Prevention is always the best approach to downers. However, despite the best plans, the occasional down cow still occurs and the handling of the case determines the level of loss that will occur.

Down cows were in the national headlines after the BSE (mad cow) case a few years ago. Repeatedly the media defined a down cow as one that “was too sick to stand up”. While this definition fits some down cows, many of these cows have experienced injuries that prevent them from being able to get up.

Although there is a list of over a hundred causes for down cows, it is sometimes helpful to group the causes of downer cows into the following four categories:

• Cows with metabolic problems. Often these are deficiencies such as milk fever (low calcium in the blood), grass tetani (low magnesium) or winter tetani (low calcium and magnesium).
• Cows with injuries to their bones, joints or nerves. These range from severe fractures of bones or dislocation of joints to bad muscle bruising to nerve damage that results from a difficult calving.
• Cows that are weak from disease. Some of the diseases that cause cows to go down are sudden onset such as severe mastitis, uterine infection, poisonings or grain overload. Other diseases are chronic such as Johne’s disease, hardware, chronic pneumonia, etc. Nervous conditions such as circling disease or polio often cause cows to be down even though they have enough muscular strength to stand.
• Cows with end-stage conditions. Many of the cows that end up being downers at slaughter houses are crippled cows that didn’t withstand the truck ride. Starvation cows are often not noticed as being at the “end of their ropes” but, none the less, go down because they have exhausted their energy reserves.

Prevention of Downer Cows

Many cases of downer cows can be prevented. Once again, there are hundreds of preventive measures associated with the many causes of downer. However, the categories of causes above suggest major approaches to prevention.

• Cows with metabolic problems. Appropriate mineral provision for cows is crucial to the prevention of down cows. Magnesium supplementation around calving time, especially in the spring is important. Milk fever (low blood calcium) is not common in beef cows but is seen in high producers such as dairy crosses. Interestingly, too HIGH dietary calcium prior to calving increases the risk of milk fever.
• Cows with injuries to their bones, joints or nerves. Cattle can injure themselves in a wide range of ways and some injuries are simply classed as unpreventable. Good handling facilities that are kept in proper repair are important to the prevention of downer-causing injuries.
• Cows that are weak from disease. A good herd-health program is an investment in disease prevention for many reasons, only one of which is the prevention of downers. This must go hand-in-hand with careful observation of cattle and appropriate early treatment of disease.
• Cows with end-stage conditions. These downers may be the most preventable of all. The temptation to keep cows “just until she calves” or “until the calf is weaned” may end up being a poor decision if a downer results. In a year with very short feed supplies following a poor grazing year, downer cows with low energy will be a possibility. High risk cows are older cows that are heavily pregnant.

Dealing with Down Cows

Regardless of the primary cause, cattle are badly designed for long periods of lying down, especially on hard surfaces. Downer cow syndrome has been used to describe the conditions that develop in animals that are unable to stand. After as little as six hours with the inability to rise, they develop abnormalities of the muscles, nerves and joints. In one study of dairy cows only about 2% of cows treated for milk fever within six hours became long-term downers. However, with cows not treated for 7 to 12 hours over 25% became downers and nearly 50% of cows not treated until after 18 hours were unable to rise (Fenwick 1969).

When healthy cattle lie on their chest, most of the foreweight is on the brisket, while the majority of the hindweight rests on the leg under the body. Normally, cattle reposition themselves and alternate the leg on which weight rests (this often involves at least partial standing and lying back down on the opposite leg). When cattle are unable to do this, the down leg experiences extreme pressure which may put the nerves in the leg to sleep and influence blood circulation so that muscles are much weaker.

Getting the correct diagnosis of a down is crucial to the success of the treatment. Determining the cause of a downer is one of the most challenging diagnoses. Involving a veterinarian in the decision making allows a professional to help with both diagnosis and treatment. One tool to use is to offer the down cow palatable feed. Most cows down from starvation will eat ravenously while some cows with injuries will also eat. Most cows with metabolic problems and disease will not eat.

Since treatment for metabolic disease is relatively cheap so it can be used as a tool to determine the cause of the downer. If other disease causes are determined, they need to be treated immediately. In the mean time, attention must be given to the ongoing damage to nerves and muscles.

For many years marketing a down cow that was determined to be otherwise healthy (no signs of systemic disease) was an option. This ended by regulation soon after diagnosis of the first case of BSE (mad-cow disease). This leaves putting the cow to sleep, home slaughter and consumption and treatment as options.

Table 1 describes options for treatment commonly used in Virginia along with their requirements, advantages and disadvantages. Quickly finding down cows and proceeding with treatment will increase the odds of success whatever treatment is used.
Method	Requirements	Advantages	Disadvantages
Tail lift	Two to three operators; Non-slip surface; Lunging space	Straightforward, cheap	Only suitable for mildly affected cows
Nets, slings, cradles	Two to three operators; Must be fitted correctly; Lifting machinery	Relatively cheap; straightforward	Can be difficult to fit and harness.Cow must be accessible to lifting machinery
Hip lifters	One to two operators; Lifting machinery and hip lift device	Easier to fit than nets, slings, cradles	Cow must be accessible to lifting tools; potential injury and welfare concerns
Flotation tank	Two to three operators; Flotation tank and equipment systems	Probably the best; cow friendly	Quite expensive; quite time consuming

Down cows occur for many reasons. Prognosis is never excellent for down cows since this is a serious condition. Rapid diagnosis and early, appropriate treatment will minimize losses due to downers.

February 2008