Abnormal Morphology of Distal Tubular Epithelial Cells Is Regulated by Genetic Factors Derived from Mouse Chromosome 12.

The distal tubule (DT) helps regulate blood pressure and electrolytes. We describe a novel, autosomal recessive, morphofunctional DT abnormality in inbred mice evident as columnar alternations and age-related cystic changes. This abnormality developed in both sexes of DBA/2Cr. Similar phenotypes were observed in A/J, C3H/He, DBA/1J, and FVB/N strains, but not in AKR/N, BALB/c, or C57BL/6N strains. In DBA/2Cr, abnormal DT localized to straight and convoluted segments and showed IL-36α DT injury marker expression. However, DT epithelial proliferation, examined by bromodeoxyuridine incorporation, was not remarkably altered with the progression of abnormality. Abnormal DT epithelial cells in DBA/2Cr displayed elongated primary cilia, loose intercellular adhesions, and numerous vesicles with altered localization of CD9, Na+/K+ATPase, and E-cadherin, indicating altered cell function, adhesion, and polarity. DBA/2Cr-type D12Mit182-D12Mit83 was identified as a candidate locus designated DBA/2 renal cyst (drecy). Within drecy, the gene regulated by estrogen in breast cancer protein (Greb1) transcript variant 2 was significantly up-regulated in DBA/2Cr kidney versus C57BL/6N. Greb1 localized to DT cytoplasm in C57BL/6 and to cytoplasm and nucleus in DBA/2Cr. Greb1-overexpressing M-1 kidney cells showed an altered epithelial-mesenchyme phenotype. B6.D2-(D12Mit182-D12Mit83) congenic mice carrying drecy did not show DT abnormalities, whereas DBA/2Cr × B6.D2-(D12Mit182-D12Mit83) mice did. Identification of this novel DT abnormality regulated by a DBA/2Cr mouse chromosome 12-derived locus and additional genetic factors improve the understanding of DT pathogenesis.

Safety and efficacy of aged garlic extract in dogs: upregulation of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and Nrf2-regulated phase II antioxidant enzymes.

BACKGROUND: Plants of Allium spp., including garlic (A. sativum) and onions (A. cepa), are known to be oxidatively toxic to canine erythrocytes resulting in Heinz body hemolytic anemia in dogs. In humans, these plants have been used as medicinal agents for multiple diseases since ancient times. Especially, fresh garlic extracted over a prolonged period produces less irritative and odorless aged garlic extract (AGE), containing unique and beneficial organosulfur compounds that can help prevent many kinds of diseases. In this study, the safety and efficacy of long-term oral administration of AGE is evaluated in dogs. The objectives are to confirm the safe dosage for long-term use and beneficial functions of AGE for dogs and to plan and design a canine health supplement or a preventive agent for multiple diseases based on the data of this study. RESULTS: Beagles were orally administered AGE (45 or 90 mg/kg body weight once a day) or an equivalent amount of water as control for 12 weeks. In AGE-treated groups, at 12 weeks post-administration at a dose of 90 mg/kg, there were no observable changes in the clinical signs, complete blood count, and serum biochemical parameters. Heinz bodies and eccentrocytes, the markers of oxidative damage in erythrocytes, did not appear in blood smear examination. In order to further evaluate the beneficial effects of AGE on health of dogs, the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) gene (NFE2L2) and Nrf2-regulated phase II antioxidant enzyme genes (NQO1, GCLM, HMOX1, and SOD2) were determined in whole blood between pre- and post-AGE administration. The expression of NFE2L2 gene was significantly upregulated in the AGE-treated groups [45 (p < 0.05) and 90 mg/kg (p < 0.01), 8 weeks] as compared to in the control group. Among the Nrf2-regulated enzymes examined, the expressions of NQO1 [45 (p < 0.05) and 90 mg/kg (p < 0.01), 8 weeks] and GCLM [45 (p < 0.05) and 90 mg/kg (p < 0.01), 12 weeks] genes were significantly upregulated. CONCLUSION: The long-term oral administration of AGE at a dose of 90 mg/kg/day for 12 weeks did not show any adverse effects in dogs. Furthermore, the administration of AGE upregulated the gene expressions of canine Nrf2 and Nrf2-regulated phase II antioxidant enzymes. These results suggest that AGE might safely contribute to the health of dogs provided that the appropriate dosage is used.

