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Calf Scours

Calf scours or diarrhoea can become a big problem in some herds. However, prompt treatment, hygiene and isolation measures can help to keep this problem minimised in your herd. Scroll to the bottom for treatment protocols for calves.

Causes of Calf Scours:

1. E.Coli

E.coli is a bacterial diarrhoea occurring in calves around 1-4 days old. It produces a yellowy-white, watery, smelly scour. Calves get infected orally due to contaminated faeces of other animals. Calves can die very quickly of E.coli if not treated. Antibiotics such as Excenel or Vetrimoxin are required to control infection.

2. Salmonella typhimurium

Salmonella is most commonly seen in calves over 7 days old. Many calves carry Salmonella bacteria in their bowel, but inadequate immunity causes overgrowth of the bacteria and then infection. Salmonella is zoonotic and so can cause infection in humans so hygiene, isolation and care is needed if this bacteria is diagnosed as the cause of calf scours.

Salmonella diarrhoea can range from yellow colour to bloody depending on severity of disease, and is often very smelly.  The bacteria can cause death in calves within several days if not treated with appropriate antibiotics eg. Marbocyl, Noradine, or Engemycin.

For colostral protection of calves, ideally cows should receive their annual Salvexin vaccination around 4 weeks prior to calving.

3. Coronavirus

This type of viral scours occurs in calves aged 1-3 weeks, and the diarrhoea may last for up to 10 days. Diarrhoea is profuse and watery at first, and then can become mucous and bloody.  Coronavirus can be seen with other scour diseases such as Rotavirus, E.coli and Cryptosporidium.

4. Rotavirus

Rotavirus scours mostly occurs in calves less than 10 days old. Infection is due to contact with other affected cows and calves, and may be seen concurrently with Cryptosporidiosis. The diarrhoea from Rotavirus is yellowish and watery. Many calves  from multiple pens may be affected in the shed and mortality can be variable.

Prevention includes vaccinating pregnant cows with the Rotavec vaccine, 1-3months prior to calving. This allows passive immunity of the vaccine to the calf via the colostrum. Rotavec will only work if the calves are receiving adequate, high quality colostrum.

Another method of prevention and treatment is the use of Rotagen, a colostrum replacement with freeze dried antibodies in it.

5. Cryptosporidium parvum

Crypto is a protozoal parasite and occurs in calves from 4 days to 4 weeks old, with the diarrhoea lasting up to 17 days. Infection in the intestines can occur by ingestion or inhalation of the virus. This disease is zoonotic so is contagious to humans too, therefore hygiene is important. Deaths from Crypto alone are uncommon but the whole shed may be affected in some cases.

Crypto is a very painful disease therefore anti-inflammatories such as Tolfedine or Metacam are indicated (but should only be given to well hydrated calves).

6. Coccidia

Coccidiosis is a parasitic disease seen in calves 1-6 months old. Stress predisposes to disease outbreak. Coccidiosis can occur when calves are stopped feeding meals with coccidostats, or when they are moved onto pasture with a high build-up of infection.

The diarrhoea may be bloody, and if left for a couple of hours there may be a metallic sheen on the diarrhoea puddles. Straining is often seen. Affected calves may appear ill-thrifty for weeks due to the intestinal damage caused by the parasite.  The overall rate of affected calves with clinical disease is low.

Prevention is by feeding coccidiostats in calf meal such as Monensin, although calves need to be eating enough meal to be getting protective levels of the coccidiostat. Active immunity is usually established by 6 months age.

Calves with this disease require anticoccidial drugs such as Baycox, and antibiotics such as Noradine.

7. Nutritional

Nutritional scours are seen when calves change from colostrum to milk replacer, or when feed regime changes from twice daily to once daily. Calves with nutritional scours are happy and healthy and are easily differentiated from the diseases causing scouring.

The consequences of scours is loss of fluid into the intestine, therefore the most important treatment for the calves is FLUIDS.

Treatment of Scours

Treatment is based on correcting fluid loss, metabolic acidosis, electrolyte imbalance and low blood sugar levels.

Intravenous fluids may be required for calves that are collapsed and can’t suckle. Only once the suckle reflex is present are calves able to be tube fed (or bottle fed).

Milk should never be stomach-tubed to a non-suckling calf, as the milk stays in the rumen and ferments, causing inflammation. Oral electrolytes however, can be stomach tubed in a calf that is not suckling. It is important to note that electrolytes do not give the calf energy or stop weight loss, they only correct the electrolyte imbalance caused by the diarrhoea. As soon as the calf is suckling again – give milk as this contains energy and nutrients.

Calves require a minimum of 2 litres 3 x daily - A 40kg dehydrated calf with scours needs around 8 litres to correct fluid deficit and maintenance.

A good protocol for a suckling calf is:

DAY 1: 2L electrolytes 3 x daily

DAY 2: 2L electrolytes, 2L milk, 2L electrolytes

DAY 3: 2L milk, 2L electrolytes, 2L milk

DAY 4: 2L milk 3 x daily.

Prevention of Scours

  1. COLOSTRUM!! Longer feeding = better protection.

  2. Do not shift calves between pens/mobs

  3. Avoid stress and overcrowding

  4. Hygiene - clean boots with disinfectant between pens, wear new gloves, wash hands etc

  5. Appropriate calf sheds – draught free, solid partitions, seperate isolation/sick pens, adequate ventilation

  6. Pre-calving nutrition for cows – ensures good quality colostrum from cows

  7. Rotate your calving and nursery paddocks year to year

  8. Vaccination of cows with Salvexin and Rotavec

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