It is usually the secondary damage, which happens as a result of them going down, that determines how they will go on rather than the primary reason. That said, it is important to try and get a correct diagnosis early on – so often we are called out to a milk fever which turns out to be toxic mastitis or some other condition. If a cow hasn’t responded to calcium treatment within 2-4 hours, it probably isn’t milk fever. If in doubt, call us out!
Much of the secondary damage can be prevented by quality nursing care so it is this rather than the initial treatment that has the biggest effect on survival. Secondary damage includes:
1. Compartment syndrome (also known as muscle damage) caused by pressure on the muscles of the hindlimb – we can assess the level of this damage by taking a blood sample. If the results come back over the threshold, the cow is unlikely to get up.
2. Nerve damage – both hindlimb and forelimb nerves can become damaged. Cows that get stuck on their side (lateral recumbency) particularly on a hard surface can damage the radial nerve (forelimb). Cows that ‘crawl’ or get stuck with their legs out behind (frog-leg position) can damage the femoral nerve (hindlimb).
3. Dislocated hip – cows that are down can be prone to dislocating their hip, this would obviously require euthanasia.
Nursing Care
Downer cows should be regularly assessed (every 4-6 hours) so they need to be moved to an appropriate shed where they will get looked at frequently. Regular turning/lifting should also be carried out at this time. Lying on a hard surface will rapidly lead to secondary damage – ideally, they should be on a deep straw bed or sand of approximately 30-40cm depth. To prevent ‘crawling’, cows should be kept in a reasonably confined space. Food and water should be in easy reach for the entire time a cow is down. NSAIDs (pain-relief) should be given for every case – products containing Ketoprofen have a very short meat withhold period when given intravenously so this should be the first choice.
If a cow fails to respond at all to treatment or appears to go downhill in spite of treatment, she should be euthanised or re-examined by a vet.
