Effects of Phenobarbital and Prednisolone on Neurological Signs of Canine Distemper

Canine distemper virus (CDV) is a highly infectious and often fatal disease in dogs, affecting various systems. Despite vaccination efforts, cases of distemper, especially the neurological form, remain a global concern due to its high fatality rate.

To investigate the effectiveness of phenobarbital and prednisolone in treating the neurological form of canine distemper (CD).

Thirty-five dogs with neurological signs of CD were included in the study after careful clinical examination. Confirmation of CD was based on clinical signs, rapid diagnostic tests, and RT-PCR testing of blood and/or cerebrospinal fluid (CSF). Dogs were treated with oral phenobarbital (2.5 mg/kg) and prednisolone (0.55 mg/kg) every 12 h. Treatment outcomes were categorised as recovered, died, or euthanised.

Out of the 35 dogs, 25 tested positive for CDV. Among positive cases (n = 25), two dogs mostly recovered, one dog partially recovered, one dog remained unchanged, 18 died (15 died naturally and three were euthanised), and three dogs were lost to follow-up. In the negative test group (10 dogs), eight dogs died, the outcome of one dog was unknown and one dog remained unchanged. Disease duration ranged from 2 to 586 days (average: 72 days in positive cases, 59.2 days in negative cases). The low recovery rate (8%) suggests limited effectiveness of the treatments used, including prednisolone, particularly for myoclonus, which was the most frequent clinical sign. Regarding seizure management, while our study observed some effectiveness of phenobarbital in controlling seizures, it's important to note that the efficacy of phenobarbital can vary.

Small sample size and owner non-compliance limited the study.

Our findings suggest limited benefit from prednisolone for neurological CD. Further research is necessary to develop more effective treatment strategies for this devastating canine viral disease.