Endometritis – inflammation of the lining of the uterus – is a common cause of infertility in mares, but there can be challenges in diagnosing it.
While the examination of biopsies from the uterine lining is considered the gold standard, there are shortcomings. The waiting time for test results makes it inappropriate for immediate treatments and, routinely, only one biopsy is collected.
However, results obtained from a single biopsy sample may be misleading, researchers noted in the journal Acta Veterinaria Scandinavica. A study performed after slaughter showed that a single biopsy was not enough to determine the severity of degenerative changes in the uterus with enough accuracy.
Another post mortem study revealed that evaluation of inflammation using both cytological and histological techniques did not give the same results in different sampling sites.
Researchers in a Polish study set out with two aims – to determine whether testing for two acute-phase proteins in blood samples might prove to be a useful diagnostic tool for endometritis; and to explore the usefulness of flushing the uterus with one litre of sterile saline as a diagnostic method for the condition.
For the study, Monika Sikora and her colleagues used 53 sub-fertile Icelandic mares suspected of having subclinical endometritis.
Endometrial swabs and a lavage, in which a litre of sterile saline was flushed through the womb of each mare, were performed for cytological and bacteriological examinations. Two endometrial biopsies were also taken.
Blood samples were collected 12 to 24 hours after ovulation to determine the concentrations of acute-phase proteins serum amyloid A and haptoglobin in the 53 subfertile mares. The results were compared to those of a control group comprising 20 non-pregnant mares who later conceived.
Twenty-five mares were classified as positive for endometritis based on the biopsy results.
Measurement of serum amyloid A and haptoglobin did not prove useful for diagnosis of subclinical endometritis in the mares, the study team reported.
However, the researchers noted a correlation between cloudiness of the efflux – the saline collected from the lavage – and the results of the other tests that were indicative of inflammation in the uterus.
Cloudiness in the fluid collected by lavage were not consistently indicative of infection, they reported, but when present they indicated a high probability of inflammation in the uterus.
“We conclude that if cloudy efflux or debris is seen in the lavage fluid, when one litre of fluid is used, the mare has endometritis and requires treatment.”
Sikora was joined in the study by Jarosław Król, Marcin Nowak, Tadeusz Stefaniak, Gudmar Aubertsson, and Roland Kozdrowski. All are affiliated with Wroclaw University of Environmental and Life Sciences in Poland except for Gudmar Aubertsson, who is with Dýralæknir Sandhólaferja.
The usefulness of uterine lavage and acute phase protein levels as a diagnostic tool for subclinical endometritis in Icelandic mares
Monika Sikora, Jarosław Król, Marcin Nowak, Tadeusz Stefaniak, Gudmar Aubertsson and Roland Kozdrowski.
Acta Veterinaria Scandinavica 2016 58:50 DOI: 10.1186/s13028-016-0233-4