SUMMARY. Vaccination of hens, with the subsequent maternal immunity imparted to chicks, is the primary means of controlling infectious bursal disease virus (IBDV). Effective vaccination depends on rapid and accurate diagnosis of the subtype present in a flock because vaccines based on the classic subtype of IBDV can fail to protect against challenge with a variant subtype. This review describes the various methods available to detect and differentiate between IBDV subtypes. Serotype 1 IBDV causes economically significant immunosuppressive disease in young chickens. Within serotype 1, two subtypes, classic and variant, can be differentiated by the virus neutralization assay. Antigen capture enzyme-linked immunosorbent assay (AC-ELISA) with MAbs has been successful at differentiating the very virulent IBDV phenotype (vvIBDV) from less pathogenic types. More rapid and sensitive molecular diagnostic methods based on reverse transcription–polymerase chain reaction (RT-PCR) for amplification of the IBDV VP2 gene have been a major focus of investigation in recent years. Conventional RT-PCR has been useful in detecting IBDV serotypes and, to a lesser extent, differentiating IBDV subtypes. One of the approaches has been the use of SspI and NgoM IV restriction enzymes, for restriction endonuclease (RE) analysis of RT-PCR products (RT-PCR-RE) and BstNI and MboI for restriction fragment length polymorphism (RFLP) analysis (RT-PCR-RFLP) to find unique banding patterns associated with antigenic variation within the variable region of the IBDV VP2 protein. However, these approaches were ultimately found to be unreliable because subtypes could not be consistently distinguished with restriction enzymes. These limitations led to studies in differentiating subtypes by detection of single nucleotide differences in sequence through real-time RT-PCR or DNA sequencing of RT-PCR products. Conventional RT-PCR, amplifying the VP2 hypervariable region, in combination with DNA sequencing of the PCR product, can differentiate classic, variant, and vvIBDV strains because variant and vvIBDV have characteristic nucleotide and amino acid substitutions. Real-time RT-PCR, targeting different regions of the IBDV genome, including VP1, VP2, and VP4 genes, in conjunction with melting-curve analysis is being investigated as a promising tool for molecular diagnosis of IBDV infection. These methods potentially allow for more rapid, sensitive, and specific detection and differentiation of IBDV classic, very virulent, and variant subtypes.

In this study, we characterized three variant infectious bronchitis virus (IBV) strains isolated in 2003 and 2004 from broiler chickens in California and compared them to previously isolated California variant viruses and to common vaccine serotypes used in the United States. We conducted genetic, serologic, and pathogenicity studies on all three isolates, then tested different vaccines against one of the viruses. Genetically the three variant IBV strains, designated CA557/03, CA706/03, and CA1737/04, were not related to each other. GenBank BLAST database search and phylogenetic analysis of the hypervariable region of the S1 subunit of the spike gene to determine the most closely related viruses to the three variants showed the CA557/03 variant to be 81.8% similar to the CAV/CA56b/91 whereas the CA706/03 and CA1737/04 variant viruses were only distantly related to Dutch/D1466/81 (72.2%), a vaccine strain used in Europe, and Korea/K142/02 (72.7%), a Korean field isolate, respectively. Cross virus-neutralization testing showed that none of the 2003–04 California IBV variant viruses were serologically related to each other or to Ark, Conn, or Mass vaccine strains. In addition the CA1737/04 isolate was also tested against DE072 and found not to be serologically related. All three variant viruses were pathogenic in 1-wk-old broilers and vaccination with Mass/Conn followed by Holland/Conn provided 80% protection against the CA1737/04 virus. The 2003–04 California variant viruses were not compared with variants isolated in California during 1970s and 1980s because, to our knowledge, no genetic information is available and those viruses are no longer obtainable. This study shows that the CA557/03 virus was distantly related to the CAV-type viruses isolated in California in the early 1990s, but that none of the 2003–04 viruses were similar genetically or serologically to the CAL99-type viruses, indicating that new IBV variants continue to emerge and cause disease in commercial chickens in California.

