Endometritis (whites)

Endometritis (whites)

This is by far the commonest disease in the metritis complex. UK figures suggest that around 10 - 15 % of cows develop endometritis after calving. The figures vary greatly between farms with the best farms having <4% and the worst over 25%.

Endometritis is an infection of the endometrium only. This infection doesn't spread so cows show no signs of illness. Some cows with endometritis can be easily identified because they have discharge from the vulva with small amounts of pus adherent to the tail but a high proportion of cows, probably as high as 80%, show no discharge from the vulva.

The effects of endometritis

Endometritis has two effects on fertility. Firstly it is associated with absence of heat behaviour - delaying the onset of ovulation after calving and extending the interval between ovulations once cows have been in heat. Secondly, even when they cycle, cows with endometritis are much less likely to get pregnant because the infected uterus is a poor environment for the developing embryo.

Diagnosis of endometritis

In cases with vulval discharge, diagnosis is simple. However in the majority of cases such discharge is not apparent, so cows need to be examined more closely to identify metritis. The advantages and disadvantages of some of the commonly used techniques are summarised in Table 1.

Table 1: Methods of detection of endometritis.

Method	Advantages	Disadvantages
Manual examination of the vagina	Cheap	Slow - need for cleanliness Vaginitis, cystitis difficult to distinguish from endometritis Not all endometritis cases produce a discharge that is detectable in the vagina
Metricheck	Cheap, quick	Vaginitis, cystitis difficult to distinguish from endometritis Not all endometritis produces a detectable discharge
Vaginoscopy	More accurate than manual examination and Metricheck	Slow Not all endometritis produces a discharge
Ultrasound	Accurate detection of pus in uterus	Not all endometritis cases have detectable levels of pus in the uterus
Uterine cytology	Most accurate measure of endometritis	Cost Slow

As can be seen from Table 1 there is no ideal solution. In some circumstances it may be better to examine all cows in a group using a Metricheck device (figure 4), and in others to target ultrasound examination in those cows which have a history suggestive of a high risk of endometritis - stillbirth, twins, retained fetal membranes, dystocia and milk fever.

Treatment of endometritis

A huge amount of research has been undertaken on the treatment of endometritis; however most of the research has just added to the debate rather than settled it.

The principles of treatment are:

1. Treatment should be delayed until at least 4 weeks after calving - early treatment of otherwise well cows has shown no benefit.
2. Only two treatments have shown any evidence of effectiveness :-
   a) Prostaglandins
   b) Intra-uterine antibiotics
3. Putting disinfectants, such as Dettol or Jeyes fluid, into the uterus does not work and will often cause infertility.
4. Treatment effectiveness is not based on disappearance of discharge, but on how soon treated cows become pregnant. This is because it's not the discharge that's the problem it's the effect of the discharge on fertility.

When treating a cow with endometritis treatment choice will depend on factors such as type of discharge - is it creamy or bloody, does it smell, is there mucus in the pus - and whether the cow has been in heat. To be effective treatment has to have time to work; so the ideal scenario is that cows that are at high risk of endometritis are presented to the veterinarian at least two weeks before the end of their planned waiting period (often 42-56 days after calving), and that cows that are not showing oestrus are picked up and examined as soon as possible.