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Campylobacter Enteritis in Dogs and Cats print email


 

A. R. Dillon, DVM, MS, Dipl. ACVIM

Department of Small Animal Surgery an Medicine

Scott-Ritchey Research Program

College of Veterinary Medicine

 

T. R. Boosinger, DVM, PhD, Dipl. ACVP

Department of Pathology

College of Veterinary Medicine

 

W. T. Blevins, BS, MS, PhD

Department of Botany and Microbiology

College of Science and Mathematics

 

Auburn University

Auburn, Alabama

 

Source:  The 36th Annual Gaines Symposium, Gastrointestinal Disor­ders of Dogs and Cats, Continuing Education Article #4, Vol. 9, No. 12, December 1987.

Sponsored by Quaker, make of

GainesR, Ken-L RationR, and Puss'N BootsR

 


 

 

KEY FACTS

*Campylobacter jejuni is a common cause of enteritis in humans and is commonly isolated from domestic and pet animals.

*C. jejuni is microaerophilic with special culture and handling re­quirements; thus "rectal swabs" for routine laboratory cultures are inadequate.

*Differences in strains of both spontaneous and experimental iso­lates probably account for the inconsistent clinical disease in­duced by this organism.

*Exposure of both pet and owner to a common source rather than pet- to-owner contamination is a likely scenario if both should develop campylobacter enteritis.

 

 

Nonculturable spiral-form gram-negative bacteria were noted in 1886 by Theodor Escherich in stool specimens and intestinal mucus from human neonates with diarrhea and from adult cats.  Later, similar organisms that would not grow on solid media were found mainly in the colon or associated with mucus in diarrhea stool specimens were described as "spirilla."  These spirilla were reported in cases of "choleralike" and "dysenteric" disease.  Growth on solid media was unsuccessful, although bacteria remained viable in liquid culture media for a few days.  Based on the mor­phologic description, the association with enteritis in neonates and infants, the failure to grow on solid media, and the fact that no other bacteria with comparable morphology had been associated with human enteric infections, this initial description of the microorganism probably describes Campylobacter species.  "In less than a decade, Campylobacter jejuni has emerged from obscurity as a veterinary pathogen to recognition as a leading cause of enteritis in human beings.  When proper culture techniques are used, C. jejuni is isolated in North America and Europe from patients with diarrhea at least as often as Salmonella or Shigella species.  Moreover,  C. jejuni has been found in virtually every country in which it has been sought.

The genus Campylobacter previously named Vibrio fetus, was recognized in 1909 as a cause of abortion in cattle and sheep.  It was not until 1977 that it was generally recognized that Cam­pylobacter  was a common cause of acute diarrhea in humans.  the genus Campylobacter (campylo meaning curved and bacter meaning rod) was proposed, separating it from Vibrio species initially on the basis of the variation of serologic and biochemical characteristics of the human isolates and ultimately on the DNA composition.

The species that in the past was classified as "related vibrios" and C. fetus subsp. jejuni is now known as Campylobacter jejuni.  The other Campylobacter species are listed in Table I ac­cording to the host(s) that each infects and their zoonotic poten­tial.  Under the present classification, C. fetus subsp. venerealis causes infertility and abortions in cattle;  C. fetus subsp.  fetus  causes abortions in sheep and is a potential human pathogen; C. sputorum subsp. sputorum is a commensal oral microbe in humans; C sputorum  subsp. bubulus and C. fecalis are commensals of the bovine reproductive and ovine intestinal tract; and C. sputorum subsp. mucosalis and C. hyointestinalis have been associated with porcine proliferative enteritis.  Campylobacter coli, which at one time was believed to be the cause of swine dysentery, and C. jejuni differ only slightly and are often discussed together as potential human pathogens.  A recently recognized species, C. laridis, is prevalent in sea gulls and has caused infection in humans; another species, C. pyloridis, is associated with peptic ulcers and chronic gastritis in humans but has unknown potential in animals.

