Many suckler cows and calves have not been turned out post calving. On dairy farms, increased numbers in some areas has led to increasing disease pressure due to housing constraints. These have resulted in higher incidences of scour in calves, and increased losses.
Scour is generally caused by damage to the calf’s intestines, this in turn will reduce the calf’s absorptive capacity and result in the loss of fluids and electrolytes causing dehydration.
The least prevalent types of scour are ones caused by bacteria. So in most cases, antibiotics are of little benefit. The most common causes of calf scour are caused by parasites, namely Cryptosporidiosis and Coccidiosis. The next most common pathogens causing scour are Rotavirus and Coronavirus.
Symptoms and treatments
Typically a scouring calf will present with watery faeces. As the illness progresses and dehydration occurs, the calves eyes will become sunken and ears drooped. It will also appear lethargic and will have a decreased appetite.
Where calves/suckler cows and calves are housed and a calf shows signs of scour, then the calf should be isolated to avoid spreading the infection to the other calves.
Where sucklers are housed this may also mean having to isolate both cow and calf. An adequate level of bedding is essential to reduce the risk of spreading the disease. Where there is not additional housing to allow scouring calves and cows to be isolated, turning them out to grass may be more beneficial.
With the current poor ground conditions and wet weather, ensure that dry, sheltered paddocks or fields are targeted for turnout. Watch the calf and cow carefully, and if they are showing signs of discomfort due to weather such as having backs humped, house again during the night or periods of heavy rainfall. Scour samples should be taken to identify the pathogen and veterinary assistance should be sought in prescribing the correct treatment.
Feeding the scouring calf
Where calves are being reared artificially and a calf presents itself with scour, Animal Health Ireland advise farmers to continue to feed the calf through the scour as reducing the level of feeding only exacerbates the problem. Under normal feeding conditions, a calf will require at least 4L of milk per day to meet its maintenance requirements.
A sick calf will require even more feeding due to losses due to reduced absorption through damaged intestines and due to its increased energy demand as it tries to repair the damage to its intestines. AHI recommend that the scouring calf is fed 4L of milk/milk replacer per day and an additional 4L of electrolyte solution per day to replace lost fluids. This should be given in two 2L feeds in between each milk feed.
Farmers report varied success with the use of scour vaccines at farm level. In most cases, vaccinating the cow before calving will ensure that adequate levels of antibodies are available to pass to the calf.
However, the passage of these maternal antibodies depends on the level and timing of colostrum intake with the calf. The calf’s ability to absorb antibodies across the gut wall reduces gradually from six hours to 12 hours after birth. In order to maximise the transfer of antibodies, it is best practice to ensure the calf receives approximately 2-3L of colostrum within the first two hours of life followed by another feed at 6-12 hours. For farmers buying in calves, it is impossible to know what volume and quality of colostrum the calf has received.
Coccidiosis can occur both in suckler and dairy calves. It is a parasite that can be spread easily by calves coming in contact with and ingesting faeces on meal, feeders and straw. Calves can show clinical signs from three weeks of age onwards. It is most commonly identified by a bloody diarrhoea.
Early diagnosis and treatment is critical. Once coccidiosis is confirmed, all calves should be treated at the same time with a product such as vecoxan. Calves showing signs of the disease should be isolated immediately when scouring.
Cryptosporidiosis is the most common cause of calf scour. There are no vaccinations available to prevent the disease. Once an outbreak of cryptosporidium occurs, most farmers will treat all calves will halocur to prevent further occurrences of the disease. However, where there is a history of cryptosporidium, farmers will generally give a blanket treatment of halocur to calves to prevent against the disease.
Calf scours are generally passed on through the environment. It is essential that calving pens are cleaned after each calving and disinfected to reduce the level of disease in the pens. Calf creep areas and calf pens should be bedded daily to ensure calves have a clean dry bed and to ensure that contact with faeces is kept to a minimum.
A good rule of thumb when assessing whether or not enough straw is being used is to kneel on the bedding. If sufficient straw is being used, the bedding will be dry. If the weather improves, allowing cows and calves out to grass 4-5 days after calving can reduce the risk of scour significantly.
Source: Irish Farmers Journal