The Latest Research on Equine Placentitis - EquiManagement on Audio

0:00All the articles you have come to love in Equamanagement Magazine are now available on the Equamanagement on Audio podcast. Each article is released as its own separate episode to make them quick and easy to listen to. Just search Equamanagement on Audio on your favorite podcast player to listen to all the latest articles. Research Spotlight on Equine Placentitis The latest advice when it comes to diagnosing and managing this challenging cause of pregnancy loss in horses. Equine Placentitis is one of the most common causes of late-term pregnancy loss in horses, contributing to 20% to 30% of pregnancy losses worldwide. Placentitis can take one of three forms, ascending from bacterial or fungal contamination. Diffuse or multifocal Placentitis from hematogenous spread of infection elsewhere in the body. Nocardiophorm Placentitis identified in Kentucky.

1:03It's sometimes associated with amy colotopsis and or crossyella equi infection, but the cause remains poorly understood. The most commonly diagnosed form is ascending Placentitis due to bacterial contamination of the caudal reproductive tract. Infection ascends into the vagina and cervix and into the Corio-Alentoyus to adversely affect the fetus. One of the issues with ascending Placentitis is veterinarians typically don't identify it until late in the disease process. At that point, the mare might prematurely develop mammary enlargement and or lactation. On rare occasions, she might have a purulent discharge from the vagina that goes unrecognized as tail hairs sweep it up. Routine blood work is frequently unremarkable because the infection is localized to the fetal tissues. Diagnosing and treating ascending Placentitis

2:03At the 2025 VMX meeting in Orlando, Dr. Theresa Beechler of Iowa State University presented on causes, diagnosis and treatment of ascending Placentitis. Mares with poor perineal confirmation are most at risk. A careful examination might reveal that the vulva is tilted more than 20 degrees from vertical and or the vulvar lips do not oppose well. These mares are at risk of fecal contamination of the perineal area into the vaginal vault. Preventive techniques to counter poor perineal confirmation include a caslic's vulva plastic or a GADS procedure for refractory cases. Poor perineal confirmation might cause a mare to winch suck, which veterinarians can confirm by parting the vulvar lips to see if air aspirates into the vagina. Abnormal vulvar position can lead to urine pooling or fecal contamination of the caudal reproductive tract. Other internal problems might include a poor vestibulovaginal seal between the vagina and the vestibule or cervical incompetence.

3:11Common bacteria to invade the reproductive tract include streptococcus-equi-subspecies-zoa-epidemicus, ecoli, clubcella pneumoniae and pseudomonas. These bacteria can colonize and replicate in the allantoic cavity and umbilicus, and the fetus might swallow or inhale amniotic fluid. With infection, the fetus develops sepsis. A subsequent rise in inflammatory cytokines and prostaglandins increases the mare's uterine contractility while modifying the hormonal profile and activating the hypothalamus pituitary adrenal axis. As the fetus becomes compromised, a preterm rise or rapid decline in progestins and reduced estrogen levels can develop. A mare with a normal pregnancy should have estrogen levels over 500 mg per milliliter. At this point in the process, an abortion or the premature delivery of a severely compromised and sick foal will occur.

4:14Beechler reported that with placentitis, everything starts at the cervix. Following abortion or birth, the placenta will be a demidus, thick, and necrotic at the area of the cervical star. In cases of suspect placentitis, veterinarians can use transrectal ultrasound to measure the combined thickness of the uterine endometrium and placenta. Normal CTUP measurements are as follows. Days 271 to 300 should be less than 7 mm. Days 301 to 330 should be less than 10 mm. Past day 330 should be less than 12 mm. The cervix should not have defects visible on ultrasound and should be a solid structure with fine striations without any surrounding air or mucus. Another parameter for assessing fetal well-being is the fetal heart rate obtainable via trans-abdominal ultrasound. Because the process of rectal palpation and diagnostic ultrasound are stimulatory, the fetus is usually active with a corresponding heart rate.

5:22In addition, color Doppler can help determine fetal viability by measuring blood flow in the fetal vessels and umbilical cord. Research is underway to identify early biomarkers, because once changes are evident on transrectal ultrasound, the mare is far along in the disease process. Potential biomarkers include a severe increase in the progesterone metabolite, 20 alpha DHP, as well as a low ratio of comprehensive hormone panel to 20 alpha DHP. Serum amyloid A, lactate, haptoglobin, and alpha-fetoprotein are also being evaluated. Researchers are investigating metabolomics and proteomics for gene alterations, transcription and protein expression and metabolism. Another biomarker, EIL-1 beta, can also be significantly elevated with compromised folds, but it might not be specific for placentitis. Beechler urged vets to follow the three pillars of treatment, antimicrobials, anti-inflammatories, and topolytics such as ultranagest, at least until the mare delivers.

6:33Antimicrobial drugs. Ideally, first obtain culture and sensitivity from vaginal or cervical discharge. Antimicrobials include. Systemic trimethyprim sulfamethoxysol, TMS, and-or procan penicillin G, PPG, plus gentamycin, pen-gen. TMS is only effective in about 49% of cases. Doxycycline might have a role. Ceptiafure achieves insufficient concentration in allantoic fluids. Local antibiotics with trans-servical administration of pen-gen. In one study of intrauterine PPG plus gentamycin, given between days 280 and 295 of gestation in normal mayors, all fold without complications 12 to 58 days after the antibiotic infusion. The combination antibiotic was administered at a mean gestational age of 322.7.

7:34Intrauterine infusion during pregnancy meets further study for safety and efficacy. Anti-inflammatory medications. Anti-inflammatories to down-regulate the inflammatory cascade and block the production of cytokines and prostaglandins include. Flunixin meglamine. Phyrocoxib. Aspirin might help improve uterine blood flow, act as an anti-platelet drug, and inhibit COX-1 and 2 to some degree. Pentoxophylline. Dexamethazone. Estradiolcipionate to help with placental blood flow. Preventing abortion in affected mayors. At a 2025 Gluck Center equine veterinary seminar in Kentucky, Dr. Hosam L. Shake Ali, of the Martin Gatton College of Agriculture, Food and Environment, said studies have shown that just 1 million bacteria are enough to induce placentitis. All efforts to prevent contamination of the caudal reproductive tract should be taken prior to breeding.

8:39Ali suggested methods to encourage myometrial quiescence and help mitigate abortion in mayors with placentitis. The sides altrenogest, he said isoxoprene or clenbutyrol, have been considered for their effects on relaxing smooth muscle. However, he reported a lack of evidence to support using them to treat placentitis. Studies suggest selective COX-2 inhibitors like phyrocoxib could slow myometrial activation. Also, an antagonist in humans is being investigated in horses for its toll-like receptor-4 inhibition of inflammation from lipopolysaccharide-induced preterm uterine contractility. Amatryptoline is both a receptor-2 and-4 antagonist. Ali said uterine quiescence depends on progestin availability, which inflammation alters. However, he noted that progestin supplementation might not be effective for treating placentitis because the condition is associated with functional withdrawal of progestins in the myometrium.

9:44He suggested a combination of treatments based on favorable study results. Altrenogest and phyrocoxib suppress inflammatory cytokines and prostaglandins in amniotic fluid and improve full survival in mayors with placentitis.