Descriptive study of 32 cases of doxycycline-overdosed calves.
BACKGROUND
Reports of doxycycline-induced toxicity are limited despite common use of this antibiotic to treat infectious respiratory disorders in calves.


OBJECTIVE
To describe previously unreported kidney lesions and diagnostic test results in doxycycline-overdosed calves and to compare these results with other findings reported previously.


METHODS
Thirty-two calves that presented with adverse effects after receiving high doses of doxycycline as a treatment for mild respiratory disorders.


METHODS
Retrospective review of medical records.


RESULTS
Clinical examination identified mainly lethargy, dyspnea, cough, tongue paresia or paralysis associated with dysphagia and sialorrhea, tachycardia, tachypnea, and signs of myopathy. Blood analysis indicated increases in creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and sorbitol dehydrogenase activities and increased serum creatinine and urea concentrations. ECG recordings and Doppler echocardiography examination identified ventricular premature beats and a decrease in left ventricular global and systolic function, respectively. Necropsy and histopathology disclosed necrosis of the myocardium, tongue, and some striated muscles, acute renal tubular necrosis, and fatty degeneration or congestion of the liver.


CONCLUSIONS
Most of these findings corroborate previous observations made in doxycycline-overdosed calves, and further suggest myocardial and striated muscular toxicity as well as renal toxicity in doxycycline-overdosed calves.
Brihoum
M
M
Department of Companion Animals and Equids, Equine Clinic, B41, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium. mounir.brihoum@ulg.ac.be
Amory
H
H
Desmecht
D
D
Cassart
D
D
Deleuze
S
S
Rollin
F
F
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects*; D002417:Cattle; D002418:Cattle Diseases / Q000139:chemically induced* / Q000401:mortality; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000008:administration & dosage* / Q000009:adverse effects*; D062787:Drug Overdose; D005260:Female; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D012189:Retrospective Studies; D014059:Tongue / Q000473:pathology
D000900:Anti-Bacterial Agents; D004318:Doxycycline