Peer-reviewed veterinary case report
Boxer dogs losing consciousness briefly due to hypothyroidism
By Broome, Harriet A O et al.·Published in BMC veterinary research·2025·Small Animal Teaching Hospital, United Kingdom·View original on PubMed →
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Original publication title: Transient loss of consciousness in boxer dogs with hypothyroidism: 3 cases (2015-2018).
- Species:
- dog
Plain-English summary
Three Boxer dogs, aged 7 to 11 years, were brought to the vet because they experienced episodes of fainting or losing consciousness. After thorough examinations and tests, including heart monitoring, the dogs were diagnosed with hypothyroidism, a condition where the thyroid gland doesn't produce enough hormones. They were all started on a medication called levothyroxine, and their fainting episodes improved or completely resolved with treatment. This suggests that if your Boxer is having similar symptoms, hypothyroidism could be a possible cause.
People also search for: Boxer dog fainting · hypothyroidism in dogs · levothyroxine for dogs · dog loss of consciousness treatment
Abstract
BACKGROUND: Three Boxers, two neutered females and one neutered male, aged from seven to eleven years, were presented for investigation of transient loss of consciousness. CASE PRESENTATION: In each case, physical examination revealed no significant abnormalities and echocardiography, and electrocardiography did not identify a cause of transient loss of consciousness. Twenty-four-hour electrocardiogram (Holter) monitoring was performed in all three dogs. One dog had an episode of transient loss of consciousness whilst wearing the Holter, during which second-degree atrioventricular block and sinus bradycardia were observed. Based on clinicopathological testing, all three dogs were diagnosed with hypothyroidism. Once hypothyroidism was diagnosed all dogs were started on levothyroxine. In all cases the transient loss of consciousness resolved or improved once the treatment was started. CONCLUSION: Hypothyroidism should be considered as a differential diagnosis in Boxers presenting with transient loss of consciousness. Treating hypothyroid Boxers may decrease or resolve the clinical signs.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41398279/