title: B-mode and Doppler ultrasonography in pony mares with experimentally induced ascending placentitis.
abstract: BACKGROUND
  Early, accurate diagnosis of ascending placentitis in mares remains a key challenge for successful treatment of the disease. Doppler ultrasonography has shown promise as a tool to diagnose pregnancy abnormalities and is becoming more available to equine clinicians. However, to date, no studies have prospectively compared this technique to standard B-mode measurement of the combined thickness of the uterus and placenta (CTUP).
  
  
  OBJECTIVE
  The objective of the current study was to compare Doppler and B-mode ultrasonography for the detection of experimentally-induced ascending placentitis in mares.
  
  
  METHODS
  Eleven healthy pony mares in late gestation were used in this study. Placentitis was induced in 6 mares between Days 280 and 295, while 5 mares served as negative controls. All mares were intensively monitored until delivery. Fetal heart rate, CTUP, uterine artery blood flow (resistance index, pulsatility index, arterial diameter and total arterial blood flow) and physical examination findings were recorded at each examination. Mares with an increased CTUP above published values were treated in accordance with published recommendations. Foals and fetal membranes were examined at birth. Ultrasonographic parameters were compared between groups using ANOVA. Foal viability and histological presence of placentitis were compared using a Fisher's exact test.
  
  
  RESULTS
  The CTUP was increased above normal in 5 of 6 inoculated mares within 3 days after inoculation (P = 0.05). The sixth inoculated mare was excluded from subsequent data analysis. Uterine artery blood flow, physical examination findings and fetal heart rate were not different between groups. Gradual increases in CTUP, arterial diameter and total arterial blood flow were detected with increasing gestational age in the control mares (P = 0.02, P = 0.00001 and P = 0.00001, respectively).
  
  
  CONCLUSIONS
  The CTUP, but not uterine blood flow, was different between groups (P = 0.00001). Recorded CTUP values for control pony mares were similar to previously published values for light breed horses.
authors: College of Veterinary Medicine, North Carolina State University, North Carolina, USA. scott_bailey@ncsu.edu
authors: C S
authors: CS
authors: Bailey
authors: J M
authors: JM
authors: Heitzman
authors: C N
authors: CN
authors: Buchanan
authors: C A
authors: CA
authors: Bare
authors: R B
authors: RB
authors: Sper
authors: L B
authors: LB
authors: Borst
authors: M
authors: M
authors: Macpherson
authors: K
authors: K
authors: Archibald
authors: M
authors: M
authors: Whitacre
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005260:Female; D006734:Horse Diseases / Q000000981:diagnostic imaging* / Q000382:microbiology / Q000473:pathology; D006736:Horses; D010922:Placenta Diseases / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D050497:Stillbirth; D013290:Streptococcal Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D018502:Streptococcus equi; D018608:Ultrasonography, Doppler / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*