Investigations were conducted to determine the occurrence of Avibacterium paragallinarum in poultry in Uganda. A total of 710 each of bacteriologic and serum samples were taken from chickens and turkeys for demonstration of A. paragallinarum and antibodies. Samples for isolation of A. paragallinarum were also subjected to direct polymerase chain reaction (PCR) for demonstration of the organism's presence. Antibodies to A. paragallinarum were demonstrated in the sera using the hemagglutination inhibition test. A total of five isolates were recovered from two out of five commercial layer chicken farms investigated where suspected cases of infectious coryza were reported, and all of them belonged to Page's serovar C. PCR detected more positive samples (11/68) than did culture (5/68). Isolates were not recovered from free-range poultry nor were there any positive samples by PCR. The overall seroprevalence was 40.5% and the seroprevalence to serovars A, B, and C were 18%, 0.5%, and 22%, respectively. Antibodies to all Page's serovars A, B, and C were demonstrated in free-range chickens but only serovar C antibodies were demonstrated in commercial chickens. No antibodies were demonstrated in turkeys. This is the first time infectious coryza has been confirmed in Uganda and the causative agent, A. paragallinarum, isolated. A high seroprevalence observed in free-range chickens seems to indicate a subclinical infection under extensive village management conditions.

A one-step reverse transcriptase–polymerase chain reaction (RT-PCR) method was developed and optimized for the detection of duck hepatitis virus type 1 (DHV-1) using the Viral Gene-spin™ viral DNA/RNA extraction kit. A pair of DHV-1–specific primers was designed against the gene encoding RNA-dependent RNA polymerase (3D gene). Using RNA prepared from duckling liver samples infected with two reference and seven Korean field isolates of DHV-1, one-step RT-PCR with DHV-1–specific primers amplified a 467-bp fragment. Under the same conditions, no amplification was observed for 14 other avian pathogenic viruses and bacteria. Using RNA prepared from serial dilutions of the DHV-1 with the supernatant of the uninfected duckling liver homogenate (10% w/v), the one-step RT-PCR assay was found to be sensitive to 10 50% egg lethal dose (ELD₅₀) 0.1 ml⁻¹ of DHV-1. Furthermore, this method detected DHV-1 from the livers and allantoic fluid of duck embryos dying before 3 days postinoculation (PI) and of chicken embryos that were chilled at 3 days PI. Therefore, this one-step RT-PCR method is rapid, sensitive, and reliable, and can be readily adapted for detection of DHV-1 from other clinical samples.

We studied apoptosis induced by duck enteritis virus (DEV) in vivo, focusing on the lymphoid organs that constitute the main targets for infection: thymus, bursa of Fabricius (BF), and spleen. Fifty Pekin ducks were inoculated subcutaneously with a virulent strain of DEV. The morphology of lymphoid organs of these infected ducks was observed by light microscopy and transmission electron microscopy. Cell death by classical necrosis was observed in lymphocytes of the DEV-infected thymus, BF, and spleen. Lymphocyte apoptosis also was observed at the same time, and it was further confirmed by in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling and agarose gel electrophoresis. We conclude that apoptosis and necrosis of lymphocytes induced by DEV infection resulted in the depletion of lymphocytes and that apoptosis of lymphocytes may play an important role in the pathogenesis of duck viral enteritis.

The live, attenuated, temperature-sensitive Mycoplasma synoviae (MS) vaccine strain MS-H is used to control virulent MS infection in commercial chicken flocks. However, the safety of this vaccine and its potential to prevent disease in turkeys have not been investigated. In this study, MS-H was shown to colonize the upper respiratory system and to induce an antibody response in turkeys but, even at the maximum release dose, was not found to cause air sac, joint, or tracheal lesions typical of wild-type MS infection. Histopathologic examinations of the vaccinated turkeys after exposure to a virulent MS challenge revealed that administration of the vaccine by aerosol, but not eye drop, at the dose recommended for chickens protected the birds against microscopic lesions and colonization of the virulent MS in trachea. It is concluded that MS-H vaccine is safe for use in turkeys and, when used as aerosol at the dose recommended for commercial chickens, can protect turkeys against tracheal lesions caused by a wild-type MS strain.

