Monika Gangl

Evaluation of low-molecular-weight heparin for the prevention of equine laminitis after colic surgery

OBJECTIVES The aim of this study is to describe the prevalence of postoperative laminitis in colic cases and to determine if low-molecular-weight heparin (LMWH) is effective in preventing this complication. DESIGN Retrospective clinical study. ANIMALS Client-owned horses. Interventions- SC administration of enoxaparin during the postoperative period. MEASUREMENTS AND MAIN RESULTS Medical records of 360 horses undergoing surgery for colic and surviving at least 3 days were evaluated. Fifty-six horses admitted before 1995 did not receive LMWH (control group) and 304 admitted after 1995 received LMWH as a prophylaxis for laminitis (treatment group). Three grades of severity were defined for laminitis. Prevalence and severity of laminitis were compared between the 2 groups. Several parameters recorded on admission (sex, age, breed, site and nature of the disease, heart rate, PCV, gravity score, and shock score) and the administration of LMWH were tested as risk factors in the development of laminitis in a logistic regression procedure. Prevalence and grade of laminitis were significantly lower in the treatment group. Only the absence of LMWH was recognized as a significant risk factor in the logistic regression model. CONCLUSIONS The administration of LMWH appears to be effective in the prophylaxis of laminitis following colic surgery and may be useful in the postoperative management of these horses.

Retrospective study of 99 cases of bone fractures in cattle treated by external coaptation or confinement

Between 2000 and 2003, 99 cattle with limb fractures were treated. Over 50 per cent were tibial fractures, with the femur and os calcis being the second and third most frequently affected bones. Eight of the cattle were slaughtered because of their poor prognosis, 10 were treated by stall confinement, 76 were treated by external coaptation with a Thomas splint-cast combination and three were treated with a simple or reinforced half limb cast; these 79 cattle were usually discharged immediately. One calf was treated with internal fixation, and another by amputation. Follow-up information was obtained by telephone, and the treatments were classified as either completely successful (return to previous production level), partially successful (return to lower production level) or failure. Forty (52·6 per cent) of the cattle treated with the Thomas splint-cast combination were classified as a complete success and 14 (18·4 per cent) as a partial success; the treatment failed in 19 of the cattle and three were lost to follow-up. The animals’ bodyweight, age and sex, and whether the fracture was open or closed, had no significant influence on the outcome. Among the 10 cattle treated for proximal fractures by stall confinement, there were five survivors, four non-survivors and one was lost to follow-up.

Relationship between biochemical markers and radiographic scores in the evaluation of the osteoarticular status of Warmblood stallions

Establishing the osteoarticular status of the horse is often performed by means of radiological screening of the animals. Widespread blood sampling could reveal to be an interesting alternative to this procedure which is time consuming and sometimes technically difficult. The aim of this study was to investigate the relationship between the radiological status of the horses and the levels of biochemical markers of cartilage degradation and synovial inflammation. A specific radiological scoring and classification system was therefore developed and applied on 63 stallions presented for studbook admission. Additionally, groups of horses were established according to the occurrence of osteochondrosis, degenerative joint disease and distal interphalangeal joint effusion. Insulin growth factor-I, myeloperoxidases, Coll2-1 and Coll2-1NO(2) were used as blood markers. The combination of the blood parameters did not seem to correlate with the used scoring system. Coll2-1NO(2) levels however tended to increase with poorer radiological class and this could therefore potentially be a useful predictor of the osteoarticular status in the horse. Coll2-1 levels were significantly higher in the degenerative joint disease group. A high percentage of horses with distal interphalangeal joint effusion was present in this study and was associated with decreased IGF-I and increased Coll2-1 levels.

Comparison of thiopentone/guaifenesin, ketamine/guaifenesin and ketamine/ midazolam for the induction of horses to be anaesthetised with isoflurane

Forty-eight horses subjected to elective surgery were randomly assigned to three groups of 16 horses. After premedication with 0-1 mg/kg acepromazine intramuscularly and 0.6 mg/kg xylazine intravenously, anaesthesia was induced either with 2 g thiopentone in 500 ml of a 10 per cent guaifenesin solution, given intravenously at a dose of 1 ml/kg (group TG), or with 100 mg/kg guaifenesin and 2.2 mg/kg ketamine given intravenously (group KG), or with 0.06 mg/kg midazolam, and 2.2 mg/kg ketamine given intravenously (group KM). Anaesthesia was maintained with isoflurane. The mean (sd) end tidal isoflurane concentration (per cent) needed to maintain a light surgical anaesthesia (stage III, plane 2) was significantly lower in group KM (0.91 [0.03]) than in groups TG (1.11 [0.03]) and KG (1.14 [0.03]). The mean (sd) arterial pressure (mmHg) was significantly lower in group KG (67.4 [2.07]) than in groups TG (75.6 [2.23]) and KM (81.0 [2.16]). There were no significant differences in the logarithm of the heart rate, recovery time or quality of recovery between the three induction groups. However, pronounced ataxia was observed in the horses of group KM, especially after periods of anaesthesia lasting less than 75 minutes.

Plasma Concentration of Insulin-like Growth Factor I (IGF-I) in Growing Ardenner Horses Suffering from Juvenile Digital Degenerative Osteoarthropathy

Degenerative osteoarthropathy resulting in a reduced active lifespan was observed in Ardenner horses. In the context of joint biology, insulin-like growth factor I (IGF-I) is a potential candidate to affect the anabolism of cartilage matrix molecules. A group of 30 Ardenner horses reared under standardized conditions from weaning were evaluated periodically from 15 to 28 months of age to detect the early manifestations of the disease. At the end of this period, horses were classified in two pathological groups related to the degree of interphalangeal degenerative osteoarthropathy based on clinical and radiographic evaluations: healthy (46.7%) and pathological (53.3%) horses. Seven sequential blood samples were taken from each horse (during the evaluation period) to study the variation of IGF-I plasma concentration. We tested the variations of the IGF-I plasma concentration during growth, and the effect of sex and of pathological classes. Significant variations were observed during the research period, with a maximum value corresponding to spring and a minimum in autumn. A significant reduction of the IGF-I plasma concentration was also observed in the pathological horses (433.5 ± 19.5 ng/ml) compared to the healthy horses (493.9 ± 18.2 ng/ml). An alteration in the level of this growth factor could induce a disregulation of the mechanisms involved in the local control of joint and bone tissue development.

Variations of plasmatic concentrations of Insulin-like Growth Factor-I in post-pubescent horses affected with developmental osteochondral lesions.

Developmental osteochondral lesions are often encountered in the equine population and are a major cause of lameness. Different growth factors that act systemically as well as locally regulate the growth of cartilage. Among them is Insulin-like Growth Factor I that has been demonstrated to promote chondrocyte growth and differentiation and that has been shown to influence cartilage repair. The aims of this study were to investigate differences in circulating plasma levels of Insulin-like Growth Factor-I in post-pubescent horses affected with developmental osteochondral lesions compared to unaffected ones. Significantly higher values of circulating Insulin-like Growth Factor-I levels were found in the affected group (n = 82) compared to controls (n = 86). This result may still reflect an earlier imbalance in IGF-I levels from horses with developmental osteochondral lesions considering the aetiopathological link which has been made between IGF-I and the occurrence of osteochondrosis. However, other studies have shown increased expression of IGF-I after cartilage damage. The higher levels found in this study could be due to a healing response of the cartilage to the damage caused by the osteochondral lesions.

Plasma Concentrations of a Type II Collagen-derived Peptide and Its Nitrated Form in Growing Ardenner Sound Horses and in Horses Suffering from Juvenile Digital Degenerative Osteoarthropathy

Several breeds of draft horses suffer from degenerative digital osteoarthropathy, resulting in a reduced active lifespan. A group of 30 Ardenner horses was followed, in standardized conditions, from 15 to 28 months of age to detect the early manifestations of the disease. The severity of the disease was assessed according to a personal grading system including clinical and radiographic items. Coll 2-1, a peptide of the helical region of type II collagen, and its nitrated form (Coll 2-1 NO2) were assayed in blood plasma collected at 452 ± 18 days, 504 ± 20 days, 558 ± 18 days, 613 ± 19 days, 675 ± 19 days, 752 ± 21 days and 852 ± 19 days of age. At the end of the follow-up period, 53.3% of Ardenner horses were affected by a degenerative digital osteoarthropathy. A significant effect (p < 0.05) of time, sex and pathology was observed for Coll 2-1 NO2. Variations of Coll 2-1 were not significant except for the time effect. The elevation of Coll 2-1 NO2 in the pathological group could indicate an inflammatory process during the growth of the affected horses, as nitration of tyrosine is mediated through reactive oxygen/nitrogen species and/or myeloperoxidase activity. Coll 2-1 NO2 appears to be an interesting early marker of cartilage degradation and oxidation in degenerative osteoarthropathy.