You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Injury to the myocardium (myocardial contusion or necrosis; traumatic myocarditis) occurs in dogs but it is difficult to diagnose because there are no specific clinical signs attributable to the disease. Measurement of cardiac troponins has been shown to be a useful biochemical marker.

Blunt trauma to the chest is a common occurrence in dogs due to road traffic accidents, falls and kicks. Injuries which often accompany such trauma (eg fractured ribs, pulmonary haemorrhage, pneumothorax or diaphragmatic hernia) are readily recognised by their clinical presentation and detection on screening radiographs or ultrasound. Injury to the heart is more difficult to recognise, unless the animal dies and lesions are found at post-mortem. 

The clinical implications are serious because myocardial injury can lead to cardiac failure or fatal arrhythmias. Recognition of the presence of myocardial injury should be taken into consideration when formulating a prognosis, and in decision making for the management of trauma cases, particularly regarding the work-load to be put on the heart by exercise. 

A group of workers have reported the successful identification of myocardial disease in canine trauma patients by measuring cardiac troponin concentrations in blood - notably cTnI*. Cardiac troponins (eg cTnI and cTnT) are thin filament-associated regulatory proteins of heart muscle and cTnI is uniquely present in myocardial tissue. In this study 18/33 (55%) dogs had increased serum cTnI concentrations above the normal reference range, and in 16/33 dogs (48%) concentrations exceeded 2.0 ng/ml - the level recognised in humans as depicting significant myocardial cell injury. Normal dogs did not have any detectable cTnI in their serum.   The ELISA test used in this study has been developed for use in humans, but the similarity between canine and human cTnI is so great that the authors consider the test reliable for use in dogs. The lower detection limit of the test is 0.5ng/ml, and reference values were derived from 40 control dogs in the study.

The authors concluded that myocardial injury is a frequent event in dogs receiving blunt trauma to the chest and that analysis of serum cTnI was the most sensitive indicator for detecting the presence of myocardial injury, and more reliable than ECG or other biochemical parameters including cTnT or the MB enzyme (CK-MB).

(* Schober K.E et al Journal of Veterinary Cardiology Vol 1, No 2, December 1999 p17)

Last updated : January 2016