Go­ing un­der to­gether

When a mare de­vel­ops colic late in her preg­nancy, surgery could put her life, as well as the life of her foal, at risk.

EQUUS - - Eq Casereport - By Chris­tine Barakat

It’s not un­usual for a preg­nant mare to lie down in her stall, but Kim Sch­midt knew her mare Susie well enough to re­al­ize some­thing was amiss. Susie was due to de­liver her foal in less than a week’s time but Sch­midt could tell that her mare’s be­hav­ior in­di­cated some­thing other than la­bor.

“I bred her, raised her and trained her my­self,” says Sch­midt, a dres­sage rider, trainer and judge based at her cen­tral Vir­ginia fa­cil­ity, Grayson Farm. Un­der her regis­tered name, O’Su­san­nah, Susie had ex­celled at three-day event­ing and dres­sage, and she had ex­pe­ri­ence as a brood­mare. “I’d helped her de­liver two foals be­fore, so I had a pretty good idea of what was nor­mal for her, and this wasn’t it.”

Susie would lie down and stretch out flat, then get up only to lie down and stretch out again. “She wasn’t pac­ing or sweat­ing or look­ing anx­ious like a mare would in la­bor,” says Sch­midt. “But she wasn’t rolling or look­ing at her sides like a horse with full-blown colic will. She was just stretched out flat and look­ing un­com­fort­able. She also wasn’t pick­ing through her hay like I’d ex­pect her to be do­ing. It was sub­tle, but I knew some­thing wasn’t right.”

Sch­midt called Keswick Equine Clinic in Gor­donsville, Vir­ginia, and after dis­cussing Susie’s signs with the on-call vet­eri­nar­ian, was in­structed to give the mare a dose of Banamine0 and mon­i­tor her very closely. “I was told that if Banamine took away the signs, it was prob­a­bly colic,” says Sch­midt. A la­bor and de­liv­ery nurse her­self, Sch­midt was com­fort­able ad­min­is­ter­ing the drug, and af­ter­ward she kept an eye on her mare.

“The Banamine took the signs away com­pletely,” says Sch­midt. “She was up and eat­ing and look­ing com­fort­able within 20 min­utes.” After call­ing the clinic back with this up­date, Sch­midt was ad­vised to con­tinue watch­ing the mare and call again if the colic signs came back. They did, and soon Re­becca Kramer, DVM, from Keswick was on her way to the farm.

When Kramer ar­rived, she found Susie ly­ing ster­nally in her stall. She gave the mare a full exam and found signs of mild dis­com­fort, in­clud­ing an el­e­vated heart rate of 56 beats per minute. Kramer needed to de­ter­mine if the pain was com­ing from colic or dys­to­cia, a dif­fi­cult de­liv­ery. She per­formed a rec­tal exam on the mare and con­cluded that the foal was not po­si­tioned as if Susie were in la­bor. The foal filled the en­tire left half of the ab­domen, and Kramer felt a large pocket of gas on the right side, which con­cerned her. Kramer used a na­so­gas­tric tube to check for re­flux, the mix of ac­cu­mu­lated feed, wa­ter and gas­tric juices that can in­di­cate a horse’s stom­ach is not emp­ty­ing. Find­ing no re­flux, Kramer used the tube to de­liver wa­ter, min­eral oil and elec­trolytes to Susie, a com­bi­na­tion that would keep her hy­drated and en­cour­age her gut to func­tion nor­mally. By the time Kramer left, Susie was hap­pily eat­ing hay. She left Sch­midt with

in­struc­tions to watch the mare closely through­out the night and call if she showed signs of dis­com­fort.

Susie con­tin­ued to be in­ter­mit­tently un­com­fort­able, so when morn­ing ar­rived so did Mark Fo­ley, DVM, also from Keswick. He gave her another thor­ough exam and, based on her con­tin­ued dis­com­fort and lack of ma­nure pro­duc­tion, de­ter­mined that she ei­ther had an im­paction or dis­place­ment of her large colon. He made a call to Blue Ridge Equine Clinic in nearby Earlysvill­e and ar­ranged for a re­fer­ral to the clinic for a more ex­ten­sive workup and treat­ment.

“I loaded her up im­me­di­ately and headed out,” says Sch­midt.

An in­testi­nal im­passe

Susie re­ceived a full ex­am­i­na­tion from Paul Stephens, DVM, ACVS, when she ar­rived at Blue Ridge late Fri­day af­ter­noon. “At this point, we were in­creas­ingly con­cerned that rather than a sim­ple im­paction, we were deal­ing with some­thing more com­pli­cated,” he says. “I told Kim we’d give it another 12 hours in case it was just an im­paction that might move, but if things didn’t im­prove, surgery might be our only op­tion.”

It was still un­clear what was caus­ing Susie’s colic, but her case and con­di­tion had al­ready re­vealed sev­eral clues. An im­paction of feed or hay in the in­testines would likely have al­ready been moved by the large amounts of fluid and oil she had been given. A twist in the colon (tor­sion) would be caus­ing acute pain, but Susie still seemed only mildly un­com­fort­able. “Con­sid­er­ing all of this, our num­ber one dif­fer­en­tial di­ag­no­sis was a dis­place­ment of the colon of some type, where a change in po­si­tion of the or­gan causes it to be­come blocked off,” says Stephens.

An ul­tra­sound0 ex­am­i­na­tion the fol­low­ing morn­ing pro­vided one last im­por­tant clue to the spe­cific type of dis­place­ment Susie had. “In a left dor­sal dis­place­ment, the colon moves up be­tween the spleen and body wall on the left side. There is a notch where the colon can drop down and be­come caught,” ex­plains Stephens. “On an ul­tra­sound in those cases, you’ll see only gas above the spleen, not the kid­ney like you should.” Susie’s ul­tra­sound re­vealed both the spleen and kid­ney, sug­gest­ing her dis­place­ment was a right dor­sal dis­place­ment, where the colon folds back on it­self, like a kink in a gar­den hose.