Mycoplasma gallisepticum (MG) contains two sets of rRNA genes (5S, 16S and 23S) in its genome, but only one of the two is organized in an operon cluster and contains a unique 660-nucleotide intergenic spacer region (IGSR) between the 16S and the 23S rRNA genes. We designed a polymerase chain reaction (PCR) for the specific amplification of the complete MG IGSR segment. The MG IGSR PCR was tested on 18 avian mollicute species and was confirmed as MG specific. The reaction sensitivity was demonstrated by comparing it to the well-established MG mgc2 PCR. The MG IGSR sequence was found to be highly variable (discrimination [D] index of 0.950) among a variety of MG laboratory strains, vaccine strains, and field isolates. The sequencing of the MG IGSR appears to be a valuable single-locus sequence typing (SLST) tool for MG isolate differentiation in diagnostic cases and epizootiological studies.

Salmonella enterica serovar Enteritidis is a gram-negative bacterium that negatively affects human and animal health. Many eukaryotes use antimicrobial peptides (α-defensins, β-defensins, γ-defensins, and cathelicidins) in innate immune responses to fight bacterial infections. Poultry gallinacins are the functional equivalents of mammalian β-defensins. Two related advanced intercross lines of chickens were analyzed for association of gallinacin genotypic variation with Salmonella Enteritidis burden levels in the cecum and spleen after infection. Thirteen genes of the chicken β-defensin cluster (GAL1–13) were sequenced from individuals of each advanced intercross line, plus the founder broiler sire and representatives of the highly inbred Leghorn and Fayoumi founder dam lines. The mean was 17 single-nucleotide polymorphisms (SNPs) per kilobase. One single-nucleotide polymorphism per gene was genotyped with SNaPshot to test for statistical associations with Salmonella Enteritidis colonization after challenge. Among the 13 gallinacin genes evaluated, the single-nucleotide polymorphisms in all genes in a cluster of three adjacent genes (GAL11, GAL12, and GAL13) were associated with bacterial load in the cecal content in the broiler × Leghorn advanced intercross line (three-gene SNP genotype effect, P < 0.008). The results strongly suggest a role of the gallinacins in defense of poultry against enteric pathogens. The use of gallinacin single-nucleotide polymorphisms as molecular markers for genetic selection for Salmonella Enteritidis resistance might result in reduced bacterial burden via development of an enhanced innate immune response.

SUMMARY. Avian influenza H5N1 viruses pose a significant threat to human health because of their ability to infect humans directly. In the paper, three highly pathogenic H5N1 influenza viruses were isolated from three species of migratory birds in Qinghai Province of China in 2006. The analysis of the genome sequences indicated that the three isolates shared high homology with each other (94% to 99%). Three isolates shared a common ancestor and were closest to strains isolated from Qinghai and Siberia in 2005, but distinct from poultry viruses found in Southeast Asia. In experimental infection, all three viruses were highly pathogenic to chickens and mice. The results suggest that highly pathogenic avian influenza H5N1 viruses still exist in the migratory birds and could spread to other regions with wild bird migration.

The New York 1999 strain of West Nile virus (WNV) is nearly 100% fatal in the American crow (Corvus brachyrhynchos). We evaluated four WNV vaccine formulations in American crows, including intramuscular (i.m.) DNA vaccine, i.m. DNA vaccine with adjuvant, orally administered microencapsulated DNA vaccine, and i.m. killed vaccine. Neutralizing antibodies developed in approximately 80% of crows that received the DNA vaccine i.m. (with or without adjuvant), and in 44% that received the killed vaccine. However, no crows that received the oral microencapsulated DNA vaccine or the placebo developed WNV antibodies. All crows were challenged 10 wk after initial vaccination. No unvaccinated crows survived challenge, and survival rates were 44% (i.m. DNA vaccine), 60% (i.m. DNA vaccine with adjuvant), 0% (oral microencapsulated DNA vaccine), and 11% (killed vaccine). Peak viremia titers in the birds that survived were significantly lower as compared to titers in birds that died. Parenteral administration of a WNV DNA vaccine was associated with reduced mortality but did not provide sterile immunity.

