LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II GUINEA PIGS: Infectious Diseases V-9025 Donna J. Clemons, DVM, MS Lizabeth A. Terril, DVM Joseph E. Wagner, DVM, MPH, PhD Department of Veterinary Pathology College of Veterinary Medicine University of Missouri Columbia, Missouri The Laboratory Animal Medicine and Science - Series ll - has been developed by the Autotutorial Committee of the American College of Laboratory Animal Medicine (ACLAM): C. W. McPherson, DVM, Chair; J. E. Harkness, DVM;J. F. Harwell, Jr., DVM; J. M. Linn, DVM; A. F. Moreland, DVM; G. L. Van Hoosier, Jr., DVM; L. Dahm, MS. Instructional development and production assistance provided by L. Dahm, MS, and B. J. McGough, BS Medical Comm. The development of these programs is supported by a grant from the US Department of Agriculture: National Agricultural Library grant 59-32U4-9-45 Laboratory Animal Medicine and Science - Series II is produced by the Health Sciences Center for Educational Resources University of Washington. 2 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II PRIMARY AUDIENCE Veterinary students and graduate veterinarians studying laboratory animal diseases. SECONDARY AUDIENCE Investigators using laboratory guinea pigs, research technicians, veterinary technicians, and laboratory animal technicians. GOAL To provide the viewer with an understanding of the causes, frequency of occurrence, clinical and pathologic signs, diagnosis, treatment and prevention, control, and significance of infectious diseases of guinea pigs. OBJECTIVES Given a guinea pig or a description of a guinea pig assumed to be diseased, you should be able to state: 1. possible common infectious diseases based on the signs. 2. probable etiologic agent. 3. possible means of transmission. 4. expected clinical and pathologic signs. 5. methods for confirming the diagnosis. 6. recommendations for treatment, control and prevention. 7. significance of the disease. V-9025 - GUINEA PIGS: Infectious Diseases 3 1. Series Laboratory Animal Medicine and Sciences - Series ll 2. Program title Guinea Pigs: Infectious Diseases This autotutorial session provides an overview of the more common infectious diseases of the guinea pig. It was designed to assist in teaching basic information about infectious diseases of guinea pigs to veterinary students, technicians and other biomedical science students. Clinical syndromes, gross and histopathologic lesions, as well as methods of diagnosis, treatment and control of the more significant infectious diseases of guinea pigs are examined. 3. Objectives Given a guinea pig or a description of a guinea pig assumed to be diseased, you should be able to state: • possible common infectious diseases based on the signs. • probable etiologic agent. • possible means of transmission. • expected clinical and pathologic signs. • methods for confirming the diagnosis. • recommendations for treatment, control and prevention. • significance of the disease. 4. Overview In this program, we will address the various types of infectious disease in guinea pigs, including: • bacterial • fungal • viral • chlamydial • parasitic 5. Section title BACTERIAL AND FUNGAL DISEASES Bacterial and fungal agents are responsible for some of the most significant diseases of guinea pigs. 6. Bacterial diseases Several primary respiratory diseases of the guinea pig are of bacterial origin, with Bordetella bronchiseptica and Streptococcus pneumoniae being the most important. Other infectious agents listed on this image act as opportunistic invaders in traumatized tissue (Streptococcus zooepidemicus), and contribute to enteric disease (Clostridium piliforme and Salmonella spp) and dermatitis (Trichophyton mentagrophytes). 4 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 7. Pneumonic lung Pneumonic lungs, seen here as the dark-colored tissue, may have one or more areas of consolidation and hemorrhage. Bordetella bronchiseptica, Streptococcus pneumoniae, or other bacteria frequently cause pneumonia in guinea pigs. Affected animals may have no clinical signs, or exhibit nasal discharge, sneezing, dyspnea, weight loss, or sudden death. Increased incidence of abortion and stillbirths may accompany respiratory signs in epizootics. 8. Bordetella Bordetella bronchiseptica is a small gram negative rod. Incidence of Bordetella bronchiseptica infection in guinea pigs may be high because many animal species such as rabbits, dogs and cats carry the organism in nonclinical infections. For this reason, rabbits and guinea pigs should not be housed together. Transmission between animals is by direct contact, aerosol, or contaminated fomites. Asymptomatic carriers frequently occur. 