Paraffin immunofluorescence for detection of immune complexes in renal biopsies: an efficient salvage technique for diagnosis of glomerulonephritis in dogs.

BACKGROUND: Renal biopsy is an essential tool for the diagnosis of proteinuric kidney diseases in dogs, and evaluation of immune complexes (IC) by immunofluorescence (IF) of frozen sections (IF-F) is required for the diagnosis of IC-mediated glomerulonephritis (ICGN). However, the use of frozen sections from renal biopsies can have limitations. The aim of this study was to develop a reliable IF method using formalin-fixed and paraffin-embedded (FFPE) sections to detect ICs in dog ICGN. METHODS: Renal biopsy specimens were obtained from dogs with protein-losing nephropathies. FFPE sections were prepared, and eight antigen retrieval pretreatment protocols were performed: digestion with trypsin, microwave (MW) heating in citrate buffer (MW-CB; pH 6.0), MW heating in Tris-EDTA buffer (MW-TEB; pH 9.0), as well as combinations of the above, and a non-treated control. RESULTS: A combination of trypsin for 30 min (Try-30) and MW-TEB; pH 9.0 was the most effective antigen retrieval pretreatment, with clear positive signals for IgG, IgA, IgM, and C3 detected by IF-FFPE. Granular signals, an important diagnostic indicator of ICGN, were clearly observed by both IF-F and IF-FFPE after combined pretreatment with Try-30 and MW-TEB, and IgG, IgA, IgM, and C3 signals were almost completely matched in all samples by IF-F and IF-FFPE. CONCLUSION: IF-FFPE with Try-30 and MW-TEB pretreatment is a valuable technique for the diagnosis of renal diseases in dogs. This method could be an efficient tool when standard IF-F cannot be used, or does not provide useful results due to lack of glomeruli in the specimens for IF-F.

In situ detection of GM1 and GM2 gangliosides using immunohistochemical and immunofluorescent techniques for auxiliary diagnosis of canine and feline gangliosidoses.

BACKGROUND: GM1 and GM2 gangliosidoses are progressive neurodegenerative lysosomal storage diseases resulting from the excessive accumulation of GM1 and GM2 gangliosides in the lysosomes, respectively. The diagnosis of gangliosidosis is carried out based on comprehensive findings using various types of specimens for histological, ultrastructural, biochemical and genetic analyses. Therefore, the partial absence or lack of specimens might have resulted in many undiagnosed cases. The aim of the present study was to establish immunohistochemical and immunofluorescent techniques for the auxiliary diagnosis of canine and feline gangliosidoses, using paraffin-embedded brain specimens stored for a long period. RESULTS: Using hematoxylin and eosin staining, cytoplasmic accumulation of pale to eosinophilic granular materials in swollen neurons was observed in animals previously diagnosed with GM1 or GM2 gangliosidosis. The immunohistochemical and immunofluorescent techniques developed in this study clearly demonstrated the accumulated material to be either GM1 or GM2 ganglioside. CONCLUSIONS: Immunohistochemical and immunofluorescent techniques using stored paraffin-embedded brain specimens are useful for the retrospective diagnosis of GM1 and GM2 gangliosidoses in dogs and cats.

Severe glomerular fibrin thrombosis in a dog.

Here, we present a case of severe glomerular fibrin thrombosis in a dog with lymphoma. A 3-year-old neutered male Chihuahua presented with acute kidney injury, hypoalbuminemia, and transudate ascites. The dog showed symmetric enlargement of the spleen, which was diagnosed as B-cell lymphoma based on cytology and polymerase chain reaction tests. The dog died after intensive care, and the kidneys were removed for histopathological examination. Light microscopy, immunofluorescence, and electron microscopy analyses were performed for renal pathology; however, the findings did not support the evidence of protein-losing nephropathy. Instead, the endocapillary accumulation of fibrin thrombi was prominent in most glomeruli. A diagnosis of severe glomerular fibrin thrombosis was established, and hypoalbuminemia was considered the underlying cause of kidney damage.