Campylobacter jejuni is a curved, motile, gram-negative rod that requires some oxygen for growth but cannot tolerate normal oxygen concentrations in room air.  Special culture techniques are needed, therefore, for its isolation; and that may explain its relatively late discovery.  The organism is typical of gram- negative bacteria with its endotoxic properties of the lipopolysac­charide cell wall.  Campylobacter has also been implicated as releasing an enterotoxin that is cytotoxic.  In veterinary medicine, C. jejuni has generated additional interest because animals might present an important reservoir for the organism.

 

Campylobacter Enteritis in Humans

Campylobacter jejuni is a major cause of acute diarrhea in children and adults.  Recently, C. jejuni has rivaled Salmonella as a cause of enteritis and might actually be present more often than Shigella or Salmonella.  The usual incubation period of 24 to 72 hours after ingestion can extend up to 10 days.  The disease in humans is usually accompanied by fever and diarrhea (in 90

% of cases), abdominal pain (70%), myalgia, malaise, anorexia, and occasionally vomiting.  Feces are loose, usually becoming watery, mucus and blood (in 50% of cases) may be present.  The disease usually is self-limiting; recovery is complete in one to two weeks.  Deaths have been reported, however, in severe cases of C. jejuni enterocolitis.

The disease can vary and bacteremia, meningitis, and abortions have been reported.  In addition to direct tissue invasion of the bowel, the release of endotoxins or enterotoxins has been impli­cated and may be strain-specific.  The pathology is most common in the jejunum and ileum; but the colon, extending to the rectum, may be involved.

After oral ingestion, bacteria that survive the gastric acid barrier reach the bile-rich, microaerobic small intestine, where multiplication enables diarrheic patients to shed 106 to 109 bac­teria per gram of stool.  The pathology is consistent with a non­specific colitis with acute inflammation of the lamina propria, degeneration and atrophy in the goblet cells and epithelium, crypt abscesses, and mucosal ulceration.  Administration of erythromycin, the drug of choice in C. jejuni infections in humans, results in disappearance of the organism in the stool

 

Reservoirs for Campylobacter jejuni

 

Transmission appears to be by a fecal-oral route through con­taminated food and water or by direct contact with fecal material from infected animals or humans.  In general, person-to-person spread of the organism is believed to be rare.  Untreated humans can be carriers for six weeks during convalescence, and shedding can occur for up to one year in some cases.

For the veterinarian, the zoonotic potential of pet-owner con­tact is important.  In domestic animals, the organism is almost ubiquitous.  In mammals, C. jejuni has been isolated from healthy cattle, sheep, horse, pigs, goats, dogs, cats, rodents, and monkeys and from diarrheic calves, lambs, dogs, cats, and monkeys.  In avian species, C. jejuni has been isolated from 30% to 100% of fe­cal samples.  Once fecal contamination has occurred, viable or­ganisms can be present for up to four weeks.  The organism also has been isolated from fresh and salt water and has survived up to five weeks in fresh, untreated water.

Because campylobacter enteritis in humans is clearly a zoonosis with animals as an important reservoir, both dogs and cats are sources of infection.  How important they are as sources is still uncertain.  Skirrow and Benjamin stated that in Britain no more than 5% of cases of campylobacter enteritis in humans have been associated with dogs and cats, and those zoonoses were as­sociated with newly acquired puppies.  Recently, C. jejuni infec­tion in a young woman was associated with infection in an ap­parently healthy adult cat.

Despite the ubiquitous nature of the organism, the epidemiologic associations of C. jejuni are not well established.  Outbreaks with water and milk as the vehicles of transmission have been confirmed.  The evidence for ill-cooked chicken as a source is interesting but not conclusive.

Based on matched controlled studies of sporadic human C. jejuni enteritis in Colorado, the odds ratios of increased risk factors were noted for drinking raw water (10.7), drinking raw milk)6.9), eating undercooked chicken(2.8), and living in a household with a cat(3.2).

In a study of human cases of diarrhea in Japan, 188 of 881 cases had C. jejuni isolated from the stool and the rates of posi­tive stool cultures of animals in the area were cattle (12%), chickens (45%), dogs (5%), and cats (10%).  The strains found in chickens most closely resembled the human isolates.

