CASE REPORT Isolation of Haemophilus agni from Six Alberta Ram Lambs with Septicemia M. Sharon Lundberg Regional Veterinary Laboratory, Necropsy was performed within Alberta Agriculture, Post Bag No. 1, R6sum6 24 hours ofdeath on animals 1,4, 5 and Airdrie, Alberta TOM OBO t _ 6. Lambs 2 and 3 were submitted live -Six do ad_ a. and euthanized at the laboratory. ~~~~~~~~~~~~~~~~~~~~~~.... ... ... ... .. :....:.. .. }: :: .:: ..: .: ..: *Sf.re..a s. so. .abora- Necropsy Findings .Sx. ramlambs.were s itted to a,.. t de dia pour Lamb 1 had no visible lesions. Animal ..".dv . X iZ~~~~~~~~~~~~~~~~~. veernay dagnoticlaoraoryfo n6cropsie nprs one mort sobite ou une 2 had turbid synovial fluid and the illnssodahwitorwshouo jorve o.u non ventral portions of the meninges had a : : ..ag_ ...a...c.. de idepdifficu6&miriher de cloudy fibrinous appearance. Lamb 3 depressio... ..o neQ to oe.,.scour diarrh6e et de filre. Les l6uios umacro- .r fever. Gims findings an bhiit&" had congestion of the spleen and lungs. scopiques et hislog rtvrent The fourth lamb had excess serous peri- .. .. .. .. .. .. ~~~~~~.. .... ..... ... l'vidence d' sepe. On isola and : cardial fluid. ... : : :.:.. : pleural :: Hemorrhages |.. } r ~~~~was 'O# Hamokiu.::. agi & paui do cerveau, des"oumon'delaratetdeagin^._b..&~~~~~~~~~~~.....k.... were present on the serosal surface of lymphatiques. the abomasum and intestine serosa, over ... the capsule of mesenteric lymph nodes, :Ky wiords:H u ilwq epti- Mots::: H 1emoph ap, septi- and spleen, and over epicardial and cernia, sheep.o~:: -6mie- mouton. endorcardial surfaces. The lymph nodes and spleen were Introduction enlarged and the lungs and meninges Haemophilus agni is a small, This paper describes six cases of congested. Lamb 5 was in excellent pleomorphic, gram-negative coc- Haemophilus agni septicemia in young body condition with no significant cobacillus. It was first reported in 1958 rams. Clinical, necropsy, histological and gross lesions. Thecarcasswas autolyzed. by Kennedy et al (1) who isolated it bacteriological findings are described. Ram 6 was in poor body condition. from several cases of septicemia in There was superficial hemorrhage on lambs. It has since been reported from History and Clinical Findings the parietal pleura and epicardium. orchitis in rams (2). Six ram lambs (1 Rambouillet, 5 Both lungs were edematous, and stable An apparently similar organism had Suffolks), between four and six months froth was present in theterminal trachea. been reported in 1925 by Mitchell (3) ofage, were received for necropsy at the and named Haemophilus ovis. This Regional Veterinary Laboratory, Airdrie Histopathological Findings organism has more recently been over a period of ten weeks beginning Tissues for histopathology were fixed in reported from infection in lambs (4). May 16, 1985. All the lambs had ori- 10% formalin, routinely processed and Another related organism, Histo- ginated from separate flocks in Alberta stained with hematoxylin and eosin. philus ovis, was described in 1956 by and British Columbia. Five animals (1, The lungs of lambs 1, 2, 4, 5, and 6 Roberts (5) who isolated it from a case 3, 4, 5, 6) had been in close contact for had scattered microthrombi in the ofmastitis in a ewe. Histophilusovishas two months in a test station feedlot. alveolar septa with entrapped neutro- since been reported from cases ofepidi- Ram 2 died at a farm that later shipped phils and bacterial colonies. Brains of dymitis (6, 7, 8), septicemia (9) and animals to the test station. numbers 1, 2 and 6 had multifocal synovitis (10) in Australia, New Zealand Lambs 1 and 5 died with no observed neutrophilic infiltrations with occa- and England. In Canada, Histophilus signs of illness. Lambs 2 and 3 were sional vascular thrombi. The heart of ovis was the causative agent in ovine found recumbent and depressed in their lamb 4 had small multifocal areas of mastitis (11) and has been isolated from pens with no previous signs of illness. necrosis and hemorrhage infiltrated by ovine vaginal fluid (12). In addition Lamb 3 had a temperature of 42°C. neutrophils. Occasional bacterial colo- Histophilus ovis was frequently recov- Lamb 4 was found down and scouring nies were seen in the spleen and kidney ered from the genital tracts ofimmature in its pen with no previous indications unassociated with inflammatory cell rambs and ewes (13). Haemophilus of sickness. Lamb 6 was slow and stiff infiltration. somnus also resembles Haemophilus for three days prior to death. None of agni and has been reported in Canada, the lambs had received antibiotic Bacteriological Findings causing septicemia in a ram (14). therapy. Specimens for bacteriology were cul- 501 Can|Can Vet J Volume 27, No. 12 December 1986 501 infectious meningoencephalitis (19) also recognized similar disease patterns between the two organisms. At this laboratory H. agni infection was demonstrated in young feedlot = .;._.:..; lambs on concentrate rations. The .