Iain Carrington: Cows susceptible to infection after calving

Iain Carrington looks at the common infections which can affect cows after calving

Iain R Carrington
Iain R Carrington

After calving, invasion of the uterus by bacteria is common. This usually resolves itself as the uterus contracts and returns to its non-pregnant state.

Unfortunately in a significant number of cases, the infection does not clear; often after bad calvings, twins, retained membranes, metabolic conditions and other disorders. This can cause one of the following:

Metritis – This usually occurs within the first two weeks after calving and can be severe. The cow has no appetite, a high temperature and is often toxaemic; it is also frequently associated with metabolic disease and left displaced abomasum.

Clinical endometritis – A chronic infection of the uterine lining often referred to as ‘whites’. It is characterised by an abnormal discharge which can often be seen crusted on the tail next to the vulval lips. This condition is typically seen around three weeks post-calving.

Subclinical endometritis – Chronic inflammatory condition of the uterine lining caused by low-grade infection or scarring. May only be detected by examining a sample of cells from the uterine lining, although this is not generally a practical option.

Risk factors associated with disease should be minimised. These include:

Compromised immunity – This can be caused by metabolic disease or prolonged high levels of progesterone (often seen in cows with uterine infections). This can be discussed with your vet.

Damage to the reproductive tract at calving.

Poor hygiene and management at calving – Anatomy and loose faeces mean cows are more prone to contamination than other species.

Treatment of metritis is often intensive, requiring antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), fluids and possible flushing of the uterus. Identifying the cows at greatest risk of endometritis means that a more proactive approach can be taken towards control and treatment.

In dairy herds it is practical to perform checks at 21-30 days post-calving to identify those cases that require treatment quickly. At these checks vaginal mucous can be examined for colour, consistency and odour; the cervix size can be assessed and rectal examination can assess the size of the uterus. Treatment is carried out with intra-uterine antibiotics with or without the use of injectable prostaglandin F2a which should remove the immunosuppressive effect of prostaglandin.

To effect control of endometritis it is necessary to identify the at-risk cows, use post-calving checks, early treatment and optimise the health and nutrition of cows in the transition period. Damage to the uterus from infection can lead to delayed first oestrus, lower conception rates, longer interval until pregnant, increased culling, greater likelihood of health problems and reduced milk yield.

Although this information relates mainly to dairy cows, sucklers can be affected, causing increased calving intervals and culling.

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