A displaced ovary, and the pain from ovarian dysfunction can be addressed through osteopathic treatments to the autonomic nervous and cranio-sacral systems.

Osteopathy is a manual therapy that helps horses maintain health despite the unnatural demands placed on them by people. It is based on a precise knowledge of the structural and functional anatomy of bones, muscles, the circulatory system, and especially the nervous system. Osteopathic manipulation stimulates the body so that the musculoskeletal system, behavior and all other systems are optimized.

A.T. Still, who pioneered the modality in the 1800s, stated that in osteopathy “the cause of disease is considered chiefly from one standpoint, viz.: disease is the result of anatomical abnormalities followed by physiological discord.”¹ In modern days, Janek Vluggen of the Vluggen Institute for Equine Osteopathy and Education, has used his expertise in visceral osteopathic principals, which relate to the autonomic nervous system and cranio-sacral system, to deepen the healing potential of osteopathy.

“Hard to reach” ovaries

We have all experienced the mare with “hard to reach” ovaries. At first, Dr. Waldron thought this was just a variation from the normal, and prayed nightly for longer arms. It wasn’t until she started studying osteopathy that she discovered not only the cause of these high, tight ovaries, and how to correct them, but also an incredible way to change mare behavior.

Over the last few decades, many authors have related ovarian dysfunction to personality problems in the equine. Ovarian tumors, cysts and granulomas were thought to contribute to hypersensitivity and aggression. After these issues were corrected, behavior improved as cycling normalized, so the behaviors were thought to be merely hormone-related.^2,3,4,5 Chronic pain is now being considered as part of the issue.^6,7 In 2010, a French researcher, Fureix, described an experiment which proved that chronic back pain could cause increased aggression or violent behavior.⁷

As veterinarians, we have worked with mares who have a “grumpy” disposition that often seems present or accentuated during their heat. Most of these mares have sensitive ovaries during this phase of their cycles, and a significant number have “out of reach” ovaries. These mares are difficult to palpate due to sensitivity, and in general seem irritable and high strung. In the “out of reach” ovary, the mesovarium has wrapped around the ovary and pulled it forward and dorsally. Pain is caused by pressure from the mesovarium. The abnormal location and pain can be further explained by the functionality of the autonomic nervous system.

According to Mayhew⁶, visceral pain may be transmitted through free nerve endings in the organ wall. Though the sympathetic and parasympathetic systems are efferent systems, they share pathways that are also used by the afferent pain sensors. Increased sympathetic or parasympathetic influence can change the base activity of the segments they supply. Increased sensitivity of the spinal nerves, and sympathetic and parasympathetic pathways going to the ovary, alter the ovary’s mobility and its ability to slide within its fascia. The ovary and associated ligaments become very sensitive to pressure and overstretching. The pain this causes will continue for a lifetime unless we, as veterinarians, address the situation.

Osteopathic palpation of uterus and ovaries

The ovary is held in position by the mesovarium and the suspensory ligament. In the normal mare, these ligaments are soft and stretchy, and the ovary is mobile in our fingers so we can determine the presence of follicles, CLs and CHs.

An osteopathic exam consistent with immobility in the ovary shows immobility in the lumbar vertebrae L1 to L3, possibly T17 and T18, and in the sacrum and poll. Tension and sensitivity are seen in the flank inner thigh and stifle areas, and possibly in the perineal area, with contraction of the psoas and abdominal muscles.

On rectal exam, one ovary is pulled forward and usually held tight up against the body wall. The information provided by this ovary, in pre-ultrasound days, was available to our fingertips only, but was just out of normal reach. At this point, the problem ovary is actually wrapped in the mesovarium and is unable to swing like a normal ovary. The goal is to unwrap this ovary and let it drop freely into the pelvic room and regain its lost softness and stretchability, allowing palpation similar to the other ovary.

The following series of pictures⁸ demonstrates normal osteopathic palpation of the uterus and ovaries, so the veterinarian is able to recognize any immobility, adhesions, abnormal feel or location.

Steps to Palpating the Equine Female Urogenital Tract

1. Move cervix lateral left and right: mobilization of restrictions in ligament, latum and parametrium.

As you enter the rectum, begin to palpate ventrally for the cervix. Once you find it, place the flat of your hand lateral to the cervix and attempt to move the cervix across midline until you reach resistance. Repeat on the other side. Each side should have an equal range of motion. If not, first use gentle pressure to move the side with greater mobility to the full extent of its motion. Then move the opposite side through its resistance to an equal range of motion.

2. Move corpus to the right and left: mobilization of mesometrium and broad ligament.

Continue this same technique up the body of the uterus, using your flattened hand on the outside of the uterus to push towards and across midline. The corrections are also the same.

3. Lift bifurcation: test and mobilixation of the uterine body.

When you reach the bifurcation, scoop under the uterus and lift it dorsally off the bladder; release the uterus and scoop under the cranial aspect of the bladder, lifting the ventral side of the bladder dorsally and away from the pubic bone. Next, move your hand to the right cranial edge of the bladder and lift it caudo-dorsally and towards midline. Move your hand to the left cranial edge and lift it caudo-dorsally and towards midline.

4. Move uterine horn in longitudinal direction and around its own axis: mobilization mesometrium and teres ligament.

Come back to the base of the uterine horns, scoop one side up and grasp in your hand. You will be doing two motions at once. Hold the uterus in your hand and use your arm to move the uterus cranial, ventral and slightly towards midline. Simultaneously bend your wrist so your fingers point towards the inside of your forearm and roll the uterine horn cranio-ventral. Continue this technique all the way up the tip of the horn.

5. Stretch the suspensory ligament of the ovary

When it comes to the ovaries, start by holding an ovary in the palm of your hand. Use your most cranial fingers to stroke or stretch the suspensory ligament of the ovary. Start with a light touch – this is where mares are most sensitive. Stretch the suspensory ligament and move the ovary caudo-ventral and to midline. Some variation in this motion occurs with decreased mobility in the ovaries. The ovary should be mobile enough to move with little to no resistance to an area on midline at the level of the body of the uterus, or even the bladder, just cranial to these structures. You also rotate the ovary while making this motion. Start with your palm facing the lateral wall of the abdomen (flank) and end with your palm up and knuckles down.

Then lift the ovary dorsally by bending your wrist. Move from a knuckles-down palm-up position to a knuckles-up palm-down position and raise the ovary. Then once again rotate the ovary cranially and caudally 180° in your hand (half a turn of a doorknob each way). Once you have mobilized the ovary to this position, rotate it cranially and caudally 180° in your hand, like turning a doorknob half a turn each way.

6. Rotate ovary to exorotation.

Repeat the palpation of the uterine horn and ovary on the opposite side and mobilize any restrictions until the uterus and ovary are free.

In Summary

Visceral pain is transmitted through free nerve endings in the wall of the ovary, via the sensory neurons that use the same pathway as the sympathetic and parasympathetic systems. Although the sympathetic and parasympathetic systems are efferent systems, they share pathways with afferent pain sensors and can influence each other. When this base activity increases, both the ovary and ligaments become sensitive to a change in position and overstretching, and may also have decreased mobility.

This problem can be diagnosed through immobility of the first three lumbar vertebrae, along with immobility in the sacrum and poll. This loss of mobility at the level of the spinal lumbar nerve results in irritation and hypertonicity of the tissues supplied by the nerves leaving the spinal canal at these restricted points. This can influence not only the ovaries, but also the uterus, bladder and ureters, and consequently cause behavior issues.

Careful osteopathic diagnosis and ovary palpation during colic and reproductive exams can help a large number of mares live a normal and more comfortable life.

Illustrations courtesy of Janek Vluggen, DO, MRO, EDO and the Vluggen Institute for Equine Osteopathy and Education

References

¹ Still, A.T. Osteopathy Research and Practice, Journal Printing Company, Kirksville, MO, 1910, p. 15.

² Donna Judy E. Curtin. “Ovarian Hematoma In An 11-Year-Old Thoroughbred-Hanovarian Mare”. Can Vet J. 2003 July; 44(7): 589–591. PMCID: PMC349373.

³ Maurice KT. “Diagnosis And Surgical Removal Of A Granulosa-Theca Cell Tumor In A Mare”. Can Vet J. 2005 Jul; 46(7):644-6. Source Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1.

⁴ Smith LJ, Mair TS. “Unilateral And Bilateral Laparoscopic Ovariectomy Of Mares By Electrocautery”. Bell Equine Veterinary Clinic, Butchers Lane, Mereworth, Kent. Source ME18 5GS. PUBMED ID: 18776175.

⁵ Bosu WT, Van Camp SC, Miller RB, Owen RR. “Ovarian Disorders: Clinical And Morphological Observations In 30 Mares”. Can Vet J. 1982 Jan;23(1):6-14. PUBMED ID: 7066859.

⁶ Mayhew IG. Large Animal Neurology, 2nd Ed., Wiley-Blackwell, 2008.

⁷ Barral JP, Mercier P. Visceral Manipulation, Revised Edition, Eastland Press, Inc. 2005, p53-59.

⁸ Vluggen J. Classifications Of The Visceral Motions According The Origin Of Existence. AIEO, San Marcos, TX 2012.