Studies on heat-stable antigens using unabsorbed anti-sera of human isolates compared with domestic farm isolates indicated a high similarity index for, in decreasing order, poultry, wild birds, flies, and pigs.  The predominant porcine strain was never isolated from humans, and the strains found in flies closely resembled those from animals in the area.  Serotyping also showed a close relationship between isolates of human and chicken origin but little relationship between human and pig strains.

Although the sources of human infection are usually poultry, unpasteurized milk, contaminated water, and direct contact with animals with enteritis, food poisoning caused by campylobacter ap­pears to be uncommon, unlike the situation with Salmonella.  Cam­pylobacter dies during cooling of pork and beef carcasses because of drying effects of ventilation.  Furthermore, the inability of the organism to grow at temperatures below 30oC (86oF) and its microaerophilic nature would make contamination of most foods, ex­cept for chicken and vacuum-packed processed meats, uncommon for Campylobacter.

 

Typing of Campylobacter jejuni

With the increasing interest in the zoonotic potential oC. jejuni, several methods of distinguishing strains have been developed.  Criteria for classification of C. jejuni are summarized in the box on this page.  Serotyping, biotyping, and phage-typing techniques have helped differentiate pathogenicity of different strains but have not clearly discerned the role fo the small pet animal in the epidemiology.  Most of the methods are technically difficult and expensive, and reliance on only one can be confusing.

In a human outbreak of C. jejuni associated with dogs, a lit­ter of 11 puppies was given to local residents of a community.  All but 1 of the puppies died with enteritis, and people in most of the household with puppies developed diarrhea.  Campylobacter jejuni was diagnosed in nine households involving 16 human cases.  Use of 2 serologic methods and 1 biotyping scheme, however, revealed that 3 different strains were involved in the outbreak.

Even with the use of hemagglutination methods of serotyping, a slide agglutination method, and the biotyping scheme of Preston, confusion exists as to the best method for strain classification.  Serology involves the separation of strains by the tolerance to heat of the somatic, flagellar, and capsular antigens (O, H, and K).  Evaluation of data suggests that heterogenicity within ap­parently similar strains exists.  Strains that are of similar serotypes may be of different biotypes, or strains by the same biotype may be of the same serotype according to one but not another serologic method.  Further confusion is inherent in the ability of the strains of Campylobacter to change antigenicity with serial passage in vivo and in vitro.  Thus, it has been suggested that a serotyping scheme should always be combined with a biotyping scheme to document an epidemiologic study of an outbreak when human, animal, and environmental isolates are involved.

Plasmids in Campylobacter Isolates

The rate of occurrence of plasmids in Campylobacter isolates in diarrheic humans (9.5%), pigs (83.3%), and poultry 0 % to 100% depending on flock; mean 58%) indicates variability and probably adaptability of the organism.

Animal isolates of Campylobacter species frequently have plas­mids of various molecular weights.  For plasmids that act as R fac­tors, the high frequency of plasmid DNA may result from the ex­posure of the organisms to antibiotics present in animal feeds.  Under normal conditions, plasmids can be superfluous and tend to be lost; when plasmid function becomes essential for survival, cells containing the appropriate plasmid will be selected.  These genetic loci may be transient and unstable and lost or gained based on necessity.  In addition to antibiotic resistance, plasmids may en­code for phenotypic traits involved in virulence, toxicity, and hydrocarbon catabolism.  The pathogenic potential of C. jejuni to invade and produce enterotoxin has been confirmed.  The possibility exists, as in Escherichia coli, that there might be a separate plasmid-induced property of either invasiveness or en­terotoxigenicity.  Several researchers have identified a choleralike enterotoxin produced by strains of C. jejuni.

Screening of C. coli and C. jejuni strains from domestic animals revealed plasmid profiles that varied according to the health status of the animal host.  The frequency of plasmids in diarrheic cattle with C. jejuni was higher than in normal cattle.  Isolates showing resistance to ampicillin, tetracycline, and gen­tamicin were more likely to contain plasmids, suggesting a probable plasmid-mediated resistant for tetracycline and perhaps gentamicin.  A tetracycline-resistant plasmid has not been associated with en­terotoxin or cytotoxic activity.

