Krabbe’s disease in two West Higland White Terriers

Two 3-month-old male West Highland White Terriers were referred for progressive neurological disease. Histological examination of the central nervous system of the animals euthanized at the owner request, revealed diffuse, bilateral and symmetrical white matter lesion consisting of varying degrees of demyelination and axonal degeneration. Accumulation of round to ovoid large mononuclear cells were especially observed along the blood vessels in the white matter. These cells were characterized by central or eccentric nuclei and highly eosinophilic, granular, PAS positive cytoplasm. Stored material was stained with toluidine blue both at pH 4 and pH 11 and exhibit a strong PAC and no PALK activities. Staining for lectins revealed a positivity using Ricinus communis agglutinin-I, Ricinus communis agglutin-II, Triticum vulgaris, and Concavalin A. Histochemical evaluation of intracellular material were performed on the kidney and on the liver too. Ultrastructural investigations allowed to observe the cytoplasmatic contents of globoid cells that is an admixture of degraded myelin membranes and different kind of tubular aggregates. To verify if the two dogs bore the mutation at position 473, a method involving PCR amplification of genomic DNA followed by restriction digestion was used. Based on clinical evaluation, morphological, histochemical and ultrastructural features the diagnosis of Krabbe’s disease was performed.