Auscultation is considered as a critical component of the veterinary clinical examination for the diagnosis of bovine respiratory disease but studies have shown that a stethoscope detects only around 5 per cent of cattle with lung consolidation.
In bovine respiratory diseases, modern portable ultrasound machines provide the veterinary practitioner with an inexpensive, non-invasive tool with which to examine the pleural surfaces and superficial lung parenchyma in less than five minutes.
Most cows with chronic suppurative pulmonary disease have a normal rectal temperature on presentation but this varies up to 39.2°C. Cattle have an increased respiratory rate above 40 breaths per minute with an obvious abdominal component. There is frequent and productive coughing, halitosis, and a purulent nasal discharge most noticeable when the head was lowered.
The economic implications of chronic suppurative pulmonary disease include:
Chronic suppurative pneumonia is a difficult diagnosis in farm animal practice because the cow has often been treated by the farmer with antibiotics. Infectious bovine rhinotracheitis and lungworm should be considered as well as chronic bacterial infections that cause poor production and weight loss such as peritonitis, endocarditis, pericarditis, liver abscessation, pyelonephritis, and hepatocaval thrombosis.
Common differential diagnoses include:
It proves difficult to differentiate increased audibility of normal breath sounds from wheezes; no crackles were detected over lung pathology identified ultrasonographically in several studies. Ultrasonographic examination has been shown to accurately define the distribution and nature of lung pathology in those cows with advanced disease that have not responded to antibiotic therapy.
Trueperella (formerly Arcanobacterium) pyogenes is the most common isolate from lung tissue samples of adult cattle with chronic suppurative pulmonary disease at necrospy. Treatment with procaine penicillin for 21-42 consecutive days has resulted in marked improvement with return to normal appetite and improvement in body condition in cows where lesions did not extend more than a combined total of 35-40 cm above the level of the olecranon when lesions on both sides of the chest are added together (see below).
This antibiotic treatment regimen is consistent with RUMA recommendations on the responsible use of antibiotics whereby fluoroquinolones, third and fourth generation cephalosporins and long acting macrolides have an important place in the therapeutic armoury for serious diseases of humans.
Prevention of chronic respiratory disease involves vaccination, and prompt veterinary treatment and monitoring of pneumonia cases in growing cattle. Closely monitor all antibiotic treatments. Maintain BVD/MD free herd status or vaccinate herd.
Scott P.R. (2013) Ultrasonographic findings in adult cattle with chronic suppurative pneumonia. In Practice 35, 460-469
Scott P.R. (2013) Clinical presentation, auscultation recordings, ultrasonographic findings and treatment response of 12 adult cattle with chronic suppurative pneumonia.
Irish veterinary Journal 66, 5 doi: 10.1186/2046-0481-66-5
Buczinski S, Forté G, Francoz D, Bélanger AM. (2014) Comparison of thoracic auscultation, clinical score, and ultrasonography as indicators of bovine respiratory disease in preweaned dairy calves. Vet Intern Med. 28:234-42. doi: 10.1111/jvim.12251.
NADIS hopes that you have found the information in the article useful. Now test your knowledge by enrolling and trying the quiz. You will receive an animal health certificate for this subject if you attain the required standard.