Plasmid profiles have indicated homology between DNA-encoding tetracycline resistance in Campylobacter species and tetracycline resistance from Streptococcus species indicating a transfer of genetic information between gram-negative and a gram-positive coc­cus.  Tetracycline resistance could not be transferred to E. coli by conjugation or transformation, suggesting that transfer between Campylobacter and unrelated gram-negative organisms is unlikely.

 

Campylobacter in Dogs and Cats

The interest in C. jejuni in dogs and cats has been directed at documentation of the prevalence of the organism in diarrheic and healthy dogs and cats.  Attempts have also been made experimentally to induce infestation or infection.

 

Clinical Evidence

Although it is clear that C. jejuni can cause enteric disease in humans with relatively few organisms (500 bacteria per os), the pathogenicity is unclear in dogs and cats.  Campylobacter species have been isolated from both normal and diarrheic dogs at about the same frequency, suggesting that Campylobacter species are not primary pathogens of dogs.  Reported canine isolates indicate that C. jejuni may be a cause of diarrhea in dogs and can be found more frequently in diarrheic dogs.

Conditions associated with increased frequency of isolation of C. jejuni in dogs and cats are summarized in the box below.  Dif­ferences in the animals' ages, degree of sanitation, and environ­ment of the survey populations might explain the discrepancies in the reported rate of infection.  The histories of the dogs surveyed often are not documented.  The young puppy in a concentrated population with poor sanitation, such as an ill-kept kennel, has the greatest potential for exposure.  Isolation frequency ranges from less than 5% to as high as 90% in puppies.

 

 

Conditions Associated with Increased Frequency of Isolation of Campylobacter jejuni in Dogs and Cats

Diarrheic animals

Young animals

Concentrated housing or poor sanitation

Stressful conditions

New arrivals in kennel

Pregnancy, surgery

Other enteric pathogens

Parvovirus, Salmonella, Giardia, parasites

 

In reported spontaneous Campylobacter-associated diarrhea, dogs developed a mucous, watery, and occasionally bloody stool of 5 to 15 days duration.  Anorexia, vomiting, and a febrile response have been noted.  In that these are nonspecific signs and the dis­ease reportedly is most common in the young, the differential diag­nosis would include all causes of acute enteritis in dogs.  The higher incidence of disease in the young, in poor kennel condi­tions, in stressed adult dogs, and concomitant with other intes­tinal disease agents would indicate that the organism may be syner­gistic or opportunistic in the mechanism of disease.  The synergis­tic role of C. jejuni in parvovirus infections has been documented, and there has been speculation on a potential role for other viral agents.  Campylobacter jejuni-associated disease in adult dogs can clinically and histopathologically mimic parvovirus infection and should be considered in dogs developing diarrhea after environmen­tal, physiologic, or surgical stress.

In one study, Campylobacter jejuni was isolated from 29% of dogs and 21% of cats with diarrhea as compared with 4% of normal dogs and cats.  Campylobacter coli was isolated from dogs (8%) and cats (5%) with diarrhea but rarely from normal dogs (2%) or cats (0%).  The rate of occurrence of C. jejuni in positive stools from laboratory beagles was higher in diarrheic (90%) than in normal (63%) dogs.  The occurrence in privately owned healthy dogs would generally appear to be low (3.8%) compared with dogs in public ken­nels (12.8%).

In young (less than six months old) dogs, the influence of stress is supported by finding C. jejuni in 3.1% of healthy dogs, 21.7% of dogs with diarrhea, and 6.7% of dogs without diarrhea but sick from other causes.  In a production colony of beagles with a 14.7% infection rate (25% in the young and 3.9% in adults, ) the rate of infection in recently acquired dogs was 32%.  Evaluation of age and stress demonstrated that on arrival at the kennels there was no difference in the rate of isolation among dogs less than or over six months of age; however, a significant increase in the rate of isolation by Days 5 to 7 compared with Day 1 was noted, suggest­ing that while dogs may acquire campylobacter infection in kennels, excretion of the organism may be intermittent and precipitated by stress.

