Peer-reviewed veterinary case report
Long-term methylene blue treatment for dog with hereditary
By Jaffey, J A et al.·Published in Journal of veterinary internal medicine·2017·Department of Veterinary Medicine and Surgery·View original on PubMed →
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Original publication title: Long-term Treatment with Methylene Blue in a Dog with Hereditary Methemoglobinemia Caused by Cytochrome b5 Reductase Deficiency.
- Species:
- dog
Plain-English summary
A young male mixed breed dog was brought in because he was very tired, had trouble exercising, and became aggressive when touched on the head. The vet noticed he had a blue tint to his gums, a fast heart rate, and rapid breathing, even when given oxygen. Tests showed he had a high level of methemoglobin, which is a condition where blood can't carry oxygen properly. After receiving methylene blue, the dog's symptoms improved, but they returned after 11 days. He was treated again with methylene blue by mouth, which helped reduce his symptoms and methemoglobin levels.
People also search for: dog lethargy and blue gums · methemoglobinemia treatment in dogs · methylene blue for dogs
Abstract
A juvenile male mixed breed dog was presented for lethargy, exercise intolerance, and aggression when touched on the head. Cyanosis, tachycardia, and tachypnea were observed and persisted during oxygen supplementation. Arterial blood gas analysis by co-oximetry identified an increased methemoglobin concentration (27%; normal, <2%) with normal arterial oxygen tension. The methemoglobinemia and associated clinical signs resolved after administration of methylene blue (1 mg/kg) IV, and the dog was discharged. The affected dog's whole-genome sequence contained 2 potentially causal heterozygous CYB5R3 missense mutations suggesting that cytochrome b5 reductase deficiency was responsible for the methemoglobinemia. This hypothesis was confirmed by enzyme analysis that identified cytochrome b5 reductase activity in the affected dog's erythrocytes to only approximately 6% of that in a control sample. Clinical signs recurred 11 days after discharge but normalized and the methemoglobin concentration decreased with methylene blue administration PO (1.5 mg/kg, initially daily and then every other day).
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/28963729/