Cabot rings in a cat with myeloproliferative disease.

A 6-year-old spayed female Scottish Fold cat presented with lethargy and anorexia. A complete blood cell count indicated severe anemia and mild thrombocytopenia. Examination of peripheral blood smears revealed marked changes in the erythroid lineage, including the presence of basophilic stippling and Howell-Jolly bodies as well as an increase in nucleated erythrocytes, polychromatophils, ovalocytes, and schistocytes. Additionally, some erythrocytes contained a ring or figure-eight shaped structure known as a Cabot ring, which were especially observed in polychromatophilic erythrocytes. Hemolytic diseases (Mycoplasma infection and IMHA) were diagnostically excluded, and the cat was treated through prednisolone administration, whole blood transfusion, and administration of vitamins (K2 and B12); however, the anemia progressively worsened. Cabot rings were observed until Day 22 and subsequently disappeared as the number of nucleated RBCs increased, and the erythrocyte lineage shifted to immature population. On Day 42, peripheral blood examination revealed further left shifting and appearance of many rubriblasts. The patient died at home on Day 43. Necropsy revealed neoplastic cells infiltrating the bone marrow and other organs, which were immunopositive to CD71 which is an erythroid lineage marker. In humans, Cabot rings have been observed in megaloblastic anemia, lead poisoning, myelodysplastic syndrome, and myelofibrosis; further, they are thought to be related to stressed bone marrow and dyserythropoiesis. This is the first case report of a cat with Cabot rings, which are suggestive of defects in erythroid lineage production.

Molecular epidemiology of canine GM1 gangliosidosis in the Shiba Inu breed in Japan: relationship between regional prevalence and carrier frequency.

BACKGROUND: Canine GM1 gangliosidosis is a fatal disease in the Shiba Inu breed, which is one of the most popular traditional breeds in Japan and is maintained as a standard breed in many countries. Therefore, it is important to control and reduce the prevalence of GM1 gangliosidosis for maintaining the quality of this breed and to ensure supply of healthy dogs to prospective breeders and owners. This molecular epidemiological survey was performed to formulate an effective strategy for the control and prevention of this disease. RESULTS: The survey was carried out among 590 clinically unaffected Shiba Inu dogs from the 8 districts of Japan, and a genotyping test was used to determine nation-wide and regional carrier frequencies. The number and native district of affected dogs identified in 16 years from 1997 to June 2013 were also surveyed retrospectively. Of the 590 dogs examined, 6 dogs (1.02%, 6/590) were carriers: 3 dogs (2.27%, 3/132) from the Kinki district and the other 3 dogs from the Hokkaido, Kanto, and Shikoku districts. The retrospective survey revealed 23 affected dogs, among which, 19 dogs (82.6%) were born within the last 7 years. Of the 23 affected dogs, 12 dogs (52.2%) were from the Kinki district. Pedigree analysis demonstrated that all the affected dogs and carriers with the pedigree information have a close blood relationship. CONCLUSIONS: Our results showed that the current carrier frequency for GM1 gangliosidosis is on the average 1.02% in Japan and rather high in the Kinki district, which may be related to the high prevalence observed over the past 16 years in this region. This observation suggests that carrier dogs are distributed all over Japan; however, kennels in the Kinki district may face an increased risk of GM1 gangliosidosis. Therefore, for effective control and prevention of this disease, it is necessary to examine as many breeding dogs as possible from all regions of Japan, especially from kennels located in areas with high prevalence and carrier frequency.

Usefulness and Limitations of Cryopreservation for Immunocytochemical Staining of Canine Cytological Specimens for Detection of Cytokeratin and Vimentin.

