CLINICAL EVALUATION OF MARES

HISTORY-

As a rule, there is less recorded history available about mares than cows, and the information which might be obtained is less complete. If possible, information should be acquired with regard to the following:
 Age of the animal
 Duration of the present ownership
 Previous pregnancies and foalings, if any
 Date of the last foaling and the rate of growth and development of the foal
 History of any infections
 The month of commencement of the breeding season as well as its length
 Intensity of estrus, the length of the estrus period and the length and regularity of the estrous cycle
 The client should be asked about the method employed for observing heat 

CLINICAL EVALUATION OF MARES

PHYSICAL EXAMINATION

Visual Examination -
 Conditions that alter the general conformation and the external appearance of the cow are simply not encountered in the mare.
Changes in the appearance of the “tailhead” are not as apparent in the mare.
 Relaxation of the pelvic diaphragm and vulva associated with gestation is observed during the last 2 to 5 days of pregnancy, and then not in all animals.
 Copious discharge of estrus mucus is seldom observed in the mare. Thus, information suggesting physiological events cannot be obtained by visual inspection.
 Significant information, however, is gained from observing conformation changes involving

External genital organs
Abnormal vaginal discharge
Hoof and leg infirmities such as a rotated third phalanx following acute laminitis that may make a mare reluctant to stand for breeding or may make her unfit to carry a pregnancy to term
Pelvic injuries or abnormalities that may predispose a mare to dystocia 
Small stature
Hirsutism associated with a pituitary tumor may be the cause of a mare’s unseasonal anestrus  Hypertrophic pulmonary osteopathy has been associated with certain types of ovarian tumors in mares

Examination of Genitalia-
 After completing the general physical examination, a detailed evaluation of the reproductive organs should be undertaken with the tail wrapped in gauze and tied out of the way
 Mammary glands should be examined and palpated for signs of mastitis, abscessation, neoplasia or injury.
 Vulva should be examined for conformation, apposition, tone and evidence of discharges. 

 Mal apposition of the vulvar lips or poor vulvar conformation may lead to pneumovagina and fecal contamination of the vaginal vault  
Examination of the vulvar area should continue with the examination of the clitoral fossa and clitoris that harbors the contagious equine metritis organism Hemophilus equigenitalis.

 The examination then continues with either rectal or vaginal palpation.

Pneumovagina-
 Pneumovagina or” windsucker” condition is the most frequent conformation change observed in mares.
 In normal mares the long axis of the vulva occupies an almost vertical position. In pneumovagina it forms an acute angle with the horizontal plane. In extreme cases the vulva might be found in an almost horizontal position
 The vulvar lips are relaxed, resulting in partial exposure of the vestibulum and clitoris. Scar tissue and consequent deformation of the vulva lips are frequently observed in mares which have experienced dystocia and lacerations
 The anus is sunken and enhances the appearance of a more or less horizontally directed vulva. The relaxed vulva and its position facilitate contamination of the vagina with fecal material
 The relaxation permits aspiration of air into the vagina and also into the uterus, especially during estrus thus allowing saprophytic and pathogenic bacteria to gain entrance into the genital tract. Treatment should be directed at correcting the cause of pneumovagina, and concurrently treating the resulting acute endometritis. The former can be done surgically by Caslick’s operation.
 Almost all animals with pneumovagina are infertile and show signs of genital infection 

Rectovaginal Fistula -

 The trauma which results in rectovaginal fistula affects the perineum, vulva, vestibule and rectum. Localized internal fistulas are rare.
 The lesions are easy to see, and the diagnosis of either type of fistula does not present any difficulties. This abnormality leads to contamination and consequent infection of the genital tract.

 Abnormal Development of the Vulva-
 The vulva might be too small when compared with general body size
 Asymmetry of the vulva and overlapping of vulvar lips are abnormalities that result in improper closure of the vestibule and permit aspiration of air Discharge from the Vulva
 During estrus the vulva is moist, but the copious discharge which is a sign of estrus in the cow is not present
 The very viscid discharge present in practically all cows in advanced pregnancies is absent in the mare
 Lochia, the grayish red discharge in the postparturient animal, appears in much lesser amounts and only for a few days in the postparturient mare.

 Postestrual hemorrhage is not seen in the mare. The appearance of an abnormal discharge is, however, significant
 Abnormal discharges include haemorrhagic and purulent discharge.

Haemorrhagic discharge-

 Bloody discharge from the vulva is always serious. In the recently serviced mare, it indicates service injuries
 Bloody discharge from a pregnant animal practically always indicates threatened or completed abortion 

Purulent discharge-

 Purulent material in the vaginal discharge may be observed directly, or noticed as crusts on the thighs and a loss of hair between the thighs if the exudates has been discharging for a longer period of time.
 Indicates the presence of inflammation in the genital or in the urinary tract, especially in the bladder.  Determination of the site of inflammation requires performing a vaginal examination and occasionally doing a rectal examination and urine analysis.

VAGINAL EXAMINATION -
 The vaginal speculum or vaginoscope is more frequently used for vaginal examination in the mare than in the cow and is always indicated whenever an abnormal discharge has been observed.

Preparation -
 Vulva and perineum are thoroughly cleaned
 The tail is wrapped and tied out of the way
 The area is disinfected using a mild surgical scrub
 Caution is taken to prevent forcing fluid through the vulvar cleft into the vagina Examination
 After drying the area the vulvar lips are separated and a sterile vaginal speculum, either tubular or the three-pronged Caslick speculum, is introduced into the vestibular area
 With the aid of a light, the speculum is used to examine o the cervical os for color and tone as soon as possible, since changes occur as cool air enters through the speculum. 
the vaginal wall for color, evidence of congestion or inflammation, tumors, lacerations and scars 
the vaginal floor for evidence of exudates or fluid accumulation or injury 
the dorsum of the vagina for evidence of injury or fistulation into the rectum.
 Endometrial cultures can be obtained during speculum examination  

Estrous cycle-
Diestrum
In the luteal phase vaginal mucosa is pale pink and rather dry. 
Speculum examination results in influx of air and ballooning of the vagina thus favouring visibility. However, exposure to air causes the mucosa to become congested and hence, the color of the mucosa should be noted immediately after insertion of the speculum. 
Secretion is absent.

Estrum -

Vaginal mucosa appears deep pink and glistening with a small amount of clear secretion on the floor of the anterior vagina
The external os is relaxed and lies limp on the floor of the vagina but is, however, extremely sensitive to touch and responds quickly by becoming erect. 
The appearance of the cervix is greatly helpful in determining whether a mare is in estrus or not. 

The erect cervical os during the luteal phase has been described as a “rosebud,” whereas the relaxed external os during estrus has been described as “wilted rose.” 

Pregnancy-

The vaginal mucosa appears dull, anemic, rough and extremely dry, and insertion of the speculum might be difficult.
The external os is more or less relaxed and covered with a sticky, grayish secretion.
 The stickly mucus sticks to the vaginoscope and to the vaginal mucosa and resembles rubbery glue during manual examination of the vagina.
 These findings are encountered in diestrus mares also

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