Hovawart — Canine degenerative myelopathy, hereditary canine spinal muscular atrophy (hereditary; OMIA-verified breed predisposition)

--- license: permission_granted topic_id: companion_breed_health_hovawart_canine_degenerative_myelopathy_hereditary_canine_spinal_musc_dog category: companion-breed-health title: "Hovawart — Canine degenerative myelopathy, hereditary canine spinal muscular atrophy (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/hovawart_canine_degenerative_myelopathy_hereditary_canine_spinal_musc_506.txt date_parsed: 2026-08-02 tokens_estimated: 1256 verification: method: substring_match claims: 10 passed: 10 date: 2026-08-02 recovered: false path: companion-breed-health/companion_breed_health_hovawart_canine_degenerative_myelopathy_hereditary_canine_spinal_musc_dog/01_companion_breed_health_hovawart_canine_degenerative_myelopathy_hereditary_canine_spinal_musc_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: "Hovawart — Canine degenerative myelopathy, hereditary canine spinal muscular atrophy (hereditary; OMIA-verified breed predisposition)" url: "https://omia.org/OMIA000263/9615/" 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

Hovawart — Canine degenerative myelopathy, hereditary canine spinal muscular atrophy (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: Hovawart (Dog)
• Disorder: Canine degenerative myelopathy, hereditary canine spinal muscular atrophy
• Mode of inheritance: Autosomal recessive
• Summary: This is an adult onset degeneration of the spinal cord that progresses to paraplegia and tetraparesis. There is no successful treatment. A genetic test is available. A different mutation in the SOD1 gene causes an early onset disease: a href=../../../../../../OMIA002322/9615/OMIA:002322-9615/a : Dyskinesia, paroxysmal, SOD1-related in Canis lupus familiaris.
• Clin feat: Most dogs are at least 8 years of age at the onset of clinical signs, which include hyporeflexia, upper motor neuron proprioceptive spasticity and ataxia in the pelvic limbs. Widespread limb muscle atrophy can be observed and the disease progresses to paraplegia and eventually flaccid tetraparesis (Awano et al., 2009). Hyperesthesia, cranial nerve signs (e.g. difficulty in swallowing and barking), urinary and fecal incontinence (Coates et al., 2010) can be observed and in final stages of the disease respiratory muscles fail (Nardone et al., 2016). There is no effective treatment. [IT thanks DVM student Jane Lai for contributions to this entry in April 2022].
• Defect: yes
• Pathology: Histopathologic examination of the spinal cord is necessary for definitive diagnosis. Noninflammatory axonal and myelin degeneration is present at all levels of the spinal cord, being most severe in the dorsal lateral funiculus within the middle to caudal thoracic region. Segmental axonal and myelin degeneration, endoneurial fibrosis, hypomyelinated fibers and secondary demyelination are present in peripheral nerves. Axon cylinder vacuolization is characteristic (Coates et al., 2010).
• Prevalence: In an extensive project, Zeng et al. (2014) genotyped 33,747 dogs representing 222 breeds for both known mutant alleles, namely c.52T and c.118A. They concluded that the SOD1:c.118A allele is widespread and common among privately owned dogs whereas the SOD1:c.52T allele is rare and appears to be limited to Bernese Mountain Dogs. Full details are available in the paper. Mizukami et al. (2016) reported the frequency of the c.118A allele as 0.008 in 500 Border collies in Japan. Regarding the insertion reported by Turba et al. (2107), these authors reported that The allele containing the insertion was highly prevalent in Hovawart dogs, accounting for the 26.6% of allele frequency. The insertion was also found in other unrelated breeds such as Rough Collies and Standard Poodles. Santos et al. (2020) genotyped 97 German Shepherd dogs for the SOD1:c.118Ggt;A mutation using a PCR/RFLP test. The dogs were located in Brazil and had no clinical signs of degenerative myelopathy at the time of sampling. They “observed genotype frequencies (with 95% confidence interval) of: 0.758 (0.672-0.844), 0.242 (0.156-0.328) and 0.000 (0.000-0.000) for GG, AG and AA genotypes, respectively.” Maki et al. (2022) genotyped 541 German Shepherd Dogs (GSD) registered with the Japanese GSD Registration Society from 2000 to 2019, for the SOD1:c.118Ggt;A likely causal variant (omia.variant:36). They reported 330 G/G dogs (61%), 184 G/A dogs (34%), and 27 A/A dogs (5%), indicating a frequency of the mutant allele of 0.220. For each of the seven A/A dogs over 10 years old (this being an adult-onset disease), the owners reported DM-related clinical signs, indicating a clinical progression rate of 100%.
• Control: Due to the high frequency of the causative mutation in Boxers and Pembroke Welsh Corgis, in these breeds it is not practical to exclude carriers from breeding, so it is recommended that carriers be bred to noncarriers. Breeding of affected dogs of any breed should be avoided.
• Gen test: Investigating the many discordant findings between the parental and the offspring genotypes found by different laboratories in testing for the c.118Ggt;A variant, Turba et al. (2017) discovered An insertion of 54 nucleotides [in the SOD1 gene] composed of a poly-T stretch and 15 nucleotides containing the duplication of the exon 2-intron 2 junction was . . . responsible for the partial mismatch of the reverse primer used for a direct sequencing assay. The mismatch hampered the amplification of the corresponding allele and caused an evident drop-out effect. The insertion is in complete linkage disequilibrium with the c.118G allele. Santos et al. (2020) identified “a deletion of one “T” in the position 26540247 described as ENSCAFG00000008859:g.26540247del … located in the intron 1 of the SOD1 gene. … Although the role of the ENSCAFG00000008859:g.26540247del on structure and expression of SOD1 (and consequently its relationship with CDM) was not investigated in this study, its location does not suggest that it can influence the expression of the studied disease.” However, this variant prevented in a small number of dogs adequate genotyping of the SOD1:c.118Ggt;A in the PCR-RFLP test used in this study.

