- Congestive heart failure can be due to bacterial infections of the heart and surrounds arising from blood infection or from penetrating foreign bodies (e.g. a wire) or, occasionally, from poisoning (e.g. monensin)
- The heart is less able to pump blood and so fluid builds up in dependent tissues, such as the head, neck and brisket and the legs of cattle. The swelling of tissues with excess fluid is called oedema.
- Affected cattle have reduced exercise tolerance and may also show signs of infection (fever, depression, inappetence).
- Cattle with oedema are condemned at processing.
- Bacteria entering the heart from the bloodstream often follow unhygienic procedures (such as marking) or from generalised infection (such as pneumonia). The bacteria damage the heart valves, which leak, resulting in fluid build-up in the tissues.
- Bacteria can enter the heart sac (pericardium) by a penetrating wound, typically a wire or nail eaten by the animal. The wire can behave like a grass seed and penetrate the reticulum (second stomach), the diaphragm and pericardium, establishing infection. This is called traumatic pericarditis. Pus inside the pericardium prevents the heart from filling leading to fluid retention.
- Toxic doses of Ionophore feed additives produce heart muscle failure. The weakened muscle cannot pump blood, and this results in fluid retention.
- Exercise intolerance,
- Swelling under the jaw (bottle jaw), the brisket and legs.
- Occasionally fluid retention is so severe the abdomen will expand.
- Clinical signs are often diagnostic. Always check the mouths of cattle with bottle jaw signs to ensure they do not have a foreign body stuck in the mouth.
- Veterinary examination can confirm if the heart is involved in swelling.
- Meat inspection will identify if there is excessive fluid build-up in the tissues and muscle. Affected carcases are condemned.
- Mild cases of infective congestive heart failure may be treated with antibiotics. Cattle with traumatic pericarditis or mild forms of ionophore poisoning should be sent for salvage slaughter if fit to travel and generalised swelling (oedema) is not present.
- Cattle with severe congestive heart failure should be immediately destroyed.
- Consider vaccination against serious respiratory disease, especially for feedlot-bound cattle.
- Minimise contamination of grazing areas or feeding areas with metallic rubbish (to prevent risk of traumatic pericarditis).
- Avoid Ionophore toxicosis by ensuring correct doses are delivered using an appropriate supplement feeding system.