~~~~~~~~~~~~~~~~~~~~~~~~~~~~~..... ...j.;....... duration of clinical illness was acute .:''...i.ii..............:.^.:.:ij:::.j with lambs mainly found recumbent or :. :: :::.::.!:..........: dead. One with a three day illness had ..:...... ................................'...: i}.i:'::: locomotory difficulty. Haemophilus somnus also affects a juvenile bovine population on concen- trate rations resulting in acute illness, recumbency, death and occasional tured on Columbia blood agar (Difco, serum and reactions varied among the lameness. The clinical similarities are Detroit, Michigan) supplemented with isolates. followed by almost indistinguishable 5% defibrinated sheep blood, chocolate Fluorescent antibody and immuno- gross and microscopic lesions in both agar (Difco, Detroit, Michigan) sup- diffusion tests were performed at the species. plemented with 1% isovitalex (BBL, Department of Pathology, Ontario These similarities are mentioned to Becton, Dickinson and Company, Veterinary College, Guelph, Ontario, alert practitioners to an infrequently Cockeysville, Maryland) and Mac- Canada on four of the isolates. They recognized and potentially differential Conkey agar with crystal violet (Difco, were antigenically identical. Colonial diagnosis in lambs, while relating it to a Detroit, Michigan). The blood and morphology wasconsistent withHaemo- well recognized condition in the more chocolate agars were incubated in a philus agni related organisms (16). familiar bovine species. 10% CO2 incubator at 35°C while the Subsequent to the culture ofHaemo- MacConkey agar was incubated aero- Discussion philusagnireported in this paper several bically at the same temperature. The relatedness of Haemophilus agni, more isolations of the organism from Haemophilusagnigrewas aglistening Histophilus ovis and Haemophilus sheep have been made by the author. colony less than 0.5 mm in diameter in somnus was examined by Stephens in Septicemia was diagnosed in three 18 hours on both the blood and choco- 1983 (16). Haemophilus somnus exhi- animals while numerous isolations have late agars. Colonies enlarged to bits cultural, biochemical and antigenic been made from preputial washes and 1-1.5 mm by 36 hours demonstrating a properties similar to those of H. agni. swabs taken from rams at slaughter. It slight yellow pigment that was most He concluded that all the strains he would therefore seem that the pre- evident on the chocolate agar. Colonies examined were similar and should be valence ofthis organism is greater than were circular and convex with a considered as a single Haemophilus- indicated by the current literature, fur- butyrous texture and entire margin. Histophilus (HH) group. Walker in his ther emphasizing the need for more Edges were translucent with the center 1985 DNA study (17) also concluded complete taxonomic study. approaching opaqueness. No growth that these three organisms should be was observed on MacConkey agar. Ini- considered members of one species. Acknowledgments tial transfer of the organism to tryptic However, he cited evidence (18, 19) The authorgratefully acknowledges the soy agar (Difco, Detroit, Michigan) that sheep and bovine isolates are suffi- assistance ofDr. P. Frelier, Dr. S. Crowe incubated in 10% CO2 at 35°C and ciently distinct to be considered sub- and especially Dr. D. Bolingbroke in Columbia blood agar incubated aero- species. None of these organisms are the preparation of the manuscript and bically at 35°C did not yield any defined in thecurrentedition ofBergey's Dr. S. Groom forconducting fluorescent growth. However, by the third passage Manual ofDeterminative Bacteriology and immunodiffusion studies. the organism was observed growing (20). Further investigation to better sparsely on both agars. define the significance and taxonomic References Gram staining (Reeds modification) position of this organism(s) is required. 1. KENNEDY PC, FRAZIER LM, THEILEN revealed agram-negative organism with An interesting parallel can also be GH, BIBERSTEIN EL. A septicemic disease length varying from 0.5 to 1.0 microns drawn between the epidemiology and of lambs caused by Haemophilus agni (new and species). Am J Vet Res 1958; 19:645-654. occasional bacilli up to 2 microns. pathology of Haemophilus somnus in 2. ZEKI SK, KESHAVAMURTHY BS. Iso- Width was 0.3 to 0.5 microns. Several cattle and Haemophilus agni in sheep. lation of Haemophilus agni from cases of cultures exhibited a great variety of The former has been recognized since purulent orchitis in rams. Indian J Comp shapes from nearly coccoid to long, 1956 (21).