EFFECTS OF DOXYCYCLINE HYCLATE, ONE PERCENT POLIDOCANOL, AND ABSOLUTE ETHANOL ON THE CUTANEOUS AND SUBCUTANEOUS TISSUES OF CHICKENS (GALLUS GALLUS DOMESTICUS) AND THE POTENTIAL IMPLICATIONS IN TREATING CERVICOCEPHALIC DIVERTICULA RUPTURE.

The objective of this pilot study was to examine the histologic effects associated with three known sclerosing agents and their ability to induce fibrosis in the subcutaneous space between the cervicocephalic air sac and skin. In the future, these drugs may prove useful in treating birds experiencing cervicocephalic diverticula rupture. The agents used were 1% polidocanol, absolute ethanol, and doxycycline hyclate. Twelve healthy adult chickens (Gallus gallus domesticus) were used in this study. The chickens were randomly allocated into three groups denoting day of euthanasia (day 4, 7, or 14). On day 0, all agents were injected (0.2 ml) subcutaneously, in a four-point grid fashion, in both the cervical and pectoral region of each bird. After euthanasia, the skin and subcutaneous tissues corresponding to the injection sites were harvested for histologic assessment. Tissue sections were assessed for fibrosis and lymphocytic and histiocytic inflammation. A scoring system was established to rank sclerosing agents by fibrosing and inflammatory ability. In the cervical region of chickens, 1% polidocanol induced the greatest inflammatory changes by day 7. Data suggest that doxycycline hyclate may produce the greatest cutaneous and subcutaneous fibrosis overall among all groups of birds. No adverse reactions were associated with any injection. Sterile saline produced the least amount of inflammation when assessed with the scoring system. Further investigation is needed to determine the safety of injections of larger volume with these chemicals and whether these findings can be extrapolated to birds with disease.