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: Entrez Gene ID 403559 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
• Gene: Entrez Gene ID 389416327 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
• OMIA molecular-genetics note: The first likely causative variant described is a G to A transition (c.118G&gt;A; p.E40K) in exon 2 of SOD1. All affected dogs tested were homozygous mutant. However, some homozygous mutant dogs had no signs of degenerative myelopathy, which suggests incomplete penetrance or other causative loci (Awano et al., 2009). The mutation is hypothesized to lead to SOD1 aggregation, as cytoplasmic inclusio…

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.

• 1994. Immunohistochemical evidence for immunoglobulin and complement deposition in spinal cord lesions in degenerative myelopathy in German Shepherd dogs. Can J Vet Res — PubMed:PMID8143248 — OMIA Phene_Article / Article
• 2002. Degenerative myelopathy in German shepherd dogs. Veterinary Record — OMIA Phene_Article / Article
• 2003. Molecular genetic and expression analysis of alpha-tocopherol transfer protein mRNA in German shepherd dogs with degenerative myelopathy. Berl Munch Tierarztl Wochenschr — PubMed:PMID12592926 — OMIA Phene_Article / Article
• 2008. Clinical characterization of a familial degenerative myelopathy in Pembroke Welsh Corgi dogs. J Vet Intern Med — PubMed:PMID18196743 — OMIA Phene_Article / Article
• 2009. Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy that resembles amyotrophic lateral sclerosis. Proc Natl Acad Sci U S A — PubMed:PMID19188595 | DOI:10.1073/pnas.0812297106 — OMIA Phene_Article / Article
• 2010. Canine degenerative myelopathy. Vet Clin North Am Small Anim Pract — PubMed:PMID20732599 | DOI:10.1016/j.cvsm.2010.05.001 — OMIA Phene_Article / Article
• 2009. Degenerative myelopathy in two Boxer dogs. Vet Pathol — PubMed:PMID19276068 | DOI:10.1354/vp.08-VP-0270-M-BC — OMIA Phene_Article / Article
• 2012. Genome-wide association studies for multiple diseases of the German Shepherd Dog. Mamm Genome — PubMed:PMID22105877 | DOI:10.1007/s00335-011-9376-9 — OMIA Phene_Article / Article
• 2013. Genotyping assays for the canine degenerative myelopathy-associated c.118G>A (p.E40K) mutation of the SOD1 gene using conventional and real-time PCR methods: a high prevalence in the Pembroke Welsh Corgi breed in Japan. J Vet Med Sci — PubMed:PMID23328634 | DOI:10.1292/jvms.12-0451 — OMIA Phene_Article / Article
• 2011. Immunohistochemical observation of canine degenerative myelopathy in two Pembroke Welsh Corgi dogs. J Vet Med Sci — PubMed:PMID21628865 | DOI:10.1292/jvms.11-0097 — OMIA Phene_Article / Article
• 2012. Degenerative myelopathy associated with a missense mutation in the superoxide dismutase 1 (SOD1) gene progresses to peripheral neuropathy in Pembroke Welsh corgis and boxers. J Neurol Sci — PubMed:PMID22542607 | DOI:10.1016/j.jns.2012.04.003 — OMIA Phene_Article / Article
• 2013. Neuronal loss and decreased GLT-1 expression observed in the spinal cord of Pembroke Welsh Corgi dogs with canine degenerative myelopathy. Vet Pathol — PubMed:PMID23839236 | DOI:10.1177/0300985813495899 — OMIA Phene_Article / Article
• (59 additional references in OMIA)

Comparative medicine (human OMIM)

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.

• OMIM:105400 (type: trait) — OMIA Group_OMIM (via OMIA_ID)
• OMIM:147450 (type: gene) — OMIA Group_OMIM (via OMIA_ID)
• OMIM:618598 (type: trait) — OMIA Group_OMIM (via OMIA_ID)

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."