CROSS-CANADA DISEASE
`REPORT
`
`RAPPORT DES MALADIES
`,
`DIAGNOSTIQUEES AU CANADA
`
`Quebec
`Salmonella infection in wild birds
`tions, gross lesions are highly variable and may con(cid:173)
`sist of necrotizing to pyogranulomatous hepatitis,
`from Quebec
`An adult house sparrow (Passer domesticus) with
`and fibrinopurulent enteritis and arthritis. The diag(cid:173)
`nosis is confirmed by laboratory isolation and iden(cid:173)
`tification of salmonellae. Isolation of Salmonella
`spp. only from the intestine of birds with no lesions
`generally indicates that the bird was an asymptomatic
`carrier (3).
`It is generally believed that wild birds do not playa
`major role in the epidemiology of human salmonel(cid:173)
`losis (2-4). However, when a large number of birds
`roost at the same site, they may represent a potential
`health hazard to humans and other animals (4). Birds sus(cid:173)
`pected of having salmonellosis and any material con(cid:173)
`taminated by their feces should be handled carefully to
`prevent human exposure.
`
`severe bilateral conjunctival swelling was admitted
`to a rehabilitation center. The bird received topical
`antibiotic therapy but died within 36 h. Necropsy
`revealed severe bilateral distension of the infraorbital
`sinuses, with exudate consisting of fibrin, a moderate
`number of necrotic macrophages, a few heterophils,
`and colonies of gram-negative bacilli. Salmonella
`typhimurium were isolated in pure culture from the
`infraorbital sinuses; they were identified using the API
`20E system (Bio-Merieux Vitek, Hazelwood, Missouri,
`USA). Results from cultures for Mycoplasma spp. were
`negative.
`From 1992 to 1997,6 cases of Salmonella typhimurium
`infection have been diagnosed by the Quebec branch of
`the Canadian Cooperative Wildlife Health Centre from
`a total of 632 submissions of wild birds. Salmonellosis
`was diagnosed 3 times in individual birds (this sparrow,
`a great homed owl (Bubo virginianus), and a black(cid:173)
`legged kitiwake (Rissa tridactyla), and in 3 die-offs,
`1 involving 38 ring-billed gulls (Larus delawarensis) and
`2 involving 30 and 8 house sparrows, respectively. The
`case anamneses were sudden death (3/6), lethargy (3/6),
`eye swelling (2/6), or diarrhea (1/6). Necropsy find(cid:173)
`ings were poor body condition (6/6), multifocal necro(cid:173)
`tizing to pyogranulomatous hepatitis (3/6), fibrinopu(cid:173)
`rulent typhlitis (1/6), ingluvitis (1/6), and infra-orbital
`air-sacculitis (1/6). Concomitant air-sacculitis with intra(cid:173)
`lesional Aspergillus spp. was diagnosed in 2/6 cases.
`Wild birds are often asymptomatic carriers of
`Salmonella spp. The prevalence of infection ranges
`from 1.9% in falconiform birds (1) to 8.7% in ring(cid:173)
`billed gulls (2). However, clinical avian salmonel(cid:173)
`losis is seldom reported, except for outbreaks in
`passerine birds at backyard bird feeding stations
`and in aquatic birds.
`In acute salmonellosis, death can occur without
`causing gross lesions. In subacute and chronic infec-
`
`References
`I. Kirkpatrick CE, Trexler-Myren YP. A survey of free-living fal(cid:173)
`coniforrn birds for Salmonella. J Am Yet Med Assoc 1986; 189:
`997-998.
`2. Quessy S, Messier S. Prevalence of Salmonella spp., Campylobacter
`spp. and Listeria spp. in ring-billed gulls (Larus delawarensis).
`J Wildl Dis 1992; 28: 526-531.
`3. Stroud RK, Friend M. Avian salmonellosis. In: Friend M, Laitman
`CJ, eds. Field Guide to Wildlife Diseases. vol I. General Field
`Procedures and Diseases of Migratory Birds. Washington, DC:
`US Department of the Interior, Fish and Wildlife Service, 1987:
`101-106.
`4. Wilson JE, MacDonald JW. Salmonella infection in wild birds.
`Br Yet J 1967; 123: 212-219.
`
`Igor Mikaelian, Canadian Cooperative Wildlife Health
`Centre and Centre Quebecois sur la Sante des Animaux
`Sauvages; Danielle Daignault, Departement de patholo(cid:173)
`gie et de microbiologie; Marie-Claude Duval, Clinique
`des Oiseaux de Proie; Daniel Martineau, Canadian
`Cooperative Wildlife Health Centre and Centre Quebecois
`sur la Sante des Animaux Sauvages; Faculte de medecine
`vererinaire, Universite de Montreal, Saint-Hyacinthe
`(Quebec) J2S 7C6.
`
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`Manitoba
`Detection and characterization
`(l,2). The disease has been diagnosed in Alberta,
`of porcine circovirus associated
`Saskatchewan, and Manitoba. An etiologic association
`of porcine circovirus (PCV) with PMWS has been ques(cid:173)
`with postweaning multisystemic
`tioned by some workers, due to the ubiquitous presence
`wasting syndrome in pigs
`of this virus in the pig population. The virus has also been
`Postweaning multisystemic wasting syndrome
`recognized as a natural inhabitant of PK -15 cell lines.
`Publications on this virus primarily address the char(cid:173)
`acteristics of PCV isolated from PK -15 cell lines. In 1 of
`
`(PMWS) is a recently recognized disease of pigs. The
`typical clinical signs and pathology have been published
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`Can Vet J Volume 38, June 1997
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`385
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`CEV Exhibit 1014_001
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`the original studies, Tischer et al (3) reported that PCV
`was not pathogenic for experimentally infected pigs. In
`a recent study (4), the PCV antigen was demonstrated in
`the spleen from stillborn piglets, but the authors con(cid:173)
`cluded that the virus was not a significant cause of
`reproductive disorders in Northern Ireland. The virus also
`appears to be common in the Canadian swine population,
`as indicated by the previously reported prevalence of
`PCV antibodies (5) .