Immunocytochemistry is an advanced diagnostic tool for identifying the origin of tumor cells. This study aimed to highlight the usefulness of cryopreserved, air-dried cytological samples in detecting cytokeratin and vimentin. Air-dried cytological smear samples were prepared from a total of 39 resected canine tumors and stored in a medical freezer without fixation. The duration of cryopreservation ranged from 2 to 56 months. The same tumors were processed for routine histopathological examination. Based on the morphological diagnosis, cryopreserved FNA smears from epithelial tumors were stained by enzymatic immunocytochemistry (ICC) for cytokeratin; those from mesenchymal and melanocytic tumors were stained by ICC for vimentin. To ascertain the positivity of tumor cells to the selected markers, tissue paraffin-embedded sections were also stained by immunohistochemistry (IHC) for the same markers. Immunoreactivity for cytokeratin was detected in cryopreserved cytological smears for a maximum of 46 months. Immunoreactivity for vimentin was clearly detected for 33 months. Smears stored at room temperature for 1 week did not show any signals under immunocytochemical examination. Thus, immunocytochemistry for cytokeratin and vimentin can be safely applied to air-dried smears cryopreserved in a freezer for at least 33 months.

Immunohistochemical analysis of renal oxidative damage in senior and geriatric cats with chronic kidney disease.

Oxidative stress is a well-known cause of chronic kidney disease (CKD). In this study, renal oxidative damage in azotaemic and non-azotaemic aged cats with naturally occurring CKD was investigated using immunohistochemistry for 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE) as markers of oxidative tissue damage. Kidneys were obtained from aged (>10 years old) azotaemic (n = 13) and non-azotaemic (n = 7) cats. Immunoreactivity for 8-OHdG was found in the nuclei of glomeruli, proximal and distal tubules, loops of Henle and collecting ducts, whereas 4-HNE-positive signals were detected in the cytoplasm of distal nephrons in azotaemic and non-azotaemic cats. Quantitative analysis did not identify any significant differences between the azotaemic and non-azotaemic groups for any of the parameters examined. These results indicate that renal oxidative damage occurs in the kidneys of aged cats with CKD, regardless of whether they are azotaemic or non-azotaemic, emphasizing the importance of oxidative stress during early-stage CKD in senior and geriatric cats.

Novel Mutation in the Feline GAA Gene in a Cat with Glycogen Storage Disease Type II (Pompe Disease).

Glycogen storage disease type II (Pompe disease: PD) is an autosomal recessively inherited fatal genetic disorder that results from the deficiency of a glycogen hydrolyzing enzyme, acid α-glucosidase encoded by the GAA gene. Here, we describe the molecular basis of genetic defects in an 8-month-old domestic short-haired cat with PD. The cat was previously diagnosed with PD based on the clinical and pathological findings of hypertrophic cardiomyopathy and excessive accumulation of glycogen in the cardiac muscles. Sanger sequencing was performed on 20 exons of the feline GAA gene using genomic DNA extracted from paraffin-embedded liver tissues. The affected cat was found to be homozygous for the GAA:c.1799G>A mutation resulting in an amino acid substitution (p.R600H) of acid α-glucosidase, a codon position of which is identical with three missense mutations (p.R600C, p.R600L, and p.R600H) causing human infantile-onset PD (IOPD). Several stability and pathogenicity predictors have also shown that the feline mutation is deleterious and severely decreases the stability of the GAA protein. The clinical, pathological, and molecular findings in the cat were similar to those of IOPD in humans. To our knowledge, this is the first report of a pathogenic mutation in a cat. Feline PD is an excellent model for human PD, especially IOPD.

Therapeutic effect of aged garlic extract on gingivitis in dogs.

