Injuries to tendons are among the most common injuries in competition horses and represent a significant cause of morbidity and mortality. The present study aimed at an eight-week period ultrasonographic and biomechanical assessments of collagenase induced tendinitis in forelimb superficial digital flexor tendon (SDFT) in donkeys. Four healthy male donkeys were used. 1000 U collagenase type I from Clostridium histolyticum was injected in the center of the SDFT guided by ultrasonography. Ultrasonographical images of the SDFT were recorded prior to injury and 8 weeks after confirmation of tendinitis on a weekly basis. Images were digitized and lesion area to cross-sectional tendon area ratio (LA/TA ratios) was measured. At the end of the study period, the animals underwent tenectomy and tendon samples were evaluated biomechanically. Collagenase induced tendinitis was confirmed ultrasonographically 10 days post-injection. The animals showed swelling and response to palpation, however, no lameness was found in animals within the study period. There were significant differences between the first and the fifth weeks in operated limbs ultrasonographically (p < 0. 05). The eight-week period is sufficient to assess the effect of various modalities in tendon healing in the collagenase-induced model in the donkey. The development and expansion of collagenase induced tendinitis until week six after confirmation of tendinitis may disturb findings of the healing effect of various modalities in the tendon, in which tendinitis is still expanding and may mask the healing effect of the modalities used.

Introduction: The evaluation of musculoskeletal system in horse veterinary medicine is very important because of its effect on equine performance. The current study provided an ultrasonography description of the palmar tendons and ligaments of the metacarpus in pure Persian Arabian horses. Methods: The metacarpal regions of 10 healthy mare pure Persian Arabian horses were prepared for ultrasonography in respect of 6 regions (1, 2, 3, 4, 5, 6). For a better description, the left and right forelimbs of an adult healthy donkey was anatomically studied, too. Results: All the structures appeared with acceptable contrast and visibility at region 2. Echogenicity of Deep Digital Flexor Tendons (DDFT) from the 4th region was hyperechoic to isoechoic, compared to Superficial Digital Flexor Tendons (SDFT), and Suspensory Ligament (SL) of this level observed in the branching area was hyperechoic, in comparison to DDFT and SDFT; however, MSL and LSL were hypoechoic, compared to SDFT and DDFT. Additionally, the Inferior Check Ligament (ICL) and new discovered ligament (second superior check ligament) were detected in both anatomical and Ultrasonographical studies. There were no echogenicity differences between right and left forelimbs. Based on the obtained results, the Mean± SD maximum dorsopalmar thickness of SDFT, DDFT, AL and SL of the left forelimb were 6. 3± 0. 2, 8. 5± 0. 01, 5. 3± 0. 01, and 6. 7± 0. 3, respectively. Conclusion: The obtained data are strongly compatible with the previous findings in horses regarding the echogenicity and shape of palmar tendons and ligaments. Generally, it is assumed that transverse images better illustrate the tendons and ligaments.

Objective- To consider the possibility of ultrasonography evaluation of the plantar tendons and ligaments and prepare a standard reference for it.Design- Descriptive studyAnimals- 7 female healthy Caspian miniature horses'-age 7year- no clinical sign of lameness and prior to presentation.Procedure- The ultrasonography of the right and the left metatarsal region was performed using a Pie Medical 100 Falco Vet and an 8MHZ linear transducer. The area for ultrasonography was divided to 9 levels (1a-1b-2a-2b-3a-3b-4a-4b-5a), each 3 cm long afterwards.Results- All the structures started to appear with an acceptable contrast and visibility at the 2a level. SDFT and DDFT were well observed from the level 2a however, no definite borders were recognizable as ICL (except one case) and echogenicity of DDFT from the 2b level was hyperechoic to isoechoic comparing SDFT and SL from this level observed the branching area was hyperechoic in compare with DDFT & SDFT, however MSL & LSL were hypoechoic comparing SDFT and DDFT.There aren't any difference echogenicity between right and left hind limb.Conclusion and Clinical Relevance- Investigations have proved that there's no difference between the echogenicity of each ligament and tendon in different levels in the left and right limbs which was confirmed in the current inspection as well The conclusions of the current study on the Caspian horse were showen too that highly compatible with the previous vestigations in horses on echogenicity and shape of the plantar tendons and ligaments. Generally it is assumed that transverse images provide a better image of tendons and ligaments and any injury in any part of the above structures can be diagnosed easily, however some probable injuries around the tendon may be left unseen in longitudinal images.

