Dogs In Korea Research Articles

Continuing Evolution and Interspecies Transmission of Influenza Viruses in Live Bird Markets in Korea

Live bird markets (LBMs) provide an ideal environment for the evolution and interspecies transfer of avian influenza viruses (AIVs). In this study, we analyzed AIVs present in LBMs in Korea during the winter seasons of 2006-08. Sixty-five AIVs that belong to four hemagglutination (HA) subtypes ofAIV (H3, H4, H6, and H9) were isolated from 644 pooled tissue or swab samples collected in LBMs. Most H9 subtypes of AIVs were isolated from Galliformes (chickens, silky fowls, pheasants, and guinea fowls), and other subtypes were isolated from Anseriformes (Pekin ducks and mallards). In addition, we obtained a single H3N2 virus from nasal swabs of dogs sold in LBMs, and the virus was genetically identical to the canine influenza virus (CIV) isolated from pet dogs in Korea. Phylogenetic analysis suggests that the Korean H9N2 viruses prevalent in chickens have provided their gene segments to AIVs circulating in ducks. These gene transfers facilitated reassortment events among AIVs and likely generated the ancestors of CIV in Korea. An animal challenge study using chickens, quail, mice, and dogs had shown that the H4 and H6 subtypes could replicate in mice and that some H4 and H6 viruses could replicate in chickens without preadaptation. In addition, two H3 subtype viruses (H3N2 and H3N8) induced interstitial pneumonia that accompanied clinical signs and seroconversion in dogs. Our findings indicate that the newly evolved AIVs have been continuously generated by reassortment in ducks, and these reassortments could result in expanding the host range of AIVs.

A Serological Survey of Canine Respiratory Coronavirus and Canine Influenza Virus in Korean Dogs

The relationship between canine respiratory coronavirus (CRCoV) and canine influenza virus (CIV) seropositivity in dogs in Korea was examined. Sixty-two of the 483 samples (12.8%) were seropositive for CRCoV by indirect fluorescent antibody (IFA) analysis. Nineteen animals were seropositive for CIV by ELISA out of the 385 samples tested. Serum antibodies for both viruses were detected in 6 of the 483 dogs sampled, suggesting that these viruses are present in dogs in Korea. Although the role of CRCoV in canine infectious tracheobronchitis has not been fully elucidated, co-infection with CIV may synergistically worsen respiratory clinical signs and result in more severe canine tracheobronchitis.

Characterization of canine oral papillomavirus by histopathological and genetic analysis in Korea

In August 2008, forty dogs out of 400 developed oral warts in a breeding farm in Korea. Canine oral papilloma infection is a common disease in dogs. However, there has been no report of an outbreak of canine oral papillomavirus (COPV) in a group of dogs or in dog breeding farms in Korea, and the genetic analysis of COPV in Korea has yet to be performed. This study diagnosed canine oral papilloma from the oral samples of these dogs based on histopathological examination and immunohistochemistry. Polymerase chain reaction was applied to amplify the corresponding products using pre-existing primer sets for COPV and a universal human papillomavirus targeting L1 gene. Further genetic analysis of the major viral capsid gene L1 confirms the sequences of Korean COPV, which shows a close relationship to previously reported COPV. This study describes the histopathological and immunohistochemical characteristics of canine oral papilloma in a group of breeding dogs in Korea and discloses the complete L1 gene sequences of Korean COPV.

Retrospective Study of Melamine/Cyanuric Acid-Induced Renal Failure in Dogs in Korea between 2003 and 2004

In early 2007, American pet food ingredients leading to nephrotoxic renal failure of dogs and cats raised serious concerns about the safety of pet foods. Major pet food companies recalled more than 1,000 commercial pet foods in consideration of pet safety. A similar pet food-associated outbreak of nephrotoxic renal failure occurred in Asia, in late 2003 and 2004, resulting in a similar extensive pet food recall. At that time, contamination of ingredients with a nephrotoxin-producing fungus at a pet food production facility was suspected. However, toxicologic evidence to substantiate a mycotoxicosis was lacking. Moreover, the renal lesions were not typical of those reported with fungal nephrotoxins. During 2003 and 2004, 14 dogs were presented to the Veterinary Medical Teaching Hospital of Konkuk University, Seoul, Korea, with renal failure and distinctive renal pathologic findings. Grossly, the kidneys were greenish in color with greenish uroliths in the renal pelvis or bladder. Histologically, characteristic crystals with pinwheel radiating striations were present in distal tubular segments. Toxicologic analysis identified melamine, cyanuric acid, and ammelide in deparaffinized formalin-fixed kidney samples.