Periodontal disease is one of the most common dental health problems in dogs. Clinical studies in humans have shown that aged garlic extract (AGE), which contains stable and water-soluble sulfur-containing bioactive compounds, improves the symptoms of periodontal diseases. Our previous study demonstrated that oral administration of AGE in healthy Beagle dogs at 90 mg/kg/day for 12 weeks had no adverse effects such as hemolytic anemia, which is well known to occur as a result of ingestion of Allium species, including onions and garlic, in dogs. However, the therapeutic potential of AGE in canine periodontal disease remains unclear. Accordingly, we investigated the therapeutic effects of AGE in Beagle dogs with mild gingivitis. Feeding 18 mg/kg/day of AGE for 8 weeks resulted in the improvement of gingival index score, level of volatile sulfur compounds in exhaled air, and enzyme activity of periodontal pathogens without any adverse effects on clinical signs and hematological and serum biochemical parameters. Moreover, AGE increased the concentration of salivary cathelicidin, an antimicrobial peptide that contributes to the oral innate immune response. These results suggest that AGE could be a potential therapeutic agent for canine gingivitis.

Novel Mutation in the Feline NPC2 Gene in Cats with Niemann-Pick Disease.

Niemann-Pick disease (NP) type C is an autosomal, recessive, and inherited neurovisceral genetic disorder characterized by the accumulation of unesterified cholesterol and glycolipids in cellular lysosomes and late endosomes, with a wide spectrum of clinical phenotypes. This study aimed to determine the molecular genetic alterations in two cases of felines with NP in Japan, a Siamese cat in 1989 and a Japanese domestic (JD) cat in 1998. Sanger sequencing was performed on 25 exons of the feline NPC1 gene and 4 exons of the feline NPC2 gene, using genomic DNA extracted from paraffin-embedded tissue specimens. The sequenced exons were compared with reference sequences retrieved from the GenBank database. The identified mutations and alterations were then analyzed using different prediction algorithms. No pathogenic mutations were found in feline NPC1; however, c.376G>A (p.V126M) was identified as a pathogenic mutation in the NPC2 gene. The Siamese cat was found to be homozygous for this mutation. The JD cat was heterozygous for the same mutation, but no other exonic NPC2 mutation was found. Furthermore, the JD cat had a homozygous splice variant (c.364-4C>T) in the NPC2 gene, which is not known to be associated with this disease. The NPC2:c.376G>A (p.V126M) mutation is the second reported pathogenic mutation in the feline NPC2 gene that may be present in the Japanese cat population.

Collie eye anomaly in Hokkaido dogs: case study.

OBJECTIVE: To describe a Hokkaido dog, one of the traditional Japanese breeds that was affected by Collie eye anomaly (CEA), and to report the genotype of this dog and the Hokkaido dog allelic frequency of the CEA-associated mutation. CASE: A nine-month-old intact female Hokkaido dog without any obvious visual disturbance was diagnosed ophthalmoscopically with CEA. Severe choroidal hypoplasia was observed in the bilateral temporal area adjacent to the optic nerve head, appearing as whitish areas. Therefore, the dog was suspected of possessing the CEA-associated mutation that was previously reported as an intronic 7.8-kilo base deletion in the canine NHEJ1 gene. PROCEDURES: SYBR Green-based real-time PCR with a melting curve analysis, conventional PCR with agarose gel electrophoresis, and direct DNA sequencing were carried out to determine the genotype of the dog. Furthermore, a preliminary genotyping survey was carried out in 17 Hokkaido dogs from three kennels using the real-time PCR method, and the pedigree relationships were analyzed using their pedigree papers. RESULTS: The Hokkaido dog affected by CEA was proven to possess the CEA-associated mutation. Of these 17 Hokkaido dogs, 12 dogs were heterozygous carriers and five dogs were affected by this mutation. The preliminary genotyping survey and pedigree analysis demonstrated that the allelic frequency of the CEA-associated mutation is very high in Hokkaido dogs. CONCLUSION: These data suggest that the Hokkaido breed is highly susceptible to CEA because of the known CEA-associated mutation much like the Collie-related breeds.

Radioprotective effect of alk(en)yl thiosulfates derived from allium vegetables against DNA damage caused by X-ray irradiation in cultured cells: antiradiation potential of onions and garlic.

