Summertime for cow-calf producers is usually a low stress period of the year.  With calving season behind us and cattle out to summer pastures, it’s easy to hit cruise control and take a breather before we start to think about fall work and weaning season. 

While this can provide a much-needed break, don’t forget that there is the potential for lurking problems in pasture if we don’t remain vigilant about monitoring cattle health.  One of the most common health issues that producers face is summer pneumonia in suckling calves.  

Summer Pneumonia in the Herd

A survey of veterinarians led by AR Woolums suggested that across the plains states about one in five herds will have cases of summer pneumonia in a given year. In a related survey of beef producers by the same research group, the number of cases of summer pneumonia appeared to correlate with:

• herds that had fought scours in the calves,
• had a calving season that lasted three months or longer, or 
• that brought in orphan calves from other farms.  

In his 2015 Beefwatch article, Summer Pneumonia in Beef Calves, Dr. Richard Randall discussed a case-control study also conducted by Dr. Woolums and her research group in Nebraska, South Dakota and North Dakota beef herds to better identify risk factors for nursing calf pneumonia. 

Several risk factors were identified including:

• larger herd size, especially herds with 500 cows or more,
• intensive grazing, and 
• estrus (heat) synchronization. 

It is thought that these practices increase the number of “effective contacts” between calves, meaning they have more chances to effectively spread bacteria and viruses to one another. These practices may carry significant benefits for the beef operation, but care must be taken to manage the associated risks.  

Symptoms of Summer Pneumonia in Calves

Initial signs of pneumonia in suckling calves can be subtle and identifying affected animals is often the biggest challenge in getting them the needed treatment.  Some signs to watch for in calves:  

• Depression- calves that are not as bright and perky as you would expect, Depressed calves may look tired or drowsy, not as interested in interacting with herdmates, or slow to respond to caretakers. 
• Isolation- Calves that may be battling pneumonia can have a tendency to isolate themselves from the herd, often found lying away from busy communal areas where they can find some quiet resting places. 
• Inappetence – While difficult to directly assess this symptom, it often manifests as calves that are “hollow”" or "shrunk up” with a lack of good abdominal fill. Alternatively we may observe cows with over-full udders when they are not being nursed as regularly or robustly. 
• Cough- While commonly considered a symptom of respiratory disease, a cough is not nearly as reliable as one would think. So while it is a good symptom to look for, make sure that it is not the primary indicator being used to evaluate calves for illness. 
• Nasal/Ocular Discharge- much like a cough, nasal and/or ocular discharge can be a good indication of pneumonia, but absence of this symptom should never be viewed as a reason not to consider pneumonia in a calf.  
• Fever, Increased Respiratory Rate and Difficulty Breathing- once you identify a potential pneumonia victim, you are likely to observe these more overt symptoms during handling for treatment. It is always a good idea to carry a thermometer and get a rectal temperature on calves that are caught as the presence of a fever is generally one of the most reliable indicators of pneumonia in young calves.   

Contact Your Veterinarian

Once a producer has identified pneumonia cases in their herd, a conversation with their herd health veterinarian is the next important step.  Your veterinarian can help you make decisions on the most effective plan for treatment, as well as discuss prevention options.  

Early identification of affected calves is important, as treatment is usually effective when administered early in the course of illness, but can become much less successful if the disease is allowed to progress.  

In the event that a calf suspected of having pneumonia dies,  your veterinarian can generally diagnose this condition with a high level of certainty during a post-mortem exam. 

• Having these calves posted by a veterinarian can also rule out other -possible causes of death and allow the vet to recommend the ideal course of action for future cases. 
• During the summer months it is very important to get any dead calf that will be presented for a post-mortem exam to the veterinarian as soon as possible, because the carcass will decompose rapidly in hot conditions, which may make it impossible for a vet to accurately diagnose.    

Prevention

As with any herd health issue, prevention is generally more useful than treatment, so what can producers do to avoid pneumonia issues on summer pasture?  

• Appropriate Vaccination Programs – While no vaccination program is 100% effective, having a good vaccination program that is well administered can help decrease disease incidence.  Also important is how vaccinations are administered and handled during working events; vaccination is only effective if vaccines do not get damaged by heat, sunlight, or contamination prior to administration.   
• Good Colostrum Management – like it or not, much of what makes our calves successful happens in the first 24 hours after birth; assuring cows have the tools to build adequate quality colostrum, and being diligent in making sure every calf receives adequate colostrum can greatly affect its susceptibility to disease for the rest of its life. It is important to understand that the immune support a calf receives from mom in the form of colostral antibodies wanes in mid to late summer, making this a critical window when calves can be more susceptible to disease, which is where that vaccination derived immunity will be critical.   
• Mineral Supplementation- recent research shows that calves consume more mineral than what most producers expect on summer pasture, even at very young ages.  Both Macro and Trace minerals are critical in immune function and vaccine responses; having both cows that are adequate in mineral status and calves that are able to consume the mineral that they need when maternal derived supplies run out is critical for both adequate response to vaccination and resilience to disease exposure.   
• Attention to Energy and Protein Nutrition- Both energy and protein intake are critical to support and maintain immune function and disease resilience, it's important to understand that young calves are not as efficient ruminants as the cows, and as pasture quality decreases in late summer/early fall extra attention may need to be given to making sure calves are getting what they need nutritionally to maintain health. 

Interviews with the authors of BeefWatch newsletter articles become available throughout the month of publication and are accessible at https://go.unl.edu/podcast.  You can subscribe to the BeefWatch newsletter here: http://go.unl.edu/Beefwatch_subscribe