As a new graduate, the call to a down cow can be frustrating. Although the initial cause of recumbency has a vast differentials list – too big a topic to be discussed in this article alone – they are only truly referred to as a “downer cow” after 24 hours or more of recumbency (Figure 1).
This article will focus on the care of downer cows rather than the initial causes of recumbency, as compliance with downer cow care is often a challenge and prognosis of the animals is often poor.
So, how do we improve downer cow diagnosis, prognosis and satisfaction?
Increasing efficiency before arrival
Triaging the patient on the way to the call will give you some clues as to what differentials are more likely and what you might need from your vehicle on arrival.
Establishing if there is one down animal or multiple will further help refine the likely differential list. For instance, if you are presented with a group of recumbent animals, nutritional causes such as ruminal acidosis or toxin ingestion (eg botulinum toxin, nitrate poisoning or hydrocyanic acid poisoning) will move higher up your differentials list.
Establishing if there is one down animal or multiple will further help refine the likely differential list
The stage of lactation further narrows your differentials list prior to arrival, but it is important to keep an open mind.
Making the client aware you might want to lift the animal on arrival can help with speed of diagnosis and treatment to an extent as well. Clients can get hip lifters, ropes and tractors at the ready to avoid a hefty vet bill while waiting for equipment.
The cause of the downer cow
Differential diagnosis for initial recumbency in cattle is vast and, again, outside the remit of this article. However, Poulton et al. (2016) published the findings of their Australian study, which found that the primary causes of recumbency in the cattle studied were calving paralysis (45 percent), back injury (19 percent), milk fever (17 percent), protein-energy deficiency (14 percent) and “other” causes (5 percent).
It is common knowledge that fixing the primary problem may not result in the animal standing; subsequently they become a “downer cow” due to the developing secondary muscle and nerve damage as a result of ischaemia, also known as compartment syndrome (Figure 2).
Additional problems that can be seen are dehydration from poor downer cow care and gastrointestinal upset from ruminal atony.
Maximising downer cow care
Huxley et al. (2010) discuss the importance of feed, water and nursing care for downer cows. It can be useful to break down the required care for downer cows into the following three categories: turning, lifting and comfort, or “TLC”.
Turning is required every few hours, and lifting in a safe manner should be done multiple times a day. Comfort can be further broken down into food, water, bedding, udder (or milking) and pain relief. If the client is unable to provide turning and lifting, then the prognosis for that animal is poor. Euthanasia, although seen by some as accepting defeat, will ensure animals do not suffer due to inadequate care.
Turning is required every few hours, and lifting in a safe manner should be done multiple times a day. Comfort can be further broken down into food, water, bedding, udder (or milking) and pain relief
Poulton et al. (2016) mirror these key elements for downer cow care and provide an overview of the key components of the optimum standard of nursing care when dealing with downer cows, stressing the importance of the safe movement of down animals between locations, for example using a front-end loading bucket.
In the study by Poulton (2020), 79 percent of downer cows suffered “clinically important” secondary damage from recumbency, and unsatisfactory levels of nursing care resulted in minimal chances of recovery after five days of recumbency. This study followed animals for a period of 28 days and the recovery rate was 32 percent overall.
Prognosis – what are the chances they’ll get up again?
Peripheral nerve damage can be seen with recovered downer cows, with the peroneal nerve being the most commonly damaged. So, additional tests on reflexes are useful to assess peripheral nerve function. The commonly tested pedal reflex is used to assess if the animal can withdraw the limb when painful stimulus is applied to the foot (Andrews, 1990).
Pre-treatment bloods for metabolic conditions such as hypocalcaemia and hypomagnesaemia are useful tools for confirming diagnosis if the animal does not respond to treatment as expected (Figure 3).
Downer cow profiles, including urea and creatine phosphokinase (CK), are readily available at external laboratories for less than £30, which can aid in formulating a treatment plan and indicate the animal’s prognosis. Clark et al. (1987) provide reference ranges for CK to assess the prognosis of the animal (Table 1). If elevated above these thresholds, a 5 percent chance of recovery is to be expected.
|Day of recumbency||CK value (U/l) (normal reference range 0 to 370U/l)||No. of times CK reference range upper limit||AST value (U/l) (normal reference range 25 to 120U/l)||No. of times AST reference range upper limit|
|Day 0.5||Greater than 12,200||33||Greater than 890||7.5|
|Day 1||Greater than 18,600||50||Greater than 890||7.5|
|Day 2||Greater than 16,300||44||Greater than 890||7.5|
|Day 3||Greater than 14,000||38||Greater than 890||7.5|
|Day 7||Greater than 3,900||10||Greater than 890||7.5|
TABLE (1) The values of creatine phosphokinase (CK) and aspartate amino transferase (AST) which indicate a lower than 5 percent chance of recovery from recumbency based on published findings of Clark et al. (1987). CK has a short half-life (two to four hours), so needs daily values unlike AST. Most laboratories will provide guidance on interpreting lab results
The herd health approach
The Red Tractor Assurance scheme is updating its standards in November 2021. One of these updates is an annual veterinary herd health plan that is specific, is tailored to the farm’s needs and creates plans to improve welfare for the coming year. The Red Tractor health plan template also discusses the need to have a hobbles/shackles policy for each individual animal, noting date and reason for application as well as the decision plan for each individual animal.
It is important to establish if the downer cow is an individual isolated event, multiple animals at one time or multiple animals presenting with the same condition over time. This can then be reflected upon in herd health plans and used to make plans to reduce incidences of downer cows for each identified reason, eg regrooving on slippery concrete yards and opening up of passageways to reduce bullying and slips.