`Recently, we tested approximately 100 pigs with
`clinical signs and pathology consistent with PMWS
`for porcine circovirus using a polymerase chain reaction
`(PCR) test. The test was developed at the Virology
`Laboratory of the Veterinary Services Branch of
`Manitoba Agriculture (6) and modified for the detection
`of PCV DNA. The tissues assayed were lung, tonsil,
`spleen, or intestines. Porcine circovirus DNA was
`detected in 15 cases. Three of the 15 cases that were pos(cid:173)
`itive for PVC DNA were also positive for porcine res(cid:173)
`piratory and reproductive syndrome virus (PCR test).
`Two of 15 were positive for Mycoplasma hyopneumoniae
`(PCR test), and all were negative for swine influenza
`virus (PCR test).
`The DNA products of PCR amplification from the
`15 cases that were positive for PCV DNA were then sub(cid:173)
`jected to restriction enzyme (RE) cleavage map analy(cid:173)
`sis. At least 3 RE types of PCV were identified from pigs
`with PMWS. Five of the 15 cases had more than 1 RE
`type of PCV. We are continuing our efforts to charac(cid:173)
`terize more RE types by RE mapping and to determine
`the complete nucleotide sequence of the PCV genome
`obtained from clinical PMWS cases.
`Using RE mapping results, the nucleotide sequence
`of PCV from pigs with PMWS was also compared
`
`with that of PCV from PK-15 cell lines and from a
`PCV isolate reported by Irish workers (7). We con(cid:173)
`cluded that the RE types of PCV from pigs with
`PMWS were different from the RE types of PCV
`isolated from other sources and which were not con(cid:173)
`sidered pathogenic. We further concluded that spe(cid:173)
`cific strains or variants of PCV can be pathogenic and
`may be associated with PMWS.
`
`References
`I. Harding JC. Post-weaning multisystemic wasting syndrome
`(PMWS): Preliminary epidemiology and clinical presentation.
`Proc Am Assoc Swine Pract 1997: 503.
`2. Clark EG. Post-weaning multi systemic wasting syndrome. Proc Am
`Assoc Swine Pract 1997: 499-501.
`3. Tischer I, Mields W, Wolff D, Vagt M, Griem W. Studies on the
`pathogenicity of porcine circovirus. Arch Virol 1986; 91: 271-276.
`4. Allan GM, McNeilly F, Cassidy JP, et al. Pathogenesis of porcine
`circovirus: Experimental infections of colostrum deprived piglets
`and examination of pig foetal material. Vet Microbiol 1995; 44:
`49-64.
`5. Dulac GC, Afshar A. Porcine circovirus antigens in PK-15 cell line
`(ATCC CCL-33) and evidence of antibodies to circovirus in
`Canadian pigs. Can J Vet Res 1989; 53: 431-433.
`6. Hamel AL, Wasylyshen MD, Nayar GPS. Rapid detection of
`bovine viral diarrhea virus by using RNA extracted directly from
`assorted specimens and a one-tube reverse transcription PCR
`assay. J Clin Microbiol1995; 33: 287-291.
`7. Meehan 8M, Creelan JL, McNulty MS, Todd D. Sequence of
`porcine circovirus DNA: Affinities with plant circoviruses. J Gen
`Viro11997 ; 78: 221-227.
`
`Gopi P.S. Nayar, Andre Hamel, Lihua Lin, Virology
`Laboratory, Veterinary Services Branch, Manitoba
`Agriculture, 545 University Crescent, Winnipeg, Manitoba
`R3T 5S6.
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`British Columbia
`Protozoal dermatitis of farmed
`Atlantic salmon in British Columbia
`In April 1995, protozoal dermatitis due to a Kudoa
`
`sp, was diagnosed in farmed Atlantic salmon in British
`Columbia. The affected site, located in the coastal
`waters of British Columbia, contained 450 000 Atlantic
`salmon (Salmo salar), weighing an average of 1.5 kg.
`The salmon were distributed evenly amongst 40 seacages,
`which measured 15 m at the surface and extended to a
`depth of 17 m. Depth from the bottom of the seacages to
`the ocean floor averaged 380 m. The ambient water
`temperature, recorded 3 m below the surface, was 9.8°C.
`The fish were fed an adequate diet, which was com(cid:173)
`mercially prepared.
`Fish in 6 cages located at 1 end of the netpen system
`were observed to have areas of skin discoloration.
`Affected salmon (Figure 1) had randomly distributed,
`metallic blue, foci or larger irregular patches on the
`skin of the dorsal surface of the fish and the pectoral,
`pelvic, dorsal, adipose, and tail fins. Affected salmon
`were not sexually mature or "grilse." The fish had no
`prior history of disease and had not been treated within
`the past year with a systemic therapeutic agent.
`
`Figure 1. Dorsal view of Atlantic salmon (Safmo safar)
`showing metallic blue foci and patches on skin of fish infected
`with a Kudoa sp.
`
`Based on clinical observation of fish at rest and while
`feeding and observations from the "mort" divers, the
`morbidity rate for each cage of affected salmon with skin
`lesions varied from 5% to 10%. The total mortality
`rate for the site was 0.01 % per month, which was within
`the acceptable range of production loss for this size of
`fish for this fish farm company. Salmon with skin
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`Can Vet J Volume 38, June 1997
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`CEV Exhibit 1014_002
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