Peer-reviewed veterinary case report
How phenylephrine helps locate nerve damage in dogs with Horner's
By Simpson, Katherine M et al.·Published in Veterinary ophthalmology·2015·Dick White Referrals, United Kingdom·View original on PubMed →
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Original publication title: Neuropharmacological lesion localization in idiopathic Horner's syndrome in Golden Retrievers and dogs of other breeds.
- Species:
- dog
Plain-English summary
A group of 10 Golden Retrievers, aged 4 to 13 years, were brought in for drooping eyelids and a smaller pupil on one side, signs of Horner's syndrome. After testing with a medication called phenylephrine, eight of the dogs were found to have a type of nerve damage that typically resolves on its own. All the affected dogs showed improvement within 11 to 20 weeks, and none had any recurrences. This suggests that while the exact cause of Horner's syndrome in these dogs is still unclear, most cases in Golden Retrievers are not as serious as previously thought.
People also search for: Golden Retriever drooping eyelid · Horner's syndrome treatment in dogs · why is my dog's pupil smaller?
Abstract
OBJECTIVE: To investigate whether idiopathic Horner's syndrome (HS) in Golden Retrievers is an exclusively preganglionic disorder based on denervation hypersensitivity pharmacological testing with phenylephrine. ANIMALS STUDIED: Medical records of dogs presented with HS between 2000 and 2012. Dogs presented with additional ocular or systemic signs were excluded. PROCEDURES: Clinical data examined included age, sex, duration of clinical signs, ancillary diagnostic test results, and time to mydriasis on topical ocular application of 1% phenylephrine. Lesions were diagnosed as postganglionic (mydriasis within 20 min) or preganglionic (mydriasis between 20 and 45 min). RESULTS: Medical records of 21 dogs of nine different breeds were included. An etiopathogenesis for Horner's syndrome was determined in five dogs, none of which were Golden Retrievers. All diagnoses correlated with pharmacological lesion localization. Ten Golden Retrievers were included (eight male and two female) with a mean age of 8.5 years (range: 4-13). Lesion localization was diagnosed as postganglionic in eight (mean: 10 min [range: 6-18]) and preganglionic in two Golden Retrievers (20 and 24 min). All cases were unilateral and had completely resolved within 15 weeks (range: 11-20). Recurrence was not reported in any of the patients. CONCLUSIONS: Idiopathic postganglionic HS was diagnosed in eight of 10 Golden Retrievers contradicting previous reports of a purely preganglionic localization. Etiopathogenesis of canine idiopathic HS remains to be determined; nevertheless, a vascular etiology cannot be excluded. Future studies using magnetic resonance angiography may aid in clarifying the pathogenesis.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/24028692/