Neonatal Calf Diarrhea

Neonatal calf diarrhea (calf scours) is an enteric disease complex

Newborn calves are susceptible to neonatal calf diarrhea (calf scours) especially during their first 28 days of life. Bacteria, viruses and parasites, by attacking the lining of the calf's intestine, give rise to diarrhea. This in turn decreases the absorption of essential nutrients from milk and leads to weight loss and dehydration. If the disease level is severe, the calf may die; however, even calves that survive will have poorer performance for the remainder of their lives when compared to healthy calves.

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Etiology
Rotavirus, coronavirus, bacteria (K99 E. coli; Clostridium perfringens Type C, Salmonella spp.) and parasites (cryptosporidia, coccidia) are the most common causes of neonatal calf diarrhea. Controlling rotavirus, coronavirus and E. coli can significantly reduce losses due to calf scours.
Contributing factors that can allow the emergence of the disease are:
Inadequate quantity and/or quality of colostrum.
Erratic feeding of calves resulting in over-consumption of milk. This may create an enteric environment in which certain bacteria thrive, causing severe scours.
Difficult calving.
Poor sanitation.
Cold, wet weather.
Overcrowding in calving area.

Clinical Signs

Depending on the cause, calf scours can occur anytime from the first few hours after birth up through the first month to six weeks of life. First-calf heifers often produce lower quality and lower quantity colostrum and thus their calves may be more likely to scour. Signs may include:

Diarrhea, sometimes containing blood or mucus
Dehydration as evidenced by loose, thickened skin.
Weight loss.
Weakness.
Poor growth.
Rough hair coat
Death 12-48 hours after onset of disease.

The table below highlights some of the signs associated with particular infectious agents.

Scours agent	Age of onset	Signs
Rotavirus	possible: 0–28 days; most common: 1–6 days	watery brown to light green feces, blood and mucus
*K 99 E. coli* bacteria**	most common: 1–7 days	effortless passing of yellow to white feces
Coronavirus	possible: 0–28 days; most common: 7–10 days	watery, yellow feces
*Clostridium perfringens* Type C	most common: 7–28 days	sudden death, blood-tinged diarrhea
Cryptosporidia	most common: 7–21 days	watery brown to light green feces, blood and mucus
Coccidia	most common: 7 days and after	blood-tinged diarrhea
*Salmonella spp.*	most common: 1–7 days	similar to E. coli; yellow to white feces

Diagnosis

Diagnosis can be made on clinical signs and epidemiology, but additional examinations are often needed (bacteriology, fecal smears, post-mortem examinations) to determine the exact cause.

Treatment

Successful treatment of calf scours depends upon rapidly rehydrating scouring calves.
Oral rehydration products help restore fluid balance, lost electrolytes and essential nutrients.
In bacterial scours cases, oral or injectable antibiotic therapy may be advised.

Prevention
Vaccination of the cow against the common enteric pathogens prior to calving to provide disease protection for the calf through the colostrum (first milk).
If the cow herd has not been vaccinated, consider using an oral vaccine in newborn calves prior to nursing to provide immediate protection in the gut.
Reduction of exposure of newborns to infectious agents:
Separate healthy pairs from sick calves immediately;
Be sure equipment, boots and hands are thoroughly cleaned after handling sick animals.
Segregating cow-calf pairs by age (Sandhills Calving System)
Maintaining clean pens and facilities
Reduction of stress on cows and calves:
Assist with calving as necessary, especially with heifers;
Keep animals as clean and dry as possible.
Adequate nutrition of the mother cow.
Make sure calves start nursing as soon as possible after calving to get adequate colostrum (10% of the body weight in the first 24 hours with at least 2 quarts during the first 6 hours)

Economic Impact
USDA estimates that between 4 and 25% of all calves will die from scours each year in the U.S.1

Economic losses can also be attributed to:
Long-term effects on health and productivity of surviving calves
Treatment and labor costs: antibiotics, milk replacer, oral rehydration