A serological survey of avian origin canine H3N2 influenza virus in dogs in Korea

Canine H3N2 influenza viruses of avian origin were recently isolated and found to induce disease in dogs. Results of serologic analysis indicate that avian origin canine influenza virus can spread rapidly through local dog populations, which indicates its potential for becoming established in dogs throughout Korea.

Retrospective Study of Melamine/Cyanuric Acid-Induced Renal Failure in Dogs in Korea between 2003 and 2004

In early 2007, American pet food ingredients leading to nephrotoxic renal failure of dogs and cats raised serious concerns about the safety of pet foods. Major pet food companies recalled more than 1,000 commercial pet foods in consideration of pet safety. A similar pet food-associated outbreak of nephrotoxic renal failure occurred in Asia, in late 2003 and 2004, resulting in a similar extensive pet food recall. At that time, contamination of ingredients with a nephrotoxin-producing fungus at a pet food production facility was suspected. However, toxicologic evidence to substantiate a mycotoxicosis was lacking. Moreover, the renal lesions were not typical of those reported with fungal nephrotoxins. During 2003 and 2004, 14 dogs were presented to the Veterinary Medical Teaching Hospital of Konkuk University, Seoul, Korea, with renal failure and distinctive renal pathologic findings. Grossly, the kidneys were greenish in color with greenish uroliths in the renal pelvis or bladder. Histologically, characteristic crystals with pinwheel radiating striations were present in distal tubular segments. Toxicologic analysis identified melamine, cyanuric acid, and ammelide in deparaffinized formalin-fixed kidney samples.

A suspected case of Lyme borreliosis in a hunting dog in Korea

A two-year-old male Pointer had been presented with anorexia, cachexia, and weight loss of 10-day duration. Upon physical examination, fever, lethargy, superficial lymph node enlargement, and tick infestation were noted. The only abnormality in CBC and serum chemistry analyses was mild hyperglobulinemia. Spleen was enlarged by radiography, and the lymph nodes showed neutrophilic lymphadenitis by cytological examination. A polymerase chain reaction test for babesiosis and commercial ELISA tests for Ehrlichia canis, heartworm, and Lyme disease was negative except for Lyme disease, which was verified by both an IFA-IgG test and a quantitative C6 assay. Doxycycline was administered for 2 weeks and the recovery was uneventful. Post-treatment C6 titer decreased to within normal limits.

Prevalence of Bartonella henselae and Bartonella clarridgeiae in cats and dogs in Korea

Blood, saliva, and nail samples were collected from 54 dogs and 151 cats and analyzed for the presence of Bartonella henselae with a novel nested polymerase chain reaction (PCR) method. Bartonella (B.) henselae was detected in feral cat blood (41.8%), saliva (44.1%), and nail (42.7%) samples. B. henselae was also detected in pet cat blood (33.3%), saliva (43.5%), and nail (29.5%) samples and in pet dog blood (16.6%), saliva (18.5%), and nail (29.6%) samples. Nine samples were infected with B. clarridgeiae and 2 were co-infected with B. henselae and B. clarridgeiae of blood samples of dogs. This report is the first to investigate the prevalence of B. henselae and B. clarridgeiae in dogs and cats in Korea, and suggests that dogs and cats may serve as potential Bartonella reservoirs.

