Twin pregnancy in mares is one of the leading causes of abortions. Abortion invariably impacts both fetuses. This report describes an unusual case of a twin surviving to term following the abortion of its co-twin at 9 months in a 7-year-old Egyptian Arabian mare. At the time of abortion at 9 months of gestation, the size of the aborted fetus was equivalent to one of approximately 5 months of age while the age of the live co-twin was 9 months. Both fetuses were males. A skin sample was collected from the aborted fetus and hair samples were collected from the dam, sire and live foal for parentage analysis. The parentage analysis confirmed that both fetuses were by the same dam and sire stallion. The authors suggest several scenarios to explain this condition. This report describes a unique case of a twin surviving to term following the abortion of its co-twin at 9 months in a mare.

Accurate estimation of a horse\'s age based on the condition of the tooth status is necessary as a scientific and artistic technique, which has not been performed so far in pure Arabian horses of Khuzestan (southern west of Iran). This study aimed to investigate the age-dependent changes in the morphology and morphometry of the incisors in Arabian mares of Khuzestan to estimate age and to compare the estimated dental age and actual age. In this study, 78 Arabian mares of Khuzestan were examined in several equestrian clubs. Then, images were taken with a digital camera from the vestibular and occlusal surfaces of the lower incisors. Parameters of deciduous and permanent teeth eruption and their number, occlusal surface changes in the lower incisors including appearance and disappearance of the cup, enamel spot, dental star and appearance, and changes of Galvayne\'s groove in the upper corner incisor were investigated. Comparison of the clinical crown length of incisors in each group showed that first, second and third incisors (I1, I2, and I3) had the maximum to minimum crown length, respectively. The correlation between actual age and clinical crown length was strong in I1 (r = 0.73, p ≤ 0.001), I2 (r = 0.8, p ≤ 0.001), and I3 (r = 0.81, p ≤ 0.001) in the Arabian mares of Khuzestan. The correlation of estimated dental age with actual age in the Arabian mares of Khuzestan was very strong (r = 0.992, p ≤ 0.001). Therefore, the dental age estimation in the Arabian mares of Khuzestan appears to be very close to the actual age of the animal.

This study was designed to examine the effect of the intrauterine infusion of platelet-rich plasma (PRP) or equine lyophilized growth factor (L-GFequina) on the follicular growth, endometrial thickness, estrus cycle length, and pregnancy rate in purebred Arabian mares. A total of 73 purebred Arabian mares who experienced repeat breeding for three successive cycles were randomly divided into the following three groups: control group, without treatment; second Group (PRP group), in which mares were intrauterine infused with 20 mL of fresh PRP on the second day after the end of physic estrus phase; and the third group (L-GFequina Group), consisting of mares that were intrauterine infused with 20 mL of reconstituted lyophilized horse platelets growth factors (L-GFequina) on the second day after the estrus phase. The results showed no significant difference between control and treated groups in the diameter of the preovulatory follicles during the post treatment cycle. The endometrium thickness increased significantly in the L-GFequina and PRP groups ahead of the non-treated group. Intrauterine L-GFequina or PRP administration shortened the estrus cycle length. A higher pregnancy rate was recorded in the L-GFequina and PRP treated mares. In conclusion, the intrauterine infusion of L-GFequina or PRP increased the endometrial thickness and pregnancy rate and could be used to improve fertility in Arabian purebred mares who experienced from repeat breeding.