Page 441 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

416 CHAPTER 2

VetBooks.ir 2.16 Rectal examination
This is a routine procedure in equine stud farm
veterinary work and is used to palpate the cervix,
uterus and ovaries both pre-insemination and dur-
ing pregnancy. It also facilitates transrectal ultra-
sonographic examination of the tract, which has
become so important in the last 20 years. There are
significant risks involved in the procedure, both to
the mare (rectal tears) and to the people carrying
out the technique. Adequate restraint is therefore
essential and the use of stocks preferable. Nervous
animals may require sedation or the application of
a lip twitch. A careful systematic technique, using
Fig. 2.16 A sterile vaginal speculum has been inserted
and a sterile swab is pushed up inside the speculum copious obstetric lubricant, is important. The nature
to take a sample for culture and/or cytology from the of the cervix and uterine tone should be assessed.
cervix and uterus. (Photo courtesy Graham Munroe) The size, shape and position of the uterus are impor-
tant components of manual pregnancy diagnosis and
BSE. Careful palpation and ultrasound examination
2.17 of the ovaries for follicles, CH or CL are central to
stud farm management.

Ultrasonographic examination
This technique, introduced over 30 years ago, has
revolutionised the veterinary input into equine stud
medicine. Ultrasound waves of the type commonly
used are not hazardous and ultrasonographic exami-
nation of the reproductive tract increases the quality
and accuracy of information. Transrectal ultraso-
nography is usually carried out with a 5 or 7.5 MHz
linear array probe and allows visualisation of ovar-
ian structures (size, CL, follicles, neoplasm); uterine
size, free fluid or air, oedema/folds, cysts, neoplasia,
pregnancy from day 11 or 12; and cervical and vagi-
Fig. 2.17 A view, after opening the vulva and vagina nal abnormalities. A careful systematic examination
with a speculum, of a ventral vestibular mass, which of the entire tract is essential and careful recording,
on removal was found to be benign. (Photo courtesy including using image-capture software or photo-
Graham Munroe) graphs, is essential.
Transabdominal ultrasonography to evaluate fetal
viability and placental health is best performed using
to dilate the cervix manually, sometimes enough to a linear array transducer of 2.5–3 MHz.
allow palpation of the uterine lumen. Care should
always be taken to ensure that the mare is not preg- Uterine swab for culture
nant before dilating the cervix or introducing any This is very useful for evaluating the breeding
instrument through it, because to do so in a preg- mare, but in recent years the significance of bacte-
nant mare will cause abortion. An endometrial rial cultures from this source has undergone some
biopsy punch and fibreoptic instrument can also be discussion. Cultures from the uterus are possible
introduced in a similar way. using a number of different techniques via either a