Lesions of Right Heart Failure and Ascites in Broiler Chickens

Abstract

A naturally occurring cardiomyopathy in broiler chickens from a single Ontario farm was studied in order to define the morphologic changes. Gross and histologic features of affected birds were compared with those in age-matched control penmates. Body weight and weight and volume of individual cardiac chambers were measured. Histologic sections of 18 different tissues were examined, and lesions observed were scored subjectively. Affected birds were stunted and had marked right ventricular dilation and hypertrophy, atrial hypertrophy, ascites, pulmonary congestion and edema, and hepatic capsular fibrosis. Microscopic changes in the heart of affected birds were mild and did not suggest a specific cause of heart failure. Lungs had marked hypertrophy of parabronchial smooth muscle and collapse and apparent loss of associated air capillaries. Other histologic changes observed were thought to be the result of passive congestion of viscera caused by right heart failure and chronic debility. Although the specific etiology of this condition could not be determined, it was felt that this syndrome was unlikely to have been the result of any of the commonly recognized causes of congestive heart failure and ascites in broilers.

Ascites in poultry

“…All the clinical signs in PHS, except lung oedema and hypoxia resulting from PH, and all the pathological lesions, except some of those found in the heart and lung, are the result of increased venous pressure from the RVF (Wilson et al, 1988). The signs and macroscopic and microscopic lesions described are identical to those found in valvular insufficiency or RVF from any cause.…”

“…Hydropericardium and ascites from heart lesions associated with vitamin E-selenium responsive disease (nutritional muscular dystrophy) from free radical damage, has been described in turkey poults and waterfowl (Wilson et al, 1988;Austic & Scott, 1991). Furazolidone-induced cardiomyopathy has been used as a model of dilated cardiomyopathy and has been studied extensively (Staley et al, 1978;Ferron & van Stratum, 1982;Mirsalimi et al, 1990;.…”

“…Many general articles have been written on ascites or the ascites syndrome describing the incidence, lesions and various causes of ascites (Neumann et al, 1975;Bergmann et al, 1979;Estudillo-Lopez, 1980;Lopez-Coello et al, 1982;Agudelo, 1983;Ashfaque et al, 1983;Huchzermeyer, 1984Huchzermeyer, , 1985Wideman, 1984Wideman, , 1988Da Silva, 1985;Rivera, 1985;Pozos et al, 1986;Hernandez, 1987;Odom et al, 1987;Riddell, 1987;Hoerr, 1988Hoerr, , 1989Wilson et al, 1988;Canese et al, 1989;Cowen, 1989;Gallazzi, 1989;Maxwell, 1990a).…”

Right ventricular hypertrophy, right ventricular failure and ascites in broiler chickens caused by Amiodarone‐induced lung pathology

“…Cartilaginous pulmonary emboli, collagen and mineralised masses are common in the lung of broiler chickens and are present in large numbers in some broilers with ascites (Wilson et al, 1988). They may block up to 20% of the respiratory parenchyma of some lobules.…”

Histopathology of the lymphatic system in ascitic broilers

“…Since systemic venous pressure (SVP) must be overcome before liver lymph can flow, variations in SVP may affect lymph flow rate and therefore the rate of fluid accumulation within the liver. Edema develops when lymph does not return to the venous circulation at a rate equal to the rate of capillary filtration (Wilson et al, 1988). Ascitic broilers develop edema as well as an increased central venous pressure while undergoing PHS (Bezuidenhout, 1988;Sakumi et al, 1996) A further study should be made of the relationship between the histomorphologic changes of lymphatic system, lymphatic flow and pressure in response to central venous pressure to assess the severity of broilers during the pathophysiology precession leading to ascites.…”