Ultrasound-guided injection of the cranial tibial artery for stem cell administration in horses.

BACKGROUND: A technique for intra-arterial injection of mesenchymal stem cells (MSC) has been established for front limbs with the use of the median artery. This approach has been proposed for treatment of soft tissue injuries of the equine distal limb. A technique has not been validated yet for hindlimb injection. OBJECTIVES: To assess the feasibility of injection of the cranial tibial artery in horses, and to evaluate the distribution and persistence of MSC after injection. STUDY DESIGN: In vivo experiment. METHODS: In a first phase, the cranial tibial arteries of both hindlimbs of three research horses were catheterised with ultrasound guidance under general anaesthesia and injected with iodinated contrast. In the second phase, iodinated contrast was injected in three standing sedated horses with ultrasound guidance. In the final phase, 99m Technetium-HMPAO labelled allogenic bone marrow derived equine MSC were injected under standing sedation with the same technique in three other horses. Scintigraphy was used to assess MSC distribution and persistence for 24 h. Ultrasound was performed 24 h after injection to assess vessel impairment. RESULTS: Arterial injection was achieved in all 18 limbs without any significant complications. Mild partial periarterial injection was observed in four limbs. Scintigraphic images demonstrated diffuse MSC distribution from the tarsal area to the foot. Persistence decreased over time but signal was still present at 24 h. MAIN LIMITATIONS: Limited retention of the radiolabel in the MSC. CONCLUSIONS: Ultrasound-guided injection of the cranial tibial artery can be performed both under general anaesthesia and standing sedation in horses. This technique could be used for MSC treatment of equine proximal suspensory desmopathy or other injuries in the distal hindlimb.

Cardiac adaptations in SCNT newborn cloned calves during the first month of life assessed by echocardiography.

The aim of this study was to compare cardiac morphology in newborn and month-old control and cloned calves. A total of 10 in vivo-derived (IVD) control (five Holstein, five Hereford) and seven cloned (five Holstein, two Hereford) calves were subjected to echocardiographic examination, including 2D, M-mode, spectral and color flow Doppler evaluation at Day 1 (mean 26.3 h) and Day 30 (mean 29.2 days) after birth. Echocardiographic measurements were compared between control and cloned calves, and between Hereford and Holstein control calves of the same age. At Day 1 and at Day 30 after birth, left ventricular free wall (LVFW) and interventricular septal (IVS) thicknesses were greater in Holstein calves than Hereford calves. Several indices of myocardial wall thickness were increased in cloned versus control calves at Day 1 after birth, and included systolic LVFW thickness, systolic right ventricular free wall (RVFW) thickness, diastolic LVFW thickness, diastolic RVFW thickness and diastolic IVS thickness (p < 0.05). Differences between cloned and non-cloned calves were no longer evident at Day 30 after birth. The apparent disappearance of the cloning effect on cardiac structures may reflect the influence of placenta on fetal cardiac morphology, suggestive of a placental hemodynamic role in fetal cardiac muscle development. Differences seen in clones at birth spontaneously resolved by Day 30 of age, after organ development recovery from cardiovascular abnormalities of presumed placental origin. Echocardiographic measurements should provide useful data for research and clinical evaluation of high-risk neonatal calves of both breeds and from clones of the same breed.

Ultrasonographic appearance of normal and injured lateral patellar ligaments in the equine stifle.

REASONS FOR PERFORMING STUDY: Ultrasound is widely used in horses with stifle lameness, yet limited information is available regarding the appearance of normal and injured lateral patellar ligaments (LPL). OBJECTIVES: To map the normal ultrasonographic appearance of the LPL. To describe the clinical and ultrasonographic features of LPL injuries. STUDY DESIGN: Descriptive study of healthy horses and retrospective case series. METHODS: Twelve horses without stifle lameness underwent ultrasonographic examination of bilateral LPLs and ultrasonographic features were recorded. Eighteen horses with LPL injury were identified from 1999 to 2011. RESULTS: The normal LPL changes in appearance from origin to insertion. It shows ill-defined margins at the patella, becomes flattened and bilobed over the lateral trochlear ridge, is oval-triangular shaped with variable echogenicity and fibre pattern distal to the LTR, and becomes tapered with striations at the tibial insertion. LPL injury was identified in 18 horses of multiple breeds and uses. All injuries were acute, and 12 had wounds. Eleven horses were severely lame (grade 4-5/5). Ultrasonographic lesions were severe in 78% of cases. The mid to insertional portion of the LPL was most often affected. Radiography showed fractures of the tibial tuberosity (n = 6), patella (n = 4) and lateral trochlear ridge (n = 1). Fractures involved LPL attachments in 9 horses. Five were treated for osteomyelitis and one for synovial sepsis. Recheck ultrasound in 4 horses showed minimal to no change in the appearance of LPL injuries. Nine horses returned to riding, one continued as a broodmare, 2 were retired, one became a broodmare, 2 were lost to follow-up and 3 were subjected to euthanasia owing to concurrent injuries. CONCLUSION: Normal variations in shape, echogenicity and fibre pattern of the LPL are important considerations to prevent false positive diagnoses during ultrasonography. LPL injuries were often severe and associated with craniolateral stifle trauma. Prognosis varied from good to guarded in horses without additional severe injuries.

Septic sialoadenitis in equids: a retrospective study of 18 cases (1998-2010).

REASON FOR PERFORMING STUDY: Septic sialoadenitis, although uncommonly reported in equids, is a significant cause of pain, inappetence, dysphagia and discomfort. There are currently few reported cases possibly as a result of its infrequent occurrence. OBJECTIVES: To review cases presenting with sialoadenitis and describe the presenting complaints, results of diagnostic tests, treatment and outcome. STUDY DESIGN: Retrospective case series. METHODS: Records were reviewed for equids presenting to the UC Davis William R. Pritchard Veterinary Medical Teaching Hospital between 1998 and 2010 for salivary gland swelling. Equids were included if a diagnosis of septic sialoadenitis was made based on a combination of oral examination and/or ultrasonographic findings and/or microbial culture. Data collected included age, breed, presenting complaints, diagnostic results, treatment and outcome. RESULTS: Eighteen equids were diagnosed with septic sialoadenitis affecting the parotid gland (11) or the mandibular salivary gland (7). Ultrasound was useful to differentiate whether the mandibular or parotid salivary gland was involved. Affected equids ranged in age from 4 to 30 years (mean 17.7 years). Fourteen of 15 (93.3%) equids that underwent a complete oral examination had dental or other oral abnormalities. Six of 18 cases had evidence of sialolithiasis. Culture of the infected salivary gland or secretions was performed in 9 equids and all yielded growth of Fusobacterium sp. along with other aerobic and anaerobic bacteria. Infection resolved in 15/18 cases (83.3%) and 2/18 (11.1%) were subjected to euthanasia. CONCLUSIONS: Dental disease and sialolith formation may play important roles in the development of septic sialoadenitis in equids. Anaerobic infection should be assumed in all cases and affected horses should be treated for this until culture and sensitivity results are available. Prognosis is favourable (83.3%) with appropriate treatment.

Intestinal neoplasia in horses.

BACKGROUND: Intestinal neoplasia of horses is inadequately described. HYPOTHESIS: Intestinal neoplasia of horses has characteristic clinicopathologic features. ANIMALS: Thirty-four horses with intestinal neoplasia. METHODS: Retrospective study. RESULTS: Anamnesis, clinical signs, clinicopathologic and pathologic findings in 34 adult horses diagnosed histologically with intestinal neoplasia were reviewed. The horses ranged in age from 2 to 30 years (mean 16.6 years at presentation). The Arabian breed was most represented and there was no sex predisposition. The most common presenting complaints were weight loss, colic, anorexia, and fever. The most consistent clinical signs were poor body condition, tachycardia, tachypnea, fever, and diarrhea. Useful diagnostic tools included rectal examination, routine blood analyses, abdominocentesis, ultrasonographic examination, rectal biopsy, and exploratory laparotomy. Alimentary lymphoma was the most common intestinal neoplasia identified, followed by adenocarcinoma and smooth muscle tumors. The small intestine was the most common segment of intestine affected for all neoplasms. Intestinal neoplasia was diagnosed antemortem in 13 of 34 (38%) horses. The median time from onset of clinical signs to death or euthanasia was 1.9 months. The discharge rate was 15%. Although the longest survival was observed in horses with jejunal adenocarcinoma, all horses were eventually euthanized because of intestinal neoplasia. CONCLUSIONS: Arabian horses were 4.5 times more likely to have intestinal neoplasia diagnosed than were other breeds.

Metallic foreign bodies in the tongues of 16 horses.

The history, clinical signs, results of diagnostic imaging, treatment methods and outcome of 16 adult horses with a metallic foreign body in the tongue are reviewed. All the horses had a swollen tongue, they salivated excessively and were partially to completely anorexic. Less common clinical signs were fever, an enlarged and painful intermandibular space, dysphagia, unilateral tongue paralysis and halitosis. Most of the horses had shown clinical signs for less than 24 hours. The foreign bodies were diagnosed by oral examination, radiography and ultrasonography; they were removed from the tongue of four of the horses during the initial oral examination, and were removed surgically from nine others; the other three horses were treated medically without attempts being made to extract the foreign bodies. Twelve of the bodies were small pieces of wire and one was a hypodermic needle. All the horses received a combination of antimicrobial and non-steroidal anti-inflammatory drugs and they all made an uneventful recovery. Feeding hay and the use of cable-framed tractor tyres as feeders were commonly associated with the cases.

Risk factors for and outcomes of noncatastrophic suspensory apparatus injury in Thoroughbred racehorses.

OBJECTIVE: To evaluate effects of toe grabs, exercise intensity, and distance traveled as risk factors for subclinical to mild suspensory apparatus injury (SMSAI) in Thoroughbred racehorses and to compare incidence of severe musculoskeletal injury (MSI) in horses with and without SMSAI. DESIGN: Nested case-control study. ANIMALS: 219 Thoroughbred racehorses racing or in race training. PROCEDURE: Racehorses were examined weekly for 90 days to determine incidence of suspensory ligament injury and monitor horseshoe characteristics. Every horse's exercise speeds and distances were recorded daily. Conditional logistic regression was used to compare exposure variables between incident case (n = 25) and selected control (125) horses. Survival analysis was used to compare time to MSI for horses with (n = 41) and without (76) SMSAI. RESULTS: The best-fitting logistic model for the data included age (< 5 vs > or = 5 years old), toe grab height the week of injury (none vs very low, low, regular, or Quarter Horse height), and weekly distance the week preceding injury (miles). Although the 95% confidence intervals for all odds ratios included 1, the odds for SMSAI appeared to increase with the presence of a toe grab, higher weekly distance, and age > or = 5 years. Horses that had SMSAI were significantly more likely to have a severe MSI or severe suspensory apparatus injury than were horses that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that pre-existing SMSAI is associated with development of severe MSI and severe suspensory apparatus injury. Modifying training intensity and toe grab height for horses with SMSAI may decrease the incidence of severe MSI.