9. Bronchopneumonia Lesions include rhinitis, tracheitis and pulmonary consolidation. Typical histopathologic lesions of purulent bronchitis and bronchopneumonia with large accumulations of neutrophils and intraluminal debris (arrow) are shown here. 10. Head tilt Otitis media may also occur with Bordetella infections. Severe otitis media may be accompanied by head tilt (torticollis). V-9025 - GUINEA PIGS: Infectious Diseases 3 11. Radiograph One may detect suppurative otitis media through radiographic examination of the tympanic bulla, as illustrated in this unilaterally affected animal (arrow). Otitis also may be detected as cloudiness in the tympanic membrane visualized with an otoscope. Diagnosis of bordetellosis is based on clinical signs, histopathologic lesions and recovery of the organism from the respiratory exudate. Pearl-like colonies grown on blood agar reach maximal size in 72 hours. 12. Bordetella Treatment of Bordetella bronchiseptica infection is often unrewarding. Antibiotics of choice include chloramphenicol, sulfamethazine and trimethoprim-sulfa. Autogenous or commercial bacterins may be used to prevent overt disease but may not prevent the carrier state. Effective prevention includes good husbandry and maintenance of a closed Bordetella free colony. Guinea pigs carrying the organism are generally not suitable for research because of the tendency to break with clinical disease when stressed. 13. Antibiotic toxicity Antibiotics may suppress clinical signs but usually do not eliminate the organism and fatal antibiotic-induced enterocolitis is always a concern in treating guinea pigs. Antibiotics implicated include penicillin, aminoglycoside, erythromycin, clindamycin, lincomycin, chlonetracycline, oxytetracycline, bacitracin, and dihydrostreptomycin. 14. S. pneumoniae Fibrinopurulent pericarditis, shown here, can be caused by Streptococcus pneumoniae. It may be accompanied by fibrinous pleuritis and bronchopneumonia. Streptococcus pneumoniae is an alpha-hemolytic, gram positive coccus that tends to occur in pairs. Mortality is high in enzootics. Clinical signs are similar to those seen in other bacterial pneumonias. Otitis media, metritis and other suppurative processes may occur. Transmission of Streptococcus pneumoniae is by aerosol or direct contact with diseased or asymptomatic carrier guinea pigs, rats or humans. 6 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 15. Recovering strep Streptococcus pneumoniae may be recovered by culture of 2 affected tissues on blood agar incubated in 10% C0 at 37° C. Identification of the organism is confirmed by the appearance of a distinct zone of growth inhibition around an optochinimpregnated disk on a blood agar plate. Diagnosis also may be made by examining the stained smears of exudate for pairs and chains of gram positive cocci. Treatment may be approached the same as for Bordetella infections. Control involves good husbandry, stress reduction and elimination of carriers from the colony. Although no cases of transmission from laboratory animals to human have been documented, it should be noted that Streptococcus pneumoniae can cause respiratory and meningeal disease in humans, particularly in elderly and immunocompromised persons. 16. Lymphadenitis Cervical lymphadenitis is caused most commonly by Streptococcus zooepidemicus. Other Streptococcus spp and Streptobacillus moniliformis are rarely implicated. The organism may be an asymptomatic inhabitant of the upper respiratory track that opportunistically invades damaged mucosa. Bite wounds or aerosol spread onto mucosal surfaces are the primary modes of transmission. Cervical lymph nodes become swollen, abscess and often rupture. 17. Lymph node Lymph nodes progress to encapsulated abscesses filled with yellow-white purulent exudate. Diagnosis is based on clinical signs and culture of the organism from lesions. Treatment may include drainage and lavage of lesions and antibiotic therapy with chloramphenicol or trimethoprim-sulfa. Control is accomplished by culling affected animals prior to rupture of lesions and separating new stock from an existing colony. Killed bacterins are not effective in preventing disease, but scratch inoculation of the oral mucosa with Streptococcus zooepidemicus recovered from swine stimulates immunity. V-9025 - GUINEA PIGS: Infectious Diseases 3 18. Infected liver This image shows the multiple gray-white foci often found in the liver of guinea pigs with Tyzzer's disease. Overt disease is characterized by a rough coat, lethargy, watery diarrhea and death. Necropsy examination may reveal lesions in the intestine, including edema, hemorrhage, ulceration and fluid contents. The liver may be enlarged. 