Sarcoptic Mange in Wild Raccoon Dogs (Nyctereutes procyonoides) in Korea

Infestation with Sarcoptes scabiei was diagnosed from four wild raccoon dogs (Nyctereutes procyonoides) accidentally captured and presented to the Animal Health Center in Seoul Grand Park Zoo, Korea. Diagnosis was done by microscopic and histologic examination from skin lesions. Sarcoptes scabiei was the only species detected from the lesions and characterized by dorsoventrally flattened and round bodies, sucker-like pulvilli borne on long nonjointed pretarsi, triangular scales and spinelike setae on the dorsum, and three epimeres that are chitinous extensions of the coxae of the legs. In addition, infiltration of mast cells in the dermis was associated with infestation of the burrowing mite. This is the first report of sarcoptic mange in raccoon dogs in Korea. Because heavy infestation with S. scabiei was found in all of the captured wild raccoon dogs, further work is necessary to develop prophylactic interventions to prevent the spread of sarcoptic mange in free-living raccoon dogs in Korea.

Acute Fibrinosuppurative Hemorrhagic Pneumonia Caused by S. equi Subsp. Zooepidermidis in the Shelter Dogs in Korea

Acute Fibrinosuppurative Hemorrhagic Pneumonia Caused by S. equi Subsp. Zooepidermidis in the Shelter Dogs in Korea

The T963C mutation of TP53 gene does not participate in the clonal origin of canine TVT

In dogs, the canine transmissible venereal tumor (CTVT) is the only neoplasm which is not produced by neoplastic transformation of normal cells; the tumor is transmitted from the affected dog to healthy dogs by implantation of one or various clones of cancer cells. Thus, the CTVT of dogs analyzed in various countries reveals similar genetic characteristics and consequently CTVT is considered to have a clonal origin. The CTVTs obtained from dogs in Korea showed the T963C mutation on TP53 gene; this mutation was thought to be a molecular alteration which participates in the origin of the ancestral clone, CTVT. Nonetheless, this supposed mutation has not been identified in other studies which were carried out for the purpose of clarifying the clonal origin of CTVT. Thus we have considered it important to identify the role of the T963C mutation of the TP53 gene in the clonal origin of CTVT in dogs. Consequently the region which includes the mutation of the TP53 gene in twenty samples of CTVT obtained from various canine breeds was PCR amplified and afterwards its sequence of nucleotides was determined. We conclude that this mutation did not participate in the clonal origin of the tumor, but was acquired at a later stage.

Arthrostoma miyazakiense (Nematoda: Ancylostomatidae) infection in raccoon dogs of Korea and experimental transmission to dogs

Arthrostoma miyazakiense (Nematoda: Ancylostomatidae) is a hookworm species reported from the small intestines of raccoon dogs (Nyctereutes procyonoides) in Japan. Five Korean raccoon dogs (N. procyonoides koreensis) caught from 2002 to 2005 in Jeollanam-do (Province), a southeastern area of South Korea, contained helminth eggs belonging to 4 genera (roundworm, hookworm, whipworm, and Capillaria spp.) and cysts of Giardia sp. in their feces. Necropsy findings of 1 raccoon dog revealed a large number of adult hookworms in the duodenum. These hookworms were identified as Arthrostoma miyazakiense based on the 10 articulated plates observed in the buccal capsule and the presence of right-sided prevulval papillae. Eggs of A. miyazakiense were 60-65 x 35-40 micrometer (av. 62.5 x 35 micrometer), and were morphologically indistinguishable from those of Ancylostoma caninum. The eggs were cultured to infective 2nd stage larvae via charcoal culture, and 100 infective larvae were used to experimentally infect each of 3 mixed-bred puppies. All puppies harbored hookworm eggs in their feces on the 12th day after infection. This is the first report thus far concerning A. miyazakiense infections in raccoon dogs in Korea, and the first such report outside of Japan.

