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Cardiac diseases of cattle (Proceedings)

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Aug 01, 2011

Congenital, infectious, neoplastic, nutritional and toxic causes of cardiac disease are occasionally encountered in primary and referral bovine practice. The presentation accompanying these proceedings will review the most commonly encountered conditions with an emphasis on dairy cattle in the Northern United States. In addition the results of a small retrospective study on cases of idiopathic hemorrhagic pericarditis will be presented describing the diagnosis, management and outcome for adult cattle with this condition, based upon clinical cases seen at the University of Wisconsin's Veterinary Medical Teaching Hospital in recent years.

Pericardial disease

Septic pericarditis remains the best documented and most commonly reported pericardial disease in cattle. Within the literature it is most commonly attributed to foreign body penetration through the diaphragm, originating from the reticulum, although the potential does exist for extension of septic intra-thoracic disease independent of reticuloperitonitis. Clinical experience would suggest the latter is far less common, although occasional cases of septic pleural or pulmonary disease will extend to involve the pericardial sac. Aseptic pericardial effusions are most commonly associated with cardiac neoplasia (typically lymphosarcoma) or the recently documented condition of idiopathic hemorrhagic pericardial effusion1,2. Rare cases of cardiac neoplasia other than lymphosarcoma such as mesothelioma and chemidectoma are documented and these can lead to clinically significant accumulations of pericardial fluid and resultant tamponade3.

Idiopathic hemorrhagic pericardial effusion

There have been 2 reports in the literature1,2 of this condition and we have seen a number of cases admitted to our hospital during the last 5 years at the University of Wisconsin. It is an unusual condition but over the last 5 years admissions with this disease have approximately equalled the number of septic pericarditis cases in our hospital. It is most noteworthy from the perspective of outcome and longevity for affected cattle following treatment. As has been previously noted by Firshman et al (2006) pericardial drainage and anti-inflammatory medication can bring about prolonged (>1 year) remission. Our experiences have been similar suggesting that the common presenting signs and examination findings of cardiac tamponade and congestive failure can be reversed for sufficient time frames to allow for reproductive salvage and even a return to productivity in some mature dairy cattle. We have followed some cattle with this condition for several years and a few have gone on to develop a form of epicardial lymphosarcoma, quite distinct from the typical right atrial lymphosarcoma occasionally seen in association with BLV infection. Part of the conference presentation accompanying these proceedings will detail the case presentation, diagnosis, and outcome for cattle affected with this condition.

Endocardial disease

The most common endocardial disease encountered in cattle is septic endocarditis. Most cases are vegetative and valvular in location although concurrent mural endocardial lesions may also be seen. Mural endocarditis in the absence of valvular lesions is extremely rare. The retrospectives that have been published list the right atrioventricular (AV) valve as the most commonly affected, and the left AV valve being the next most likely to be involved4. Microbiological investigation of valvular lesions at post mortem and the blood of affected cattle ante-mortem have demonstrated that Arcanobacterium pyogenes is the most commonly cultured organism3.