Bovine Respiratory Disease: 4 Reasons to Use Ultrasonography in Calves

Bovine respiratory disease (BRD) remains one of the most important challenges for young calves, impacting their growth, productivity, and overall herd profitability. While clinical signs such as coughing, nasal discharge, and laboured breathing are commonly used for diagnosis, they are often unreliable, leading to misdiagnosis or late detection. This is where ultrasonography is proving to be a game-changer. Here are the top four reasons why lung ultrasonography should be in the veterinarian’s toolbox for managing BRD in calves.

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Reason #1. Lung ultrasonography is currently the best tool to detect bovine respiratory disease in calves

Looking into the performances of diagnostic tools whose objective is to detect a clinical disease is of utmost importance because it facilitates the selection of the diagnostic approach and limits the consequences of a wrong diagnosis.

To assess the effectiveness of a diagnostic method, studies frequently measure its sensitivity (i.e. the ability to identify sick animals) and specificity (i.e. the ability to identify healthy animals). When a diagnostic tool is short on specificity, some healthy animals may receive antibiotics which can accelerate the development of antimicrobial resistance. On the contrary, when a diagnostic tool fails on sensitivity, sick animals may be left untreated which is equally problematic.

As illustrated in the table below, current traditional diagnostic methods for bovine respiratory disease, such as visual examination, rectal temperature measurement or thoracic auscultation, frequently lack of sensitivity and/or specificity and this has been an issue for calves with BRD for decades.

On the other hand, available scientific data are now sufficiently numerous to confirm that lung ultrasonography provides an objective, accurate, and non-invasive way to detect lung lesions associated with BRD [1-4]. The high sensitivity and specificity levels usually associated with lung ultrasound makes it a good tool for BRD detection. Lung ultrasonography limits the risk of underdiagnosing or overdiagnosing BRD. When combined with clinical examination, it significantly improves the accuracy of diagnosis, allowing for targeted interventions and better disease control.

Reason #2. It is easily accessible to veterinarians

Advancements in veterinary technology have made portable ultrasound machines more affordable and accessible to veterinarians. Modern ultrasound devices are compact, user-friendly, and equipped with high-resolution imaging capabilities, making them suitable for on-farm use.

Veterinarians can be quickly trained to perform lung ultrasonography in calves with minimal effort. With proper training and experience, veterinarians can confidently interpret ultrasound images and provide accurate diagnoses. Unlike radiography, which requires specialized equipment and infrastructure, ultrasonography can be performed in the field without any major logistical challenges. This means that ultrasonographic examinations can be conducted during routine herd visits, allowing for real-time decision-making and immediate action.

Courtesy of Dr. A. Lisuzzo, University of Padua

Reason #3. It can reveal hidden production losses

One of the biggest challenges with bovine respiratory disease (BRD) is its impact on long-term productivity [5]. Lung ultrasonography provides valuable insights into the hidden effects of BRD. By identifying lung lesions, veterinarians can assess the true extent of the disease’s impact on their herd.

Research has shown that dairy calves with lung lesions detected by ultrasound at a young age tend to have reduced survival [6], decreased reproductive performances and lower milk production [7] compared to healthy counterparts. In a study that has been performed in 613 heifers, the association of lung consolidation at weaning with later survival was determined [6]. The results show that heifers with lung consolidation at weaning were more likely to be culled between 350 days of life and first calving than heifers without lung consolidation (hazard ratio = 4.7). Overall reproductive performance was also affected as heifers with lung consolidation at 60 days of life had a lower hazard of pregnancy compared with those without lung consolidation (hazard ratio = 0.7).



The results of a study performed in 215 female calves from 3 dairy herds in Ontario, Canada indicate that the presence of lung consolidation detected with ultrasound during the first 8 weeks of life has a long-term effect on dairy calves, manifested as a reduction by 525 kg of the milk production in the first lactation [7].

Reason #4. It allows early detection and early intervention

Early intervention is critical in managing bovine respiratory disease effectively. The longer a calf remains untreated, the more severe the lung damage becomes, leading to poor treatment outcomes and increased mortality rates. A key advantage of ultrasonography is its ability to detect BRD in its early stages, even when clinical signs are scarce.

By implementing lung ultrasonography as part of routine health monitoring, veterinarians can identify affected calves sooner and administer targeted treatments before the disease progresses. A recent study reported that a weekly lung scan of calves coupled with clinical examination can lead to early detection of BRD clinical cases, several days before most frequently used clinical scoring tools. Additionally, prompt treatment of calves with BRD was associated with a high success rate, an absence of relapse, a rapid healing of lung lesions, and a similar growth and carcass quality to untreated healthy calves [8].

Conclusion

Lung ultrasonography is improving the way veterinarians diagnose and manage BRD in calves. Given its accuracy, ease of use, and ability to detect hidden disease impacts, it has become an essential tool for modern cattle operations. By incorporating ultrasonography into routine herd health programs, veterinarians can enhance disease detection, improve treatment outcomes, and ultimately boost cattle farms productivity and profitability.

Bibliography

[1]. Buczinski S, Ménard J, Timsit E. Incremental Value (Bayesian Framework) of Thoracic Ultrasonography over Thoracic Auscultation for Diagnosis of Bronchopneumonia in Preweaned Dairy Calves. J Vet Intern Med. 2016;30(4):1396-1401. 

[2]. Buczinski S, L Ollivett T, Dendukuri N. Bayesian estimation of the accuracy of the calf respiratory scoring chart and ultrasonography for the diagnosis of bovine respiratory disease in pre-weaned dairy calves. Prev Vet Med. 2015;119(3-4):227-231.

[3]. Buczinski S, Fecteau G, Dubuc J, Francoz D. Validation of a clinical scoring system for bovine respiratory disease complex diagnosis in preweaned dairy calves using a Bayesian framework. Prev Vet Med. 2018;156:102-112.

[4]. Berman J, Francoz D, Dufour S, Buczinski S. Bayesian estimation of sensitivity and specificity of systematic thoracic ultrasound exam for diagnosis of bovine respiratory disease in pre-weaned calves. Prev Vet Med. 2019;162:38-45.

[5]. Buczinski S, Achard D, Timsit E. Effects of calfhood respiratory disease on health and performance of dairy cattle: A systematic review and meta-analysis. J Dairy Sci. 2021;104(7):8214-8227.

[6]. Teixeira AGV, McArt JAA, Bicalho RC. Thoracic ultrasound assessment of lung consolidation at weaning in Holstein dairy heifers: Reproductive performance and survival. J Dairy Sci. 2017;100(4):2985-2991.

[7]. Dunn TR, Ollivett TL, Renaud DL, et al. The effect of lung consolidation, as determined by ultrasonography, on first-lactation milk production in Holstein dairy calves. J Dairy Sci. 2018;101(6):5404-5410.

[8]. Lisuzzo A, Achard D, Valenza A, et al. Bovine Respiratory Disease in Veal Calves: Benefits Associated with Its Early Detection by Lung Ultrasonography and Its Prompt Treatment with a Single Dose of a Fixed Combination of Florfenicol and Meloxicam. Animals (Basel). 2024;14(23):3499.