Calf Scours and Pneumonia: Prevention, Electrolytes and When to Call the Vet

Young dairy calves are fragile. Their immune systems are not fully developed, and they face a gauntlet of germs in their first weeks. Diarrhea, called scours, and pneumonia account for most of the sickness and many of the deaths in pre-weaned calves. Both are largely preventable, and both are much easier to handle when caught early. A calf that is dehydrated and cold, or one that has been sick for days, is far harder to save.

This guide explains the basics of prevention and early response. It is general information and not a diagnosis or treatment plan, and your veterinarian should set protocols for your calves and any drugs used. If you want to find calf management workshops near you, agriculture.directory can help you find agriculture events in your area.

The Scale of the Problem

A South Dakota State University Extension article, Calf Scours: Causes, Signs, Prevention, and Management, reports that USDA's National Animal Health Monitoring System found that digestive problems such as scours accounted for about 14 percent of losses in calves under three weeks old in its 2007 to 2008 study. Cornell Cooperative Extension notes that raising a heifer from birth to calving is one of a dairy operation's largest costs, which is why losing calves, or raising ones that have been sick, is expensive. Read the Cornell Cooperative Extension fact sheet on calf scours for more.

What Causes Scours

Scours has several causes, often working together.

• Infectious agents. Bacteria such as E. coli and Salmonella, viruses such as rotavirus and coronavirus, and parasites such as Cryptosporidium and coccidia.
• Nutritional causes. Cornell notes that dietary imbalances, such as too much lactose or protein in the liquid feed or rapid changes in diet, can cause scours.
• Environmental stress. Cold, wet weather, crowding and dirty pens favor disease and weaken calves.
• Weak immunity. A calf that did not get enough good colostrum is much more likely to get sick and die.

The First Line of Defense: Colostrum

Every extension source puts colostrum first. Calves are born with almost no antibodies and depend on colostrum for them. Our colostrum guide covers how much, how fast and how to check that it worked. Colostrum cannot make up for a dirty environment, but a calf with good antibody levels in a clean pen can fight off exposures that would sicken a calf without them.

Cleanliness From Birth

• Clean calving area. Our calving guide covers keeping the pen clean.
• Clean colostrum handling. Contaminated colostrum can carry germs that make calves sick.
• Sanitize feeding equipment such as bottles, nipples, buckets and tubes after every use.
• Deep, dry bedding. Calves should rest on a clean, dry surface.
• Do not overcrowd. Cornell notes that adequate bedding and ventilation and not overcrowding group calves reduce pathogens in the environment.
• Handle sick calves last, and wash hands and boots between pens.

Spotting a Sick Calf Early

A healthy calf is alert, stands quickly, eats eagerly and has a clean nose and bright eyes. Check every calf at every feeding. A calf that is slow to drink, has sunken eyes, cold ears, loose or watery manure, stands with a hunched back or does not rise is in trouble. Early detection matters because, as Cornell explains, oral electrolyte therapy works only while the calf is still strong enough to absorb it.

Oral Electrolytes

Scours causes loss of water and electrolytes, leading to dehydration and a shift in the body's acid-base balance. Extension sources agree that the first treatment for a scouring calf that can still stand and drink is oral electrolyte solution. Follow the label mixing instructions exactly. Too much powder can harm the calf. Cornell advises that electrolytes are a supplement to rehydrate the calf and are not a substitute for nutrition, and that a calf receiving electrolytes should not be taken off milk, because milk provides energy and protein. Some programs advise feeding electrolytes separately from milk rather than mixed in it, so follow your veterinarian's instructions and the product label.

When Oral Fluids Are Not Enough

A calf that cannot stand, is unresponsive, has cold extremities or has very sunken eyes may be severely dehydrated. Extension sources note that when dehydration is severe, oral electrolytes may not be absorbed and intravenous fluids are needed. This is a veterinary emergency. Call your veterinarian right away. A common farm guideline, such as one published by Dairy Australia, suggests seeking advice if more than 10 percent of calves are sick or more than 3 percent die before weaning. Your veterinarian can set targets for your farm.

Pneumonia

Pneumonia is the other major calf disease. Signs include fever, rapid or labored breathing, cough, nasal discharge, droopy ears and reduced appetite. Risk factors include poor ventilation, damp or drafty pens, crowding, stress from weather or transport, and inadequate colostrum. Fresh air without drafts is the key, which means good ventilation above calf level and dry bedding. Do not close a calf barn so tight that ammonia and moisture build up. Treat pneumonia early, since lung damage can cut growth and later milk production. Your veterinarian can advise on treatment and on vaccines for respiratory pathogens.

Antibiotics and Vaccines

Antibiotics help with bacterial infections but do not cure viral scours, and overuse contributes to resistance. A veterinary column in Dairy Herd advises using antibiotics only as recommended by your veterinarian. Vaccination of dams before calving can raise antibody levels in colostrum against certain scours agents, and some calf vaccines are available. Ask your veterinarian which vaccines fit your herd and when to give them. Always follow the label and any withdrawal times.

Protect People

Several causes of calf scours, including Salmonella and Cryptosporidium, can infect people, especially young children. Wear gloves, wash hands thoroughly, keep children away from sick calves and do not eat or drink in calf areas.

Keep Records and Review

Record every sick calf, the signs, treatment and outcome. Patterns, such as a cluster of scours at a certain age, point to the cause. Genetic evaluations now include calf health traits in some systems, as discussed in the guide to genomic testing, but management remains the main lever. Raising healthy heifers also affects costs, as the heifer growth guide shows.

Common Mistakes

• Weak colostrum program. Everything else depends on it.
• Dirty bottles and pens. They spread scours.
• Stopping milk during scours. The calf needs energy.
• Waiting too long to call the vet. Down calves are hard to save.
• Tight, stuffy housing. It invites pneumonia.

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