To evaluate a radioprotective effect of sodium n-propyl thiosulfate (NPTS) and sodium 2-propenyl thiosulfate (2PTS) derived from onions and garlic, respectively, rat hepatoma H4IIE cells and mouse lymphoma L5178Y cells were preincubated with each of these compounds for 48 hours at 37°C before receiving 10 Gy of X-ray irradiation. Cell damage caused by the irradiation was quantified as comet tail moment, which represents the degree of DNA damage. X-ray-induced DNA damage was significantly decreased in both H4IIE and L5178Y cells by micromolar concentrations of NPTS and 2PTS compared with the control without the compounds. The protective effect was more potent with 2PTS than NPTS. Onions and garlic have antiradiation potential.

Serial MRI features of canine GM1 gangliosidosis: a possible imaging biomarker for diagnosis and progression of the disease.

GM1 gangliosidosis is a fatal neurodegenerative lysosomal storage disease caused by an autosomal recessively inherited deficiency of ß-galactosidase activity. Effective therapies need to be developed to treat the disease. In Shiba Inu dogs, one of the canine GM1 gangliosidosis models, neurological signs of the disease, including ataxia, start at approximately 5 months of age and progress until the terminal stage at 12 to 15 months of age. In the present study, serial MR images were taken of an affected dog from a model colony of GM1 gangliosidosis and 4 sporadic clinical cases demonstrating the same mutation in order to characterize the MRI features of this canine GM1 gangliosidosis. By 2 months of age at the latest and persisting until the terminal stage of the disease, the MR findings consistently displayed diffuse hyperintensity in the white matter of the entire cerebrum on T2-weighted images. In addition, brain atrophy manifested at 9 months of age and progressed thereafter. Although a definitive diagnosis depends on biochemical and genetic analyses, these MR characteristics could serve as a diagnostic marker in suspect animals with or without neurological signs. Furthermore, serial changes in MR images could be used as a biomarker to noninvasively monitor the efficacy of newly developed therapeutic strategies.

Neuronal ceroid lipofuscinosis in Border Collie dogs in Japan: clinical and molecular epidemiological study (2000-2011).

Neuronal ceroid lipofuscinosis (NCL) is an inherited, neurodegenerative lysosomal disease that causes premature death. The present study describes the clinical and molecular epidemiologic findings of NCL in Border Collies in Japan for 12 years, between 2000 and 2011. The number of affected dogs was surveyed, and their clinical characteristics were analyzed. In 4 kennels with affected dogs, the dogs were genotyped. The genetic relationships of all affected dogs and carriers identified were analyzed. The survey revealed 27 affected dogs, but there was a decreasing trend at the end of the study period. The clinical characteristics of these affected dogs were updated in detail. The genotyping survey demonstrated a high mutant allele frequency in examined kennels (34.8%). The pedigree analysis demonstrated that all affected dogs and carriers in Japan are related to some presumptive carriers imported from Oceania and having a common ancestor. The current high prevalence in Japan might be due to an overuse of these carriers by breeders without any knowledge of the disease. For NCL control and prevention, it is necessary to examine all breeding dogs, especially in kennels with a high prevalence. Such endeavors will reduce NCL prevalence and may already be contributing to the recent decreasing trend in Japan.

Lectin Histochemistry of the Normal Feline Kidney.

Lectins have a strict binding specificity to carbohydrate moieties of cellular components, and can thus indicate changes in the glycosylation of cells in diseases. However, lectin-binding patterns in nephron segments of feline kidneys have not been fully surveyed. The present study reported lectin-binding patterns in normal feline kidneys by histochemical investigations of eight commercially available lectin detection kits. Kidneys from four normal cats (intact males, 23-27 months old) were fixed in 4% paraformaldehyde, and embedded in paraffin; lectin histochemistry was performed for WGA, s-WGA, RCA-I, ConA, PNA, SBA, DBA, and UEA-I lectins. WGA, RCA, and ConA binding was observed from Bowman's capsule to the collecting ducts, while only WGA was detected in the glomerular capillary. s-WGA was observed from the proximal tubules to the collecting ducts, showing discriminative heterogeneous binding. PNA and SBA were detected in the distal nephrons, such as the thin limbs of the loops of Henle, distal tubules, and collecting ducts. UEA-I binding was observed in the thick ascending limbs of the loops of Henle, especially in the macula densa regions. DBA lectin showed no positive labeling in nephrons. The observed binding patterns may prove beneficial for the analysis of changes in glycosylation in feline kidney diseases.