Introduction: Topographic anatomy of the tendons and ligaments in healthy cases provides a normal atlas to diagnose abnormalities. The aim of this study was to provide ultrasonography description of the palmar tendons and ligaments of the Anatoly donkey. Methods: The metacarpal regions of 6 healthy Anatoly donkeys were prepared for ultrasonography and divided to 6 levels (1a, 1b, 2a, 2b, 3a, 3b), each 3 cm long apart. For better description, 2 left and right forelimbs were anatomically studied too.Results: All the structures started to appear with an acceptable contrast and visibility at 1b level. Echogenicity of deep digital flexor tendons (DDFT) from 2b level was hyperechoic to isoechoic compared to superficial digital flexor tendons (SDFT) and suspensory ligament (SL) from this level observed the branching area was hyperechoic in comparison to DDFT and SDFT; however MSL and LSL were hypoechoic compared to SDFT and DDFT. Also the inferior check ligament (ICL) and new discovered ligament (second superior check ligament) had been detected in both anatomical and ultrasonographic studies. There were not any echogenicity differences between right and left forelimbs.Conclusion: Previous investigations have proved that there is no difference between the echogenicity of each ligament and tendon at different levels in the left and right limbs which was confirmed in the current study as well. The findings of our study are also highly compatible with the previous findings in horses regarding echogenicity and shape of the palmar tendons and ligaments. Generally it is assumed that transverse images provide a better image of tendons and ligaments.

Superficial digital flexor tendon (SDFT) plays an important role in the locomotion of the horses with flexion of the limbs. In the hind limb, it passes over the calcaneal bone and attaches to medial and lateral surfaces of calcaneous by two bands of connective tissue; while, the medial band is weaker than the lateral one. Occasionally, severe trauma, over-extension or fracture of the calcaneous may cause rupture of the supportive bands leading to tendon luxation. An 11-year-old Thoroughbred jumping gelding with symptoms of lameness in both legs, after examination by an internal specialist veterinarian in equine practice field was referred to the Teaching and Research Hospital of the Faculty of Veterinary Medicine of the University of Tehran, Tehran, Iran. Clinical examination showed lateral luxation of SDFT in the right and left tarsal joints. Radiography revealed no sign of calcaneal involvement, except soft tissue swelling. In the radiography of the tarsal joints, the calcaneus bones did not show significant changes, but among the bones of the central and 3rd tarsal bone (distal intertarsal joint) of the tarsus, osteophyte formation was observed to a mild extent, indicating mild bone spavin in both tarsal joints. In ultrasonography, SDFT thickenings accompanied by hypoechoic regions in tendons were seen, confirming the signs of tendonitis. Moreover, fibrous tissue formation was diagnosed. In the left leg, anechoic fluid in the calcaneous bursa was seen. Evaluation of diagnostic imaging findings enables veterinarians to diagnose the site and extent of the lesions, choosing the appropriate therapeutic approach in addition to clinical symptoms.

Objective-To determine the effect of ultrasound therapy on hydroxyproline (HP) content in superficial digital flexor tendon (SDFT) in horses.Design - Experimental in vivo study.Animals - Eight adult castrated horses Procedure- The mediocaudal surface of right metatarsal bone in was exposed and after complete separation of SDFT, it was splitted (striking 15 times) in full thickness in longitudinal fashion of 10 cm in length in the mid-tendon area using BP blade no 24. These animals were divided into two equal groups of control and experiment. No treatment was given to control one, whereas; treatment group was subjected to therapeutic ultrasound (Sonopulse 434) regimens 10 minutes daily with intensity of 1 Watt/Esq. at 3 MHz frequency over 14 days. The hydroxyproline concentration was measured by modified spectrophotometery. The collected data was analyzed using student t test at p <0.05 significant level.Results- HP content of severed tendons in both groups was significantly less than normal tendons (P<0.01). Also, the HP content of treatment group was significantly more than the control group. Conclusion and Clinical Relevance- The results of this study indicated that direct application of ultrasound therapy on severely injured or extensive lesion of superficial digital flexor tendon in horses will enhance HP content in the treated tendon.