About 16,000 spent hens from 23 farms in the northern area of Japan were purchased in 1996, 1997, 1998, and 1999 to isolate Salmonella in two poultry processing plants. Salmonella was detected in 12 of 23 farms (52.2%). In particular, the serotypes Enteritidis and Infantis were detected in four and three farms, respectively. The prevalence rates in the hens' ceca, immature eggs, and the yolk of mature eggs in oviducts were 14%, 7.2%, and 6.8%, respectively. A total of 23 serotypes were detected. The major serotypes of the strains were Enteritidis, Corvallis, Typhimurium, and Infantis, but most of the strains were untypable. In the same area during 1992 to 1996, Salmonella was detected in eggs associated with four outbreaks of Salmonella Enteritidis infection and one outbreak of Salmonella Infantis infection. The ratio of contamination was approximately 1%, and the level was estimated to be 93 MPN(most probable number)/100 g in one outbreak. In farms that produced the eggs associated with all of the five outbreaks of Salmonella, the serotype Enteritidis or Infantis was isolated from hens. Farms where Salmonella was not detected were not related to any of the outbreaks.

Infectious bronchitis virus CA99 serotype was isolated from several broiler flocks in Northern California. The virus caused late-onset respiratory disease and increased airsacculitis condemnation in affected flocks despite the use of an established infectious bronchitis virus vaccination program. An experimental study compared Holland/Arkansas and Massachusetts/Arkansas vaccination protocols to determine the efficacy of commercial infectious bronchitis virus vaccines in reducing respiratory disease and airsacculitis lesions found at processing that were associated with a CA99 field isolate. All vaccination groups were given Massachusetts/Connecticut strains of infectious bronchitis virus vaccines at age 1 day followed by vaccination with either Holland/Arkansas or Massachusetts/Arkansas vaccine strains at 18 days of age. Birds were challenged at age 31 days with a CA99 field isolate. Gross pathology, histopathology, and virus isolation were evaluated. Chickens vaccinated with Holland/Arkansas had marginally better protection against CA99 challenge than chickens vaccinated with Massachusetts/Arkansas, although differences were not statistically significant.

Tibial dyschondroplasia (TD) is a major poultry leg problem, the natural etiology of which is unknown. Certain dithiocarbamate pesticides such as tetramethyl thiuram disulfide (thiram) have been shown to induce the disease in chickens. Because many different carbamate and thiocarbamate chemicals are used in a number of agricultural, industrial, and household applications, the objective of this study was to determine whether all chemicals of these categories induce TD and whether there is a concentration-dependent relationship between the ingestion of these chemicals and the incidences and the severity of the disease. Week-old broiler chicks were fed diets containing thiram or other assorted carbamate and thiocarbamate pesticides mixed in feed for 24–48 hr between ages 8 and 10 days. The birds were killed on day 15 and the proximal tibial and tarsometatarsal growth plates were evaluated for the presence and severity of TD lesions. TD was distinguished by broadening of growth plates; upon histologic exam chondrocytes appeared to be shrunken and dead. When compared by including equimolar concentrations of these chemicals in the feed, the dithiocarbamates with more than two sulfide groups, such as disulfiram, ferbam, thiram, and ziram were potent inducers of TD, whereas those with two sulfides to no sulfide group appeared ineffective at inducing TD. Both thiram and ferbam also reduced the bird's body weights. Thiram increased the incidence and the severity of the disease, denoted by TD index, in a dose-dependent manner. These results suggest that inadvertent contamination of feed or litter with some of these or similar chemicals may cause leg problems in poultry.

Avian metapneumovirus (aMPV), Newcastle disease virus (NDV), and infectious bronchitis virus (IBV) are important respiratory pathogens of chickens. To achieve early posthatch protection against all three diseases it would be helpful to deliver live aMPV, IBV, and NDV vaccines simultaneously at 1 day of age. However, previous work has indicated that the efficacy of aMPV vaccines may be affected when codelivered with IBV or NDV vaccines. The efficacy of an aMPV vaccine when codelivered to chickens in a trivalent combination with an NDV and an IBV vaccine was examined. The serological antibody response to the aMPV vaccine given with the IBV and NDV vaccine was significantly lower than when the aMPV vaccine was given alone. However, the aMPV vaccine did not affect the serological response to the IBV and NDV vaccines. Irrespective, the efficacy of the aMPV vaccine was not affected based on clinical signs postchallenge. This is the first report showing aMPV, IBV, and NDV vaccines can be codelivered without affecting the efficacy of the aMPV vaccine.