Immunohistochemical Expression of TGF-ß1 in Kidneys of Cats with Chronic Kidney Disease.

Transforming growth factor-beta 1 (TGF-ß1) plays a central role in the progression of chronic kidney disease (CKD). However, in feline CKD, renal expression of TGF-ß1 and how it changes as the disease progresses have not been fully studied. In the present study, we immunohistochemically assessed the renal expression levels of TGF-ß1 in cats with CKD and statistically analyzed its correlation with CKD severity. Clear immunosignals were detected in the glomerular mesangial cells, Bowman's capsules, proximal tubules, distal nephrons, platelets, and vascular smooth muscles in the kidneys of cats with CKD. Statistically, luminal signals in the distal nephrons showed positive correlations with plasma creatinine levels and glomerulosclerosis, while those in the proximal tubules and platelets showed negative correlations with plasma urea and/or creatinine levels. Therefore, it was suggested that the changes in the renal expression of TGF-ß1 could be associated with progression of feline CKD.

Glycogen storage disease in a young cat with heart failure.

An 8-month-old domestic short-haired female cat presented with acute tachypnea, poor growth, hypothermia, and lethargy. Thoracic radiography showed cardiomegaly with mild pleural effusion, and transthoracic echocardiography identified dilatation of both atria and left ventricular systolic dysfunction. Although clinical signs improved temporarily with treatment, the cat died of pulmonary edema 135 days after the first visit. At necropsy, the heart was grossly enlarged. Microscopic examination of the heart identified severe vacuolization of cardiac muscle cells in histologic sections stained with hematoxylin and eosin. Examination of periodic acid-Schiff stained preparations of formalin-fixed heart tissue disclosed coarse granules within vacuoles that disappeared on predigestion with diastase, indicating that they were glycogen. On the basis of these findings, a necropsy diagnosis of glycogen storage disease type II (Pompe disease) was made. This report is the first case of a young cat with clinical signs closely resembling infantile Pompe disease of humans.

Carrier Rate and Mutant Allele Frequency of GM1 Gangliosidosis in Miniature Shiba Inus (Mame Shiba): Population Screening of Breeding Dogs in Japan.

GM1 gangliosidosis is a progressive, recessive, autosomal, neurodegenerative, lysosomal storage disorder that affects the brain and multiple systemic organs due to an acid ß-galactosidase deficiency encoded by the GLB1 gene. This disease occurs in the Shiba Inu breed, which is one of the most popular traditional breeds in Japan, due to the GLB1:c.1649delC (p.P550Rfs*50) mutation. Previous surveys performed of the Shiba Inu population in Japan found a carrier rate of 1.02-2.94%. Currently, a miniature type of the Shiba Inu called "Mame Shiba", bred via artificial selection to yield smaller individuals, is becoming more popular than the standard Shiba Inu and it is now one of the most popular breeds in Japan and China. The GM1 gangliosidosis mutation has yet to be surveyed in the Mame Shiba population. This study aimed to determine the frequency of the mutant allele and carrier rate of GM1 gangliosidosis in the Mame Shiba breed. Blood samples were collected from 1832 clinically healthy adult Mame Shiba Inus used for breeding across 143 Japanese kennels. The genotyping was performed using a real-time PCR assay. The survey found nine carriers among the Mame Shibas, indicating that the carrier rate and mutant allele frequency were 0.49% and 0.00246, respectively. This study demonstrated that the mutant allele has already been inherited by the Mame Shiba population. There is a risk of GM1 gangliosidosis occurrence in the Mame Shiba breed if breeders use carriers for mating. Further genotyping surveys are necessary for breeding Mame Shibas to prevent the inheritance of this disease.