The incidence in cats is less well described than in dogs.  Campylobacter jejuni has been isolated from feces of up to 45% of nondiarrheic cats.  The infection rate seems to be low, however, in most cat populations in which good hygiene is practiced.  No cor­relation between the environment or age of animal and incidence of infection was noted in a population of cats, 1% of which had cam­pylobacter isolates.  Contact of uninfected cats with cats shedding the organism caused a transient diarrhea in the previously healthy cats, and the sporadic pattern of excretion of organisms tends to make diagnosis based on one culture difficult.  Clinical signs in another cat with seroconversion abated when treated, and the or­ganism could not be recultured from the stool.  In another report, C. jejuni was isolated from 21% of diarrheic cats compared with 4% of normal cats, similar to the rates in dogs (29% of diarrheic dogs versus 4% of normal dogs).

 

Experimental Evidence

The incidence of positive stool cultures for C. jejuni provides serious confusion and consternation for the veterinarian.  Given the fact that the organism can be found in normal, adult dogs but is isolated more frequently in young, diarrheic, stressed dogs, the diagnosis can be elusive as far as a cause and effect relation­ship.

Variables associated with experimental infection of dogs with C. jejuni include the following:

 

*Selection of pathogenic strain

*Serial passage of strains versus frozen (-70oC)

*Number of organisms for inoculation

*Route of delivery of infective dose

*Animals host conditioning

*Concomitant disease

 

Although initially unsuccessful in producing diarrhea in puppies with Campylobacter species of human origin, a mild diarrhea was produced in gnotobiotic beagle puppies using either human or canine isolates of C. jejuni.  A moderate, superficial, erosive colitis was noted.  Feces from infected puppies became increasingly fluid at the peak of the illness.  Other signs were tenesmus, las­situde, and mild anorexia.  In contrast with the disease in humans, the clinical disease in dogs appears to be less severe and to re­quire more infective organisms.  Reports of induction of enteritis in conventional puppies and fieldwork with natural cases indicate that a 7- to 10-day course of semiformed to watery stools with mucus and occasional blood, tenesmus, and ileus, as in humans, oc­curs in conventional dogs rather than just a colitis as in the gnotobiotic dogs.

Inconsistencies in the experimental induction of the disease obviously center on the source and method of inoculation of the or­ganism.  given the multiple strains and the ability of the organism to change both in vivo and in vitro, laboratory manipulation before inoculation may influence  the pathogenicity of the C. jejuni to be tested.  The difficulty in inducing the disease in gnotobiotic beagles must also be viewed in reference to the synergistic role of other enteric pathogens.  Oral inoculation of up to 8.8 x 109 or­ganisms from diarrheic dogs to puppies did not induce disease, but the organism multiplied in 60% of the cases and was excreted for two to seven weeks.

Organisms that are pathogenic in humans can reproduce, shed and cause seroconversion in dogs.  Although this is of public health concern, the role of the bacteria as a primary pathogen is still in doubt.  The higher incidence in the young, in animals un­der stress, and in animals with diarrhea is too compelling to allow veterinarians to ignore the role of C. jejuni as at least a secon­dary pathogen.  Careful challenge with an endotoxin-producing strain with known human pathogenesis would illuminate the role of C. jejuni as a primary pathogen in dogs and cats.

The histologic pattern may depend on the strain of the or­ganism but the ileum, cecum, and colon are primarily involved.  Mucosal hyperplasia, blunting of intestinal villi, inflammatory cell infiltrates of the lamina propria, and Peyer's patches have been described in dogs.  Campylobacter jejuni can be found, however, in the stools of dogs with diarrhea even when none of the above histologic changes are observed.  In one study of 32 strains isolated, 43% were from the rectum, 75% from the colon, and 81% were from the cecum.

