Temperature Swings Present Pneumonia Challenges
With temperatures set to drop in many parts of the country, now is the time to be proactive in monitoring calves for symptoms of pneumonia. Young calves have many odds stacked against them, including a weakened immune system.
Calves vs. Pneumonia: The Survival Challenge “Calves are born with naive immune systems," explains Jeff Tyler, University of Missouri veterinarian. "Dairy calves, in particular, have a whole tally of strikes against them the minute they hit the ground."
For example, dairy calves are challenged because cows calve on most dairies year-around. Unlike beef operations, which usually have an annual calving season, dairies have a constant supply of new susceptible hosts. And those new calves often are born in the same facilities; start their lives close to potential contamination sources; and share the same environment with adult animals. "Infectious organisms can become amplified over time as they are passed from calf to calf, until they eventually become overwhelming," Tyler explains. "The calves essentially become disease factories."
"The dairies I've seen with the healthiest calves are minimalists," says Tyler. "They don't spend a lot of time or money looking for 'silver bullets.' Instead, they focus on the basics, and do the same things very well, every day."
Fever Common In Calves with Pneumonia Most calves that have pneumonia will have a fever (rectal temperature over 103 degrees) and a rapid respiratory rate (often over 60 breaths per minute). Often, I will look at the calf before disturbing it to see if it is breathing fast as this is a very sensitive indicator of pneumonia. All calves that are suspected of having pneumonia must have their temperature taken. Listening to the lungs with a stethoscope can reveal increased or scratchy crackling breath sounds. Coughing and nasal discharge is also a sign of pneumonia; however, this can also be a sign of poor ventilation and "stale" air. A calf that is coughing without a fever or any change in respiratory rate may just need fresh air and not antibiotics!
Tips To Keep Pneumonia At Bay Carrie Bargren, practicing dairy veterinarian at River Valley Veterinary Clinic, Plain, Wis advises her clients to take the following measures to prevent pneumonia in young calves:
Vaccination – Dry cows can be vaccinated for virtually all of the viral pathogens that cause pneumonia, and the antibodies for them then can be transferred to calves via colostrum. In addition, she said, “a good intranasal vaccine at birth will stimulate the tissues in the airways to make antibodies and be ready to kill respiratory pathogens before they enter the body, providing additional protection for the calf for 4-6 weeks.” She suggests a booster of intranasal vaccine at weaning.
Colostrum delivery – Colostrum is the only immune protection calves have for the first few weeks of life. Bargren recommends feeding 4 quarts within 6 hours after birth, and monitoring colostrum quality with a refractometer. Checking calves for total proteins (TP) to screen for Failure of Passive Transfer (FPT) of immunity is advised to monitor colostrum management.
Housing – “Clean air and deep bedding are the most important factors in preventing disease through housing management,” said Bargren. “Proper ventilation systems in calf barns will bring in clean air and remove contaminated air.” She recommends at least 26 square feet of resting space for calves in hutches or individual pens, and at least 30 square feet per head in group pens. Regardless of type, she said shelter systems should protect calves from extreme heat, cold, wind chill, rain, dust and aerosolized pathogens, all of which can stress immunity.
Nutrition – “Proper nutrition is required for healthy growth rates and to sustain immune function,” said Bargren. “Adjust volume to accommodate for cold temperatures.”
How to Prevent Pneumonia
Waneata Mehlenbacher, calf manager at Roll-N-View Dairy near Nunda, N.Y., shares tips preventing pneumonia.
Feed enough milk: The industry standard of 2 quarts twice a day may not be adequate under some circumstances. Leadley says the energy demands for calves to keep warm in extremely cold weather can require all of those nutrients and more, leaving nothing for growth. Extreme heat stress can cause similar problems. Starvation is a form of stress, which predisposes calves to pneumonia, he explains.
Keep age groups separated: Contact with older animals that have more fully developed immune systems can cause problems for the calves, particularly if those animals are stressed by calving, sickness or weaning. To help prevent this interaction, place calves in hutches in a row from youngest to oldest.
Minimize weaning stress: "New surroundings, commingling and ration changes make weaning an opportunistic time for pneumonia bugs to take over," says Tyler. Don't add to that stress by ear-tagging, tattooing, dehorning and/or castrating at weaning time.