Shetland Sheepdog — canine spongiform leukoencephalomyelopathy; leucodystrophy; Shetland Sheepdog leukodystrophy (hereditary; OMIA-verified breed predisposition)

--- license: permission_granted topic_id: companion_breed_health_shetland_sheepdog_canine_spongiform_leukoencephalomyelopathy_leucodystrophy_sh_dog category: companion-breed-health title: "Shetland Sheepdog — canine spongiform leukoencephalomyelopathy; leucodystrophy; Shetland Sheepdog leukodystrophy (hereditary; OMIA-verified breed predisposition)" lang: en source: "OMIA (Online Mendelian Inheritance in Animals, University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; C1 substring-verified. Pulled 2026-08-02 from local OMIA database dump." source_file: pdf-raw/breed-health/shetland_sheepdog_canine_spongiform_leukoencephalomyelopathy_leucodystrophy_sh_5312.txt date_parsed: 2026-08-02 tokens_estimated: 628 verification: method: substring_match claims: 6 passed: 6 date: 2026-08-02 recovered: false path: companion-breed-health/companion_breed_health_shetland_sheepdog_canine_spongiform_leukoencephalomyelopathy_leucodystrophy_sh_dog/01_companion_breed_health_shetland_sheepdog_canine_spongiform_leukoencephalomyelopathy_leucodystrophy_sh_dog.md source_document: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" citation: authority: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" title: "Shetland Sheepdog — canine spongiform leukoencephalomyelopathy; leucodystrophy; Shetland Sheepdog leukodystrophy (hereditary; OMIA-verified breed predisposition)" url: "https://omia.org/OMIA002684/9615/" retrieved: "2026-08-02" ref: "OMIA breed-specific hereditary-disorder records (omia.org), derived from local OMIA database dump; dataset: https://doi.org/10.25910/2AMR-PV70" doc_type: "academic animal-genetics database (breed-specific disorder entries)" needs_review: false

Shetland Sheepdog — canine spongiform leukoencephalomyelopathy; leucodystrophy; Shetland Sheepdog leukodystrophy (hereditary; OMIA-verified breed predisposition)

Source: first-hand OMIA (University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; every claim below is a C1 byte-substring of it.

Claims

• Breed: Shetland Sheepdog (Dog)
• Disorder: canine spongiform leukoencephalomyelopathy; leucodystrophy; Shetland Sheepdog leukodystrophy
• Mode of inheritance: Mitochondrial
• Clin feat: Li et al. (2006): most affected [Australian cattle] dogs showed a moderate to severe generalized whole body tremor at 3–4 weeks of age. However, one affected pup in the third litter did not develop obvious neurological signs until 9 weeks of age. The tremor and dysmetric gait were typical of cerebellar involvement. All pups were initially able to ambulate but became progressively more ataxic over the next several weeks. Interestingly, each pup had a slightly different phenotypic expression of its disease, along with variability in the rapidity of disease progression. With time, the pups failed to grow, showed spasticity in all four limbs, and had an inability to ambulate with eventual lateral recumbency. ... Vision and audition remained intact as did nociception. Electrophysiological testing of CNS function showed abnormal brainstem auditory evoked responses with conduction delay, which was also seen in studies of conduction in the spinal cord ... . ... Affected [Shetland sheepdog] pups were smaller than normal littermates. The neurologic defects were variable, ranging from mild to severe and consisted of tremor, ataxia, paresis, rigidity and spasticity, inability to ambulate, dysphagia, and seizures. Clinical signs developed between 7 days and 3 weeks with some pups dying by 7 weeks of age. All laboratory blood testing was normal, although a CT scan of one affected pup showed dilation of the lateral and 4th ventricles and diffuse hypomyelination of the white matter (Wood and Patterson, 2001).
• Defect: yes
• Pathology: Li et al. (2006): In both breeds, widespread vacuolation of myelin was found in subcortical white matter, cerebellum, brain stem, and spinal cord ... , while no pathological changes were found in lung, heart, small intestines, jejunum, spleen, liver, and kidney. Axons surrounded by vacuolated myelin appeared intact, and occasional scattered demyelinated axons were noted ... . However, some axons appeared to be degenerating ... , and in severely affected areas, axonal loss and gliosis were seen ... . The degree of vacuolation varied from dog to dog in the spinal cord and also varied in its degree and tract location along the cord in the same animal. Occasional areas of normal myelin were seen ... .

Associated gene(s)

Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.

• Gene: cytB (Entrez Gene ID 26753425) — OMIA Phene_Gene / GeneSynonym
• OMIA molecular-genetics note: Li et al. (2006) showed that this disorder is due to a missense variant in the mitochondrial gene for cytochrome b. The variant is a G>A transition as position 14,474 of the mitochondrial genome (NC_002008) predicted to result is a p.V98M substitution on the protein level. This is the first report in domesticated animals of a naturally-occurring base substitution in a mitochondrial gene, leading t…

Evidence (references)

Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.

• 2001. Shetland Sheepdog leukodystrophy. Journal of Veterinary Internal Medicine — PubMed:PMID11596738 — OMIA Phene_Article / Article
• 2006. Canine spongiform leukoencephalomyelopathy is associated with a missense mutation in cytochrome b. Neurobiol Dis — PubMed:PMID16026996 | DOI:10.1016/j.nbd.2005.06.009 — OMIA Phene_Article / Article
• 2022. Mitochondrial DNA alterations in the domestic dog (Canis lupus familiaris) and their association with development of diseases: A review. Mitochondrion — PubMed:PMID35134592 | DOI:10.1016/j.mito.2022.02.001 — OMIA Phene_Article / Article
• 2023. An overview of canine inherited neurological disorders with known causal variants. Animals (Basel) — PubMed:PMID38003185 | DOI:10.3390/ani13223568 — OMIA Phene_Article / Article

verification_derived: method: derived_from_dataset source: "OMIA database dump (omia.xml, local); fields Gene/Variant/Article/OMIM" note: "Structured fields (gene, variant rsID/protein change, PubMed/DOI references, OMIM cross-link) extracted from OMIA dump and presented with first-hand values; not verbatim prose."