19. C. piliforme The causative agent, Clostridium piliforme is a gram negative, PAS-stain positive, spore forming, obligate intracellular rod. Infection occurs by fecal-oral transmission of spores that may persist for years in the environment. The prevalence of Tyzzer's disease in guinea pig populations is not known. Carriers of the disease are probably widespread, but overt disease is typically seen only in immunocompromised or stressed individuals. 20. C. piliforme Inflammatory infiltration is apparent in the lamina propria of the intestine (on the left) and frequently in the liver (on the right). 21. Intestine and liver Definitive diagnosis is made by identifying 'pick-up sticks' arrangements of organisms in Giemsa or Warthin-Starry silver stained tissues (as seen here at the arrows), serologic testing for antibody to Clostridium piliforme, or inoculating weanling gerbils with feces from affected animals. Gerbils are very sensitive to Clostridium piliforme and rapidly develop illness and diarrhea, as well as the typical hepatic lesions associated with Tyzzer's disease. Treatment may be attempted, but is usually unrewarding. Suppression of signs is sometimes accomplished with chloramphenicol. Outbreaks can be controlled by strict sanitation, appropriate cleaning of the environment and reducing environmental stress. 8 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 22. Salmonella Salmonella typhimurium and other Salmonella spp will infect guinea pigs. Sporadic outbreaks with high mortality are the rule, with guinea pigs becoming most susceptible around parturition, weaning, or other times of physiologic stress. Clinical signs of salmonellosis include anorexia, rough haircoat, lethargy, weight loss, soft feces, reproductive inefficiency and abortion. 23. Transmission Many animal species harbor Salmonella organisms which are shed intermittently in the feces. Transmission is fecal-oral; organisms often are introduced in contaminated foods such as fresh fruits and vegetables, or through the water supply. 24. Fluid filled GI tract Necropsy findings may include gas and fluid contents in the gastrointestinal tract as seen here. Enlargement of the liver, spleen and lymphoid tissues may also be found. 25. Spleen Necrotic foci may be found throughout the spleen, liver and lymphatic tissues. Clinical signs, necropsy findings and histopathologic lesions suggest a diagnosis of salmonellosis. Confirm the diagnosis by culture of feces and lesioned lymph nodes in enrichment broth and selective media. Treatment is not generally recommended, because the carrier state may be induced. V-9025 - GUINEA PIGS: Infectious Diseases 3 26. Management Culture-positive animals should be removed from the colony. The room and equipment should be disinfected and restocked with clean animals. This approach risks failure to detect all carriers by culture and subsequent reappearance of disease. In some cases complete eradication followed by disinfection and restocking may be necessary. To avoid an outbreak, rigid sanitation and quarantine procedures should be observed and new arrivals and human caretakers screened. Salmonella spp are infective to humans and may cause serious disease in children and immunocompromised individuals. 27. Dermatophytosis This animal has dermatophytosis and may also show some signs of barbering. Trichophyton mentagrophytes is the most common cause of dermatophytosis (ringworm) in the guinea pig and rabbit. While clinical infections are uncommon, asymptomatic carriers are abundant. Spores may be found in hair, bedding and soil. Animals become susceptible when stressed and may develop irregular alopecia with occasional crusting over the dorsal body surface. 28. Fungal spores Microscopic examination of a skin scraping or histologic skin sections may reveal fungal spores (as seen here) and hyphae. (A few drops of potassium hydroxide (KOH) may help clear the image of unwanted debris.) Culture of hair shafts from a lesion onto dermatophyte test media may also be used to confirm a diagnosis. Topical antifungal creams used daily for 2 to 4 weeks, or griseofulvin at 25 mg/kg daily in the water for 14 days or 20mg/kg in feed for 25 days, are generally effective treatments. Prevention of outbreaks may be accomplished by strict sanitation, screening suspect animals and culling affected animals. Trichophyton mentagrophytes is infective to humans and other animal species. 