P1130057

1.3.4.5 Pyo-, muco- and urometra

Pyometra represents a particularly severe form of endometritis. Its ultrasonic image features an extreme dilatation of the uterus (Fig. 1.109). Through this the endomettial folds are stretched and the interface be-tween the uterine contents and the wali is smooth. Within the secretions of pyometra there are usually intensive reflections which increase in density ventrally. This is caused by the sedimentation of increased amounts of cellular components as well as the increa-sing consistency of the pyometra fluid in the uterus.

The ultrasound image of the urinary bladder can look much łike that of a pyometra (Fig. 1.110). Due to the high viscosity of eąuine urine the luminal contents of the urinary bladder show an echo pattem with inten-sive reflections which can be confused with that seen in a pyometra. The appearance of the bladder can also be confused with a slightly cranially dilated uterus. Since this can lead to misinterpretations, a pyometra should only be diagnosed if two completely separate, closely opposed hollow organs can be demonstrated. It is im-portant to depict the entire bladder wali without any in-terruption so as to ensure that there is no connection to the morę cranially positioned hollow organ.

If difficulties are experienced in differentiating be-tween a pyometra and a pregnant uterus efforts should

be madę to find floating segment* of the amniotic membranę or other fetal structures such as the umbilical cord or parts of the fetus itself.

The ultrasonic diagnoses of muco- and urometra are based on similar criteria as are used for a pyometra, Mucometra is occasionally diagnosed in mares with an imperforate hymen. Most commonly the diagnosis is madę in young fillies. After the onset of ovarian and uterine cyclic activity during puberty, the usual outflow of secretions from the genital tract is prevented by the persistent hymen. This then leads to the aceumulation of the mucous secretions in the vagina and uterus. Apart from typical clinical signs, such as the protrusion of the hymen from the vulva or the rectally palpable en-largement of the uterus, the retained fluid can also be demonstrated sonographically in several sections of the uterus (Fig. 1.111).

Anatomical changes of the genitalia, such as the cranioventral displacement of vagina and uterus in the presence of an open cervix, can cause urine to flow cranially into the uterus and establish a urometra. Ultrasonically such a uterus appears fluid-filled and widely dilated (Fig. 1.112). The characteristic echogen-icity of eąuine urine often also leads to floccular reflections in the uterine contents as in cases of urometra.