Juvenile, fatal hereditary nephropathy of the English Cocker Spaniel due to a collagen IV defect (COL4A4): glomerulopathy with thickening and splitting of the glomerular basement membrane, progressive proteinuria and renal failure. A canine model of human Alport basement membrane nephropathy. It is inherited in an autosomal recessive manner. Test referred to an external laboratory.

English Cocker Spaniel: frequency of the c.115T allele of 0,9 % in Brazil (Andrade 2020). Outside that series: limited data.

- Persistent proteinuria from a young age\n- Progression to chronic renal failure\n- Thickening and splitting of the glomerular basement membrane (biopsy)\n- Juvenile presentation and progressive course, usually fatal

Davidson et al. (2007) identified a substitution at base 115 with a premature stop codon in exon 3 of COL4A4, segregating with the clinical status in all affected English Cockers and obligate carriers. Nowend et al. (2012) described a different variant of the same gene in the English Springer Spaniel (c.2806). Andrade et al. (2020) estimated the frequency of the c.115T allele at 0,9 % in English Cockers from Brazil.

- Test the breeding animals before mating.\n- Do not cross two carriers: 25 %% risk of affected homozygotes; carrier×clear with tested offspring.\n- In the face of persistent juvenile proteinuria, include FN in the differential diagnosis and confirm by molecular test.\n- Record the status in the pedigree.

Differential diagnosis: other juvenile glomerulopathies and chronic pyelonephritis. Renal biopsy (basement membrane) guides; the molecular test confirms. No curative treatment.

1. Davidson MG et al. 2007, causa genética de la nefropatía hereditaria autosómica recesiva del Cocker spaniel inglés (PMID 17552442)
2. Nowend KL et al. 2012, base genética de la ARHN en Springer spaniel inglés (PMID 22369189)
3. Andrade et al. 2020, frecuencia del alelo en Cockers ingleses de Brasil (PMID 32734115)
4. OMIA:002618 Nefropatía (COL4A4)