29. Mastitis Mastitis is common in lactating sows. Milk provides an excellent media for the growth of bacteria that may invade when young traumatize the teats. Multiple agents have been implicated, including Pasteurella spp, Klebsiella spp, Staphylococcus spp, Streptococcus spp and others. Mammary glands become warm, enlarged and hyperemic, as illustrated on the image. The milk may appear bloody; depression and even death may follow. Diagnosis is based on clinical signs. Treatment includes hot packs and antibiotic therapy. Surgical resection of the affected tissue may need to be considered if it becomes necrotic or gangrenous. Young should be weaned immediately. The best prevention for mastitis involves proper sanitation and maintenance of a clean environment for lactating sows. 10 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 30. Section title VIRAL AND CHLAMYDIAL DISEASES Some viral and chlamydial disease agents are listed on this image, but they are of limited importance. Few if any clinical signs are seen, yet researchers should be aware that studies may be complicated by the presence of subclinical disease. 31. Conjunctivitis Overt signs of inclusion body conjunctivitis, as seen in this image, are found primarily in one to three week old guinea pigs. Spontaneous resolution of the disease is complete by four weeks of age in most animals. Chlamidia psittaci, the infective agent, is transmitted via feces, saliva and nasal secretions; infections may be spread by direct contact or aerosol. The disease is enzootic in many guinea pig colonies. Erythematous conjunctiva, serous ocular discharge and photophobia are found in affected animals. 32. Conjunctival scraping Definitive diagnosis is made from microscopic examination of scrapings of the conjunctival mucosa, shown here, and identification of cytoplasmic inclusion bodies (arrow) in epithelial cells. Serologic screening by fluorescent antibody test is also available. Most cases resolve without treatment, but ophthalmic ointments may be used to make the animal more comfortable during the acute phase of disease. No cases of human chlamydial infection have been attributed to guinea pigs, yet this organism should still be considered a potential human pathogen. 33. Salivary gland Cytomegalovirus is a common, mostly subclinical, pathogen of guinea pigs. Immunosuppressed and stressed animals will sometimes exhibit overt signs such as swelling of the salivary glands and tenderness in the affected region. The agent, a herpes virus, resides in the nerve cell bodies of the trigeminal nerve and replicates in the salivary gland ductal epithelium during times of stress. Transmission occurs through shedding of the virus in saliva and, possibly, transplacentally. Cytomegalovirus trophism for placental tissues also leads to late gestational abortion due to placental necrosis. Diagnosis is made by histopathologic examination of submaxillary salivary gland for periductal lymphoid aggregates, large eosinophilic intranuclear inclusion bodies (large arrow) and very small intracytoplasmic inclusion bodies (small arrow). Indirect fluorescent antibody serologic testing is available. No treatment other than stress reduction is usually attempted. Virus research and reproductive studies may be complicated by this disease. V-9025 - GUINEA PIGS: Infectious Diseases 3 34. LCM Lymphocytic choriomeningitis (LCM) is caused by an RNA Arenavirus. No naturally occurring cases have been reported in guinea pigs. However, guinea pigs inoculated with contaminated biologicals have contracted the disease. Wild mice are the natural reservoir; they shed virus in saliva and urine that may infect other rodent species via direct contact, aerosol spread, fomites, or mechanical vectors. 35. Posterior paralysis Usually there are no clinical signs, but rear limb paralysis and CNS disturbances from meningitis have been reported in guinea pigs with LCM. Necropsy examination may reveal liver and spleen enlargement, while histopathologic examination reveals lymphoid infiltrates around meningeal blood vessels and glomerulonephrosis. Diagnosis should be confirmed by ELISA and IFA serologic screening; mouse antibody production (MAP) testing may also be done. Eradication of the virus from an infected colony is complicated by intrauterine transmission; the entire colony should be euthanatized. Introduction of the virus into a colony can be prevented by screening colonies with serologic tests and eliminating access of wild animal vectors. Tumors and other biologic materials to be introduced into guinea pigs should be screened for LCM. LCM is capable of causing mild to severe illness in humans. 36. Lymphosarcoma A type C Oncornavirus is the etiologic agent responsible for the leukemia found in aged guinea pigs. Cavian leukemia virus is widespread and usually transmitted transplacentally, remaining dormant in the animal until aging or stress trigger disease expression. Lymphadenopathy, rough hair coