STUDIES ON PROPENTOFYLLINE FOR THE TREATMENT OF NAVICULAR DISEASE

An orally administered hemorheologic drug, propentofylline, was evalua ted for the treatment of navicular disease. In a preclinical trial, 6 normal horses and 3 with navicular disease were administered the drug for 3 consecutive 30-day periods at incremental dose rates of 5, 10 an d 15 mg/kg twice daily, respectively. An adverse response to the medic ation was assessed for by monitoring physical, complete blood count an d serum biochemistry parameters, and by completing a necropsy examinat ion. No abnormalities were noted in response to drug administration. A pharmacological effect was sought by monitoring the drug's influence on platelet aggregation percent (PAP) and rate (PAR). A significant (P <0.05) difference in the baseline value for both platelet parameters, as well as the response to medication, was noted between normal and na vicular horses. Drug efficacy was assessed in a clinical trial using 1 0 horses with navicular disease. The drug was administered at 7.5 mg/k g twice daily for 6 weeks. Response to treatment was evaluated using a standardized lameness examination and force plate gait analysis. Both tests indicated that a significant (P<0.05) improvement in lameness o ccurred in response to the drug, but a return to complete soundness wa s not achieved in any horse within the time frame of the investigation .