Characteristics of methicillin resistant Staphylococcus aureus isolated from chicken meat and hospitalized dogs in Korea and their epidemiological relatedness

Methicillin resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in human and veterinary hospitals. The isolation of MRSA from animals and foodstuffs has been reported with an increased incidence. However, methicillin (oxacillin) is not used in animal husbandry or in animal hospitals in Korea. In this study, three pre-MRSA and one silent mecA-carrying methicillin susceptible S. aureus (smMSSA) were isolated from retail chicken meat, and three MRSA were isolated from hospitalized dogs in Korea. The three pre-MRSA isolates were determined to have a staphylococcal cassette chromosome mec (SCC mec) type III, and the smMSSA isolate was not classified. The animal hospital isolates were found to contain SCC mec type II. Seven and 15 S. aureus isolated from hospitalized humans and bovine milk, respectively, were also examined in this study in order to determine the epidemiological origins of MRSA. Multilocus sequencing typing (MLST) revealed that the chicken meat and bovine milk isolates were closely related to the animal hospital isolates. The SCC mec characteristics and MLST analyses indicated the possibility of the human to animal transmission of MRSA. These results highlight the importance of identifying MRSA carriers as well as intercepting MRSA transmission because MRSA is becoming increasingly widespread without any plausible relationship with the use of methicillin (oxacillin).

Molecular detection of Bartonella henselae DNA from fleas obtained from dogs, Korea

Purpose:The purpose of this study was to investigate the presence of Bartonella henselae DNA, which is known as an etiologic agent of lymphadenitis, in fleas from dogs. Methods:The Bartonella henselae infection was investigated in 42 fleas from 22 dogs in Korea. By using seminested PCR targeting pap31 gene, B. henselae DNA was amplified from fleas. Results:B. henselae DNA was detected in seven fleas (7 of 42 fleas, 16.7 percent) from four dogs (4 of 22 dogs, 18.2 percent). To confirm these findings, we performed sequencing and identified the seven PCR products. Sequence analysis revealed that six sequences belonged to Huston-1 genogroup and one sequence to Marseille genogroup. Conclusion:These results may suggest that dogs could be an important source of B. henselae infection in children in Korea. This is the first report about the detection of B. henselae in fleas from dogs in Korea

Comparison of the Acid-phosphatase Staining and Polymerase Chain Reaction for Detection of Dirofilaria repens Infection in Dogs in Korea

This study was performed to compare acid-phosphatase staining with polymerase chain reaction (PCR) analysis for the diagnosis of Dirofilaria repens infection. The infection of D. repens was confirmed in Korean reared German shepherd dogs. Knott's tests were carried out for the detection of microfilaria in 543 Korean reared German shepherd dogs (255 females and 288 males). Eighty four of the 543 dogs (15.5%) showed microfilaria-positive reactions with the modified Knott's test, and the test-positive microfilariae were then examined by both acid phosphatase staining and PCR analysis. Six (7.1%) and 17 (20.2%) of the 84 microfilaria-positive samples, by the Knott's tests were positive to D. repens by acid-phosphatase staining and in D. repens-specific PCR analysis, respectively. All samples found to be positive by the acid-phosphatase staining were also found to be positive by PCR analysis. Therefore, we conclude that PCR analysis (20.2%) is more valuable for the diagnosis of D. repens infection than acid-phosphatase staining (7.1%) (p<0.001).

Seroprevalence of antibodies to Neospora caninum in dogs and raccoon dogs in Korea.

Neospora caninum is an important cause of abortion in cattle, and dogs are its only known definitive host. Its seroprevalence among domestic urban and rural dogs and feral raccoon dogs (Nyctereutes procyonoides koreensis) in Korea was studied by indirect fluorescent antibody test (IFAT) and by the neospora agglutination test (NAT), respectively. Antibodies to N. caninum were found in 8.3% of urban dogs and in 21.6% of dogs at dairy farms. Antibody titers ranged from 1:50 to 1:400. Antibodies to N. caninum were found in six (23%) of 26 raccoon dogs. However, the potential role of raccoon dogs as a source of horizontal transmission of bovine neosporosis needs further investigation. The results of this study suggest that there is a close relationship between N. caninum infection among dairy farm dogs and cattle in Korea. This study reports for the first time upon the seroprevalence of N. caninum infection in raccoon dogs in Korea.