Two infectious bursal disease viruses (IBDVs 1174 and V1) were isolated from IBDV-vaccinated broiler flocks in California and Georgia. These flocks had a history of subclinical immunosuppression. These isolates are commonly used in IBDV progeny challenge studies at Auburn, AL, as well as vaccine manufacturer's vaccine efficacy studies, because they come from populated poultry-producing states, and are requested by poultry veterinarians from those states. Nested polymerase chain reaction (PCR) generated viral genome products for sequencing. A 491-bp segment from the VP2 gene, covering the hypervariable region, from each isolate was analyzed and compared with previously sequenced isolates. Sequence analysis showed that they were more closely related to the Delaware (Del) E antigenic variant than they are to the Animal Health Plant Inspection Service (APHIS) standard, both at the nucleotide level (96%, 97%) and at the amino acid level (94%, 97%). Both isolates had the glutamine to lysine shift in amino acid 249 which has been reported to be critical in binding the virus neutralizing Mab B69. Phenotypic studies showed that both isolates produced rapid atrophy of the bursae and weight loss, without the edematous bursal phase, in 2-wk-old commercial broilers having antibody against IBDV. A progeny challenge study showed both isolates produced more atrophy of the bursae (less percentage of protection) than the Del E isolate. Molecular and phenotypic data of these important IBDV isolates help in the improved detection and control of this continually changing and important viral pathogen of chickens.

An indirect fluorescent antibody test (IFA) was developed to detect West Nile virus (WNV) antigens in tissues from avian species. The test samples used in the study consisted of 100 sets of tissues from dead crows that had been collected during the 2001 surveillance in Connecticut. The test tissues were punctured with a fine point Dacron cotton-tipped applicator and smeared in duplicate on 10-well diagnostic printed glass slides. Among several fixatives tested, 4% paraformaldehyde was the best. Reagent calibration for the IFA test was done in WNV-infected Vero cells and control uninfected Vero cells. Optimized antibody and fluorescent conjugate concentrations were then applied for the detection of WNV antigen on fixed tissue impression smears. Several tissues, including brain, heart, liver, kidney, and spleen were tested by the IFA test. The brain and heart seemed to be unsuitable for the test because of excessive background. Both virus isolation and reverse transcription-polymerase chain reaction (RT-PCR) were used for validation, with the latter technique having a higher sensitivity. Therefore, IFA results were compared with RT-PCR results. The diagnostic sensitivity was 96.8% for liver, 96.4% for kidney, and 100% for spleen. The diagnostic specificity was 69% for liver, 95.3% for kidney and 95.8 for spleen. The IFA test performed best with spleen and kidney. The IFA test described here is a useful, practical, and rapid test for screening for WNV.

The maximum dosage of gamma irradiation approved by the U.S. Food and Drug Administration (FDA) for poultry is 3.0 kiloGrays (kGy). This treatment is designed to reduce bacterial contamination on uncooked poultry carcasses and meat products. The possible presence of infectious bursal disease virus (IBDV) on poultry postharvest has prompted some countries to study the risk associated with introducing nonnative strains of the virus from imported commodities. The goal of this study was to determine if this risk could be reduced using gamma irradiation to inactivate IBDV. At the dosage approved by the FDA, the titers of IBDV vaccine strains were reduced between 0 and 1 log₁₀. Titers of the pathogenic IBDV strains tested were not reduced after the 3.0 kGy exposure. Furthermore, titers of pathogenic viral strains were not reduced following exposure up to 5.0 kGy. As the exposure to gamma irradiation increased, the titers of the vaccine strains decreased. At the maximum dosage tested (10 kGy), the 89/03 variant virus vaccine was completely inactivated. Titers of the three classic IBDV vaccine strains were reduced between 1.6–2.0 logs after the 10 kGy exposure; however, these viruses remained viable after this treatment. Gamma irradiation is not an effective intervention to reduce the risk of IBDV introduction via processed poultry.

