Metritis

The uterus is enlarged and flaccid, with a watery, fetid, red-brown to off-white purulent discharge. More severe cases show systemic illness: dullness, poor appetite, reduced milk yield and fever above 39.5 degrees C. Fever is an unreliable guide, as fewer than 45% of cows with metritis have one. The 2009 and 2025 reviews agree on a peak within 10 days of calving, with 21 days as the outer window; the University of Kentucky gives 10-14 days.

Metritis is inflammation of the whole uterine wall after calving, often with systemic illness. The uterus is almost always contaminated with bacteria after parturition; disease follows when organisms overwhelm uterine defences. Escherichia coli is the initial contaminant, joined by Trueperella (formerly Arcanobacterium) pyogenes, Fusobacterium necrophorum and Prevotella species, often as mixed communities. Endometrial Toll-like receptors detect bacterial lipopolysaccharide and trigger release of cytokines and chemokines. Neutrophil function is impaired around calving, and negative energy balance weakens it further. Inflammation delays uterine involution, suppresses LH release, slows growth of the first dominant follicle and shifts endometrial prostaglandin output from the F to the E series, disrupting ovarian cycles.

Metritis is a disease of the recently calved dairy cow, and sources differ on how common it is: a University of Kentucky extension article puts it at about 12% of fresh cows, whereas a 2009 review states uterine disease in the first week after calving affects up to 40% of dairy cows. Risk is higher after dystocia, twins, stillbirth and retained placenta. Poor transition-period nutrition, low pre-calving feed intake, crowding at the feed bunk and subclinical hypocalcaemia also raise risk by weakening immunity and uterine contractions.

Clinical endometritis: purulent discharge detectable in the vagina 21 days or more after calving, without systemic illness. Subclinical endometritis: no visible discharge but raised neutrophils in the endometrium and reduced fertility. Pyometra: purulent material retained within the uterus.

Uterus (endometrium and full uterine wall), cervix and vagina, ovaries, reproductive tract

Clean calving areas, adequate pre-calving feed intake and bunk space, sound transition nutrition and body condition, prevention of subclinical hypocalcaemia, and vitamin E and selenium supplementation.

Systemic antibiotics resolve fever in 67-77% of cows within 5-10 days; fetid discharge clears more slowly. Affected cows lose milk (about 600 lb per lactation in mature cows), conceive later and face higher culling risk.