Allergens Causing Atopic Diseases in Canine

Canine atopic skin disease is seasonal or sometimes non-seasonal immune-mediated skin disease which occurs commonly in Korea. The definite clinical sign is systemic pruritus, especially on periocular parts, external ear, interdigit spaces and lateral flank. For diagnosis of this dermatitis, complete history taking followed by intradermal skin test and serum in vitro IgE test needs to be performed. Allergen selection for the diagnosis and treatment of atopic dermatitis should be varied geographically. In this study, with intradermal skin test(IDST) the prevalence of atopic disease and what allergens are involved in are researched. Allergens used for IDST included 26 allergen extracts from six allergen groups: grasses, trees, weeds, molds, epidermal allergens and environmental allergens. The number of allergens was 42 in which the positive and negative controls are included. The most common positive allergen reaction was the house dust mites on IDST(22/35, 63%). The other positive allergen reactions were to flea(3/35, 9%), molds(1/35, 3%), house dusts(2/35, 6%), feathers (1/35, 3%), cedar/juniper(1/35, 3%), timothy grass(1/35, 3%) and dandelion(1/35, 3%). In this study, the most prevalent allergen causing atopic dermatitis in dogs in Korea was the house dust mites followed by the flea.

Relation between erythrocyte reduced glutathione and glutamate concentrations in Korean Jindo dogs with erythrocytes possessing hereditary high activity of Na-K-ATPase and a high concentration of potassium.

The concentrations of sodium, potassium, reduced glutathione (GSH) and free amino acids and Na-K-ATPase activity in erythrocytes were examined in 35 purebred Jindo dogs in Korea. The incidence of Jindo dogs with a high potassium concentration and high activity of Na-K-ATPase in erythrocytes (HK phenotype) was 25.7%. The erythrocyte GSH concentration in HK Jindo dogs varied widely, from 2.45 to 12.38 mmol/l of RBCs, and was positively correlated with the erythrocyte glutamate concentration. These results indicate that HK Jindo dogs have normal to very high levels of erythrocyte GSH, which might result from the varying quantity of Na-dependent glutamate influx in the erythrocytes.

Characterization of methicillin-resistant Staphylococcus aureus isolated from dogs in Korea.

Twelve strains of the methicillin-resistant Staphylococcus aureus (MRSA) recovered from hospitalized dogs were analyzed for in vitro antimicrobial susceptibility and virulence, and were genetically characterized by pulsed-field gel electrophoresis (PFGE). Antibiotic susceptibility test showed that nearly all isolates were resistant to beta-lactam antibiotics tested and all the strains were fully susceptible to glycopeptides. There were no inhibitory activities among the aminoglycosides. The 50% lethal dose (LD50) was determined by intraperitoneal injection of cell suspensions and estimated by the Spearman-Kärber method. The mouse lethality of MRSA and methicillin-susceptible S. aureus (MSSA) was not significantly different in both normal and cyclophosphamide-treated mice (p>0.05), indicating that they were equally virulent. There was a great difference in the incidence of toxin production between the MRSA and MSSA group; 83.3% (10 of 12) of the MRSA and 14.3% (1 of 7) of the MSSA were toxin producers. The predominant types produced by MRSA was B. All the MRSA strains were capsular type 5 producers, while of 7 MSSA strains, four were type 5, one for type 8, and two were nontypeable. Based on the PFGE analysis, the 12 MRSA isolates generated 9 to 11 fragments in the size range of <48.5 to 630.5 kb, and yielded 6 different patterns. The results indicated that production of toxin and capsule type do not play a role in the pathogenicity to mouse and PFGE is a valuable tool for the characterization of MRSA. This report is the first such cases in the veterinary literature in Korea and may indicate the frequent emergence of MRSA in veterinary clinic hereafter.

Redescription of Haemaphysalis flava and Ixodes tanuki collected from a raccoon dog in Korea

A total of 135 hard ticks consisting of 2 species of 2 genera, 117 Haemaphysalis flava and 18 Ixodes tanuki, were collected from a Korean raccoon dog (Nyctereutes procyonoides koreensis) caught at the Moaksan (Mt.). Chollabuk-do, Korea in March 1995. It is the first record that I. tanuki appears in the Korean fauna.