SUMMARY. An outbreak of goose parvovirus (GPV) infection on a Swedish goose farm in the spring of 2004 increased the mortality rates from 2% in the early unaffected hatches to 90% and 99% respectively in the two hatches following virus introduction and 40% in goslings hatched later in the same breeding season. In this paper we describe the clinical observations, diagnostic procedures, and epidemiologic investigation carried out to elucidate the source of the infection. The diagnosis was confirmed by serology, virus isolation, and sequence analysis of a 493-bp-long fragment of the VP1 gene. Phylogenetically the causative virus was closely related to pathogenic GPV strains isolated in 2003 and 2004 from Poland and the United Kingdom, respectively. The Swedish isolate exhibited less homology with pathogenic strains from Hungary and Asia and with attenuated vaccine strains. The epidemiologic investigation showed that the virus was first introduced to a contract farm (farm A) and then was transferred with newly hatched goslings to the farm that had submitted the birds for necropsy (index farm). The exact time and source of the virus introduction to farm A could not be determined with absolute certainty. Possible sources of the infection included backyard goose eggs that had been delivered to farm A for subcontract incubation and hatching, wild geese that frequented the flock of breeding geese on pasture on farm A, and a clutch of Canada goose eggs (Branta canadensis) that had been produced by wild geese and was hatched in the same machine as the eggs produced by farm A.

This study investigated six cases of septicemia in young crested ibises (Nipponia nippon). These birds all died with similar clinical signs, including sudden death, anorexia, diarrhea, and lameness. Immediately after death, the birds were necropsied; a blood sample was taken from heart and tissues were sampled from liver, lung, spleen, peritoneal mucus, and feces for bacteriologic examination. Anatomic observation showed that the main findings common to the sick birds were arthrocele, associated with congestion in the femur, tibiotarsus, and ventral side; swelling in the liver; hemorrhagic pericarditis; miliary tubercles in lung; and fibrous tubercles in the synovial capsule of the knee joint with suppurative abscesses. Through bacterial examination, the colonial type of Escherichia coli strain was represented prominently in cultures of the feces, heart blood, liver, lung, spleen, suppurative mucus of the synovial capsule, and peritoneal exudate. These symptoms suggested that the death of a number of endangered crested ibis within a short period was evidence of septicemia. The bacterial inoculation tests were also conducted using domestic pigeon, native chicken, and mice for the presence of and infection with E. coli. The study provided indications of the possible role of E. coli strains as bird pathogens and a potential risk in endangered species. Further work is needed to characterize E. coli strains and the toxin production in this bird. This disease occurrence also adds a note of caution to the continued efforts and interest in the reintroduction of the ibis back into its former wild ranges to ensure that formerly captive individuals do not transmit disease to the wild populations of its own or other sympatric species.

A cutaneous mycosis caused by Candida albicans that involved the combs and less frequently the wattles, facial skin, ear lobes, and neck of male broiler breeders is described. Roosters were 35 wk old and housed with hens in two conventional broiler breeder houses on a farm in western North Carolina. Morbidity was approximately 10% in one house and less than 2% in the other house. Mortality and flock fertility were not affected. Three birds from the most affected house were examined. All birds had white adherent material on their combs that presented as crusty patches or lighter diffuse areas. Often, lesions were roughly circular or had a defined margin. Small black scabs were present in a few lesions. Similar but less extensive lesions were located on the wattles, facial skin, ear lobes, and rictus. In one bird, lesions extended down the neck, and they were accompanied by hyperemia and feather loss. Hyperkeratosis with little to no inflammation and intralesional fungi occurring as yeast and pseudohyphae were seen microscopically. High numbers of C. albicans were isolated and identified from the lesions.

Four great tits (Parus major) with nodular lesions suggestive of poxvirus infections were observed in a garden in Vienna, Austria. One of the birds was submitted for examination. Because of its poor condition, the bird had to be euthanatized and was subsequently necropsied. An avipoxvirus infection was confirmed by histopathology, electron microscopy, and polymerase chain reaction and sequencing. This is the second report of naturally occurring poxvirus infection in great tits and the first of its kind in central Europe.