“Dis­place­ments aren’t as bad as twists,” says Stephens, “be­cause the blood sup­ply in the in­testines isn’t cut off. You won’t have the hor­ri­ble pain and death of the or­gan, and there’s not as much ur­gency to cor­rect the prob­lem be­fore more dam­age is done.”

Defini­tively di­ag­nos­ing right dor­sal dis­place­ments re­quires surgery, and if Susie hadn’t been in foal, she would have been headed to the op­er­at­ing room. But, says Stephens, “you never want to put a preg­nant mare through surgery if you can avoid it, par­tic­u­larly one as far along as she was.” On the other hand, Susie had gone with­out food for nearly 48 hours, mean­ing her foal was also be­ing de­prived of nu­tri­tion. The mul­ti­ple doses of med­i­ca­tions could also be ad­versely af­fect­ing the foal, along with the gen­er­al­ized stress Susie’s body was un­der. It was a dif­fi­cult judg­ment call, but one that had to be made.

“I told Kim we’d give it one more night to see any im­prove­ment,” say Stephens. More flu­ids and painkiller­s brought no changes, and early Sun­day morn­ing Susie was prepped and headed into surgery.

“I re­mem­ber Dr. Stephens telling me that if it comes down to sav­ing ei­ther the mare or the foal, he chooses the mare,” says Sch­midt. “He wanted to know if I agreed with that. I told him I’d love to have both, but if he could only save one, to make it Susie.”

Ta­ble for two

Per­form­ing surgery on a heav­ily preg­nant mare puts both the mare and foal at risk, says Stephens:

“There are a cou­ple of ar­eas of con­cern. First of all is anes­the­sia for the mare. When you place her on her back, the foal presses into her di­aphragm, so it be­comes very hard to keep her ven­ti­lated and breath­ing prop­erly. There’s also con­cern about her blood pres­sure be­cause the foal presses down on her cau­dal vena cava, which re­turns blood to the heart. If her blood pres­sure drops, so will the foal’s, but there’s no way to even mon­i­tor that. Then you have wor­ries about re­cov­ery. When a mare is that size, she can have trou­ble get­ting back to her feet, and the risk of a trau­matic in­jury, like frac­tur­ing a leg, in­creases.

Th­ese are just a few of the rea­sons we are loath to put a mare on the ta­ble that late in a preg­nancy.”

If Susie were a woman, her physi­cian might choose to de­liver the baby via cesarean sec­tion be­fore per­form­ing any other nec­es­sary surgery. That, how­ever, isn’t an op­tion in equine vet­eri­nary medicine. “Foals need ev­ery sin­gle day of ges­ta­tion they can get,” says Stephens. “Ce­sare­ans are oc­ca­sion­ally done in horses, but only after the mare has gone into la­bor on her own. Any ear­lier and the sur­vival rate is not good at all. De­liv­er­ing a foal even a week early by cesarean sec­tion would be ex­tremely risky.” Fur­ther­more, the ad­di­tional time in surgery a cesarean sec­tion would re­quire would also put Susie’s life at risk. “There’s ad­di­tional stress, blood loss and a risk of con­tam­i­na­tion,” says Stephens.

The only op­tion would be to sur­gi­cally cor­rect the colic and then close Susie up and let her de­liver on her own.

As soon as the sur­gi­cal team had opened Susie’s ab­domen, it was clear to Stephens that a right dor­sal dis­place­ment was the cause of her colic. “It was what we had an­tic­i­pated and were pre­pared to fix, so that was some­what re­as­sur­ing,” he says.

The first step was to pull the mare’s colon up and out of her ab­domen, then lay it out on a tray next to the sur­gi­cal ta­ble. “In th­ese cases the colon is ex­tremely heavy and packed with backedup feed,” says Stephens. “It’s a del­i­cate pro­ce­dure be­cause it’s easy to tear the in­testines, cre­at­ing a very bad sit­u­a­tion.” With the colon pulled out and ac­ces­si­ble, Stephens made a small in­ci­sion and care­fully mas­saged out the packed feed­stuff, flush­ing the space with a large amount of wa­ter as he worked.

Once the colon was empty, Stephens could be­gin to de-ro­tate it back into its nor­mal po­si­tion. That process, how­ever, was greatly com­pli­cated by the large fe­tus ly­ing di­rectly on top of the cru­cial area. “You have very, very limited space to work within, and you can’t see any­thing,” he says. “Es­sen­tially, I had my arms down in this deep, dark hole of her ab­domen, work­ing by feel alone. It was ex­tremely tech­ni­cally chal­leng­ing---one of the most dif­fi­cult dis­place­ments I’ve had to cor­rect.”

With that done, Stephens su­tured the 10-inch in­ci­sion, and Susie was put in a snug belly­band to help pro­tect the in­ci­sion site from trauma or con­tam­i­na­tion. A typ­i­cal colic pa­tient would wear the belly­band for only a few days, but Stephens ad­vised Sch­midt to leave it on Susie un­til she had de­liv­ered her foal be­cause it could po­ten­tially pro­vide ad­di­tional support to the in­ci­sion.

Per­form­ing surgery on a heav­ily preg­nant mare puts both mother

and foal at risk.

SUP­PORT­IVE CARE: In­tra­venous flu­ids kept Susie hy­drated as vet­eri­nar­i­ans worked to un­cover the cause of her colic.

SONNY BOY: With surgery and a dif­fi­cult birth be­hind them, Susie and Dino are happy and healthy.

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