the biggest advantages of Crovect is its use as a preventative. Applied along the backline, it offers up to 8 weeks of protection against blowfly strike under typical conditions.
This is particularly valuable during a heatwave when:
- You may not be able to gather sheep as frequently
- Fly pressure is consistently high
- Risk periods are prolonged
Using Crovect strategically before peak fly activity can significantly reduce the incidence of strike across your flock.
Best Practice for Summer Application
From a practical on-farm perspective, timing and technique are everything.
- Apply ahead of risk: Don’t wait until you see strike, by then, you’re already behind.
- Target vulnerable groups: Lambs, ewes with dags, and recently shorn animals should be prioritised.
- Ensure correct dosing: Underdosing not only reduces efficacy but can contribute to resistance issues.
- Combine with management: Dagging, shearing, worm control, and foot health all reduce flystrike risk.
It’s also worth remembering that no single product is a silver bullet. Fly control should always be part of a broader flock health plan.
Welfare, Productivity, and Peace of Mind
Beyond the obvious welfare implications, flystrike has a direct impact on productivity. A struck sheep will rapidly lose condition, and in lambs particularly, growth rates can nose-dive. In severe cases, losses are inevitable.
From a farmer’s point of view, there’s also the hidden cost: time and money spent catching and treating sheep in the middle of a busy season. Prevention is always more efficient than cure.
Final Thoughts From Us
If there’s one message we’d like to emphasise heading into this spell of hot weather, it’s this: don’t underestimate how quickly flystrike can escalate.
We often see a surge in cases following just a couple of days of warm, humid conditions. By the time the first sheep is visibly struck, others are often already affected.
Crovect remains a valuable and reliable tool in our summer parasite control arsenal. When used correctly and proactively, it can make a tangible difference to both sheep welfare and farm efficiency.
With a heatwave on the horizon, now is the time to act. Give us a call on 01746 713911 to place your order.