Increased morbidity and mortality occurred in a 5-wk-old broiler breeder replacement pullet flock. The affected broiler pullet flock was housed on the first floor of a two-story confinement building. Mortality increased to 0.1%/day compared to the flock on the second floor, which had mortality levels of less than 0.01%/day. Clinical signs in the affected chickens included inactivity, decreased response to stimuli, and anorexia. No respiratory or neurologic signs were observed. On necropsy, affected pullets were dehydrated and emaciated and had disseminated variably sized single or multiple heterophilic granulomas that contained intralesional septate and branching fungal hyphae. Lesions were extensive around the base of the heart in the thoracic inlet and in the kidneys. Other affected organs included eyelid, muscle, proventriculus, ventriculus, intestine, liver, spleen, lung, and heart. Aspergillus flavus was cultured from the visceral granulomas. The source of flock exposure to the organism was not determined.

The present study describes a subclinical necrotizing granulomatous hepatitis in normal broilers routinely slaughtered in a medium-sized (72,000 birds per day) abattoir in the Netherlands. An exploratory investigation was scheduled on line during 20-min periods for 82 flocks (3000 birds examined per period). Liver and duodenum samples were collected for histopathology from 365 birds with liver pathology. Bacteriology was performed from 240 livers with lesions and 80 control livers. In addition to the hepatic pathology, other gross lesions of the carcasses, such as footpad dermatitis and broken legs/wings, were noted. The average prevalence for gross liver lesions was 0.16% (ranging from 0% to 0.63% per flock); 89.59% of the livers were enlarged, had a firm consistency, and revealed multifocal necrotic spots. Microscopically, 51.66% showed a granulomatous reaction in addition to the necrosis. There was no consistent anaerobic or aerobic bacterial growth in comparison to normal livers. A large proportion of the livers revealed growth of Escherichia coli, Bacteroides spp., Lactobacillus spp., Staphylococcus spp., and Streptococcus spp., and this was often with more than one type of bacterial colony. The duodenum mucosa grossly showed some redness with a mucous mass on its surface. Microscopically (N  =  176) in 5.70% there were no changes in anatomy and cellular activities; 64.20% had a mildly increased number of lymphoid cells and heterophils in the lamina propria and between villus epithelial cells. The remaining 30.10% had moderate degenerative changes of villus epithelium with a mixed cellular infiltration in the lamina propria; 23.29% of the duodenum samples contained coccidia (infestation stage: mild to moderate). Signs of overgrowth with Clostridium spp. were not observed. There was a small, but significant correlation (r_s  =  0.30; P  =  0.006) between prevalence of liver pathology and footpad dermatitis.

In this study, chicken infectious anemia virus (CIAV) DNA was detected from 12-day-old broilers. Clinical history showed that the clinical features were diarrhea, blue wing disease, depression, and death. Necropsy findings were pale liver, severe atrophy of bursa of Fabricius and thymus, and discoloration of the bone marrow as well as hemorrhages subcutaneously and a few in skeletal muscles. The majority of the necropsied broilers had developed gangrenous dermatitis. Histopathology showed hypoplasia of bone marrow and depletion of lymphocytes in spleen, bursa, and subcapsular thymic cortex. Karyorrhexis of lymphocytes was scattered in the thymic cortex and most pronounced in the bursal follicles. Eosinophilic intranuclear inclusion bodies were mainly located in lymphocytes of thymus, with a few in hemopoietic cells of bone marrow. CIAV DNA was detected by polymerase chain reaction from bursa, thymus, and bone marrow. A virus strain was detected and genetically characterized in 639 base pairs of VP1 gene. Phylogenetic analysis revealed that the Greek isolate was clustered together with isolates from Alabama, China, Slovenia, and Bangladesh.

Three canaries showing feather loss on legs, dorsum, neck, and head, and hyperkeratosis on the feet were sacrificed because of their poor corporal condition and submitted to the Unit of Histology and Anatomic Pathology at the Veterinary School of Las Palmas de Gran Canaria. Histologically, skin revealed pronounced epidermal and follicular infundibular hyperplasia associated with orthokeratotic hyperkeratosis. Numerous fungal spores were observed on the stratum corneum of the epidermis and within feather follicles, associated with destruction of the feathers. This fungus was identified as Mucor ramosissimus. To the best of authors' knowledge, this is the first report of dermatitis and feather loss associated with Mucor ramosissimus, not only in canaries but also in birds.