In Sweden, thermotolerant, catalase-negative, hippurate- positive Campylobacter species have been isolated from diarrheic humans and dogs that have been considered non-enteropathogenic.  Based on DNA studies, this "Swedish catalase-negative or weak strain" closely resembles C. jejuni.  Clinical signs ascribed to a similar Campylobacter species in a dog that responded to an­tibiotics have been described.

 

Identification of Campylobacter jejuni

Examination of diarrheic feces by dark-field or phase-contrast microscopy can permit a presumptive diagnosis and suggest whether fecal cultures are indicated.  The finding by the untrained ob­server of motile curved rods darting across a microscopic field is nonspecific and not definitive.  The use of Gram stain on human stool specimens for early presumptive diagnosis has been reported.

Campylobacter jejuni are gram-negative, slender, curved (vibrio), S-shaped, or "sea gull-shaped" bacteria with tapered ends.  They are 0.2 to 0.4 um in width and vary from 1.5 to 3.5 um in length, depending on the shape of the particular bacterium.  The organism is microaerophilic with an optimal growth temperature from 37o to 42oC (98.6o to 107.6oF).  Campylobacter jejuni will not grow at 25oC (77oF) nor does it tolerate atmospheric concentrations of oxygen, thus it is very important that fecal specimens or swabs be processed soon after collection.  The specimens should be kept chilled (4oC [39.2oF]); if the sample is a swab it should be placed in an anaerobic transport medium.

Isolation of C. jejuni from stool specimens can be difficult and requires from two to five days.  Special requirements include selective techniques to reduce the growth of competing organisms and microaerophilic (not anaerobic) incubation conditions (5% oxygen, 10% carbon dioxide, and 85% nitrogen).  The use of selec­tive campylobacter-specific medium (commonly known as "Campy-BAP") gives better recovery of the isolation and identification of cam­pylobacters have been published.

Antibody titer techniques being developed will augment the current knowledge and provide a clearer prospective of the clinical importance of campylobacters in dogs and cats.  The isolation of Campylobacter jejuni does not confirm the organism as the causative agent in dogs and cats with diarrhea.  Specific serum antibodies in humans can be detected after C. jejuni infections using tube ag­glutination, bactericidal assays, and indirect immunofluorescence.

 

Therapy

Antibiotic therapy for C. jejuni enteritis in dogs or cats has not been experimentally evaluated.  Therapy of spontaneous cases has resulted in elimination of the organism in the stools.  In that the disease is usually self-limiting and rarely disseminated, therapy may not affect the clinical course of the disease but might decrease the duration of bacterial shedding.

Based on a series of experiments of antibiotic sensitivity patterns of C. jejuni, high concentrations of ampicillin, penicil­lin, tetracycline, and metronidazole were required to inhibit growth.  Because Campylobacter is believed to produce B-lactamase, most strains are relatively resistant to ampicillin and other re­lated antibiotics.  More isolates containing plasmids were resis­tant to tetracycline, gentamicin, and ampicillin than were isolates not carrying plasmids.  This tendency has been shown especially for tetracycline and gentamicin.  In general, most isolates were sus­ceptible to gentamicin, kanamycin, neomycin, erythromycin, and sul­fonamide.  Erythromycin is the drug of choice for therapy in humans, although resistant strains have been noted in human and animal isolates.  In a retrospective trial in children with cam­pylobacter enteritis, erythromycin did not alter the course of the disease but did decrease the duration of bacterial shedding.  The use of erythromycin in dogs with campylobacter enteritis did not change the clinical signs when compared with fluid therapy alone.  Furazolidone was affective at low minimum inhibiting concentrations (MIC), and resistance to the antibiotic apparently is rare.  Chloramphenicol and doxycycline were effective, but canine isolates resistant to both antibiotics have been reported.  The use of chloramphenicol for one week in a dog with campylobacter enteritis (the organism was catalase-negative and sodium hippurate-negative but was not C. jejuni) did result in abatement of clinical signs and in the elimination of the organism from the stool.  Resistance to sulfamethoxazole and trimethoprim was high (60.2%) in isolates of C. jejuni and C. coli.

With the increased incidence of transmission of antibiotic- resistant Salmonella to humans and the apparent increase in plasmid- mediated resistance in other enteric bacteria in response to the widespread use of antibiotics, the zoonotic potential of campylobacters in obvious.  It would appear, however, that trans­mission of plasmid-mediated resistance among strains of E. coli and C. jejuni does not occur.  Comparison of the antibiotic sensitivity of C. jejuni/C. coli strains isolated from dogs and cats with acute enteritis from 1981 to 1986 with the exception of chloramphenicol, which did show, however, an increase in isolates that were only moderately sensitive.  Increases in percentages of antibiotic-resistant isolates from 1981 to 1986 included 56.4% to 85.7% for benzylpenicillin, 17.9% to 41.3% for ampicillin, 0% to 9.5% for tetracycline, 0% to 8% for erythromycin, 10.3% to 65.1% for strep­tomycin, 2.6% to 4.8% for gentamicin, 0% to 4.8% for kanamycin, 0% to 9.5% for neomycin, and 7.7% to 14.3% for polymyxin B.  All of these antibiotics had been used in the area of Germany in the years examined and the increases in resistance may reflect the bacterial response to the antibiotic pressure.

From the data, erythromycin or chloramphenicol would appear to be the therapeutic drug of choice; however, C. jejuni suscep­tibility can be variable.  In vitro antibiotic testing should be performed before therapy is instituted.  The isolation of the causative organism and determination of antibiotic sensitivity are of increased importance because of the zoonotic potential of C. jejuni.

 

The Role of the Small Animal Practitioner

A C. jejuni infection in dogs or cats cannot be clinically distinguished at this time.  Furthermore, isolation of the organism from healthy or diseased dogs or cats is not sufficient to warrant a diagnosis of enteritis.  With the increased awareness of the or­ganism, however, pets should be considered a potential reservoir for human infection and child-puppy contact may be questioned in the future.  Although less than 5% of human C. jejuni enteritis cases are reportedly acquired from dogs, the history of development of diarrhea in the owner(s) after a previous bout of diarrhea in a puppy is suggestive.  This implication would be strengthened if the pet were newly acquired or had been recently stressed or if poor sanitation were suspected.

Small numbers (500) of C. jejuni potentially can cause infec­tion in humans; therefore, the possibility of acquiring an infec­tion from contact with feces from an infected or carrier pet animal is real.  This hazard would appear to be more likely than with Sal­monella species in which large numbers (105 to 107) usually are re­quired for human infection.  The zoonotic potential of campylobac­ter enteritis is compared with that of Salmonella enteritis in Table II.  The large reservoir and multiple modes and vehicles of transmission would dictate that clients developing C. jejuni en­teritis should examine water, meats, and foodstuffs, and milk for contamination before the pet dog or cat is incriminated as the source.  If both pet and owner are affected, the most likely scenario would be the exposure of both pet and owner to a common source.

For both pet and owners and veterinarians, the basics of good hygiene and the necessity for hand-washing after contact with diar­rheic animals or feces are reinforced by this disease.  For the practitioner, the isolation of hospitalized puppies with enteric disease and the careful handling of their feces is recommended for the benefit of both the animal handlers and other hospitalized pets.  When it is determined that a diarrheic pet is shedding C. jejuni, antibiotic sensitivity testing and the initiation of erythromycin therapy are indicated.  Good client education and professional awareness should avoid potential problems until more answers are available.

 

TABLE II

Comparisons of Zoonotic

Potential of Bacterial Enteritis

 

                                                                             Salmonella                        Campylobacter

 


 

Growth                                                                   Easy                                       Special

Typing                                                                   Established                           Developing

Identification                                                            Easy                                       Easy

Growth in meat                                                         +++                                         ?

Growth in milk                                                          +++                                         No

Normal flora                                                           +                                              +++

Infective dose                                                           ++++                                       +

Dissemination                                                           ++                                           ?

Person-to-person contact                                          +++                                         +?

Carriage                                                                 3 months                                +?

 

 

 

 

 

 

Original Doc: campy.doc