Erythrodermatitis is an infectious-contagious disease that can have a subacute to chronic course and affects various fish species, including carp. The etiological agent of the disease is often represented by the bacterium Aeromonas hydrophila. Poor water quality, temperature fluctuations and high stocking densities can stress fish and compromise their immune systems, making them more susceptible to bacterial infections such as erythrodermatitis.
In the current study, carp at the fish farm in Galați County, were treated with florfenicol last year to combat erythrodermatitis. This year, the above-average temperature increase in early April favored the resurgence of erythrodermatitis in carp
The clinical signs of bacterial infection were evident in terms of lesions: swollen abdomen, integumentary bleeding in the abdomen, hemorrhagic ulcers in the fins, multiple adhesions in the visceral mass/abdominal cavity, perforated and hemorrhagic intestine in the posterior region (the dissection revealed the presence of intestinal contents /food bowl in the abdominal cavity).
The bacteriological examination and the clinical and anatomopathological examinations helped identify the disease-causing agent. Physiological stress, caused by the pathogenic bacteria, was evident in the blood analysis: a decrease in red blood cell count and hemoglobin content, and an increase in the number of neutrophils and monocytes.
Recommendation: It is important to maintain optimal water quality parameters to reduce stress and improve the immune response. Regularly monitor water temperature and take measures to prevent overheating. Keep an eye on fish health for early detection of disease outbreaks. In case of bacterial outbreaks, treat them with specific antibiotics and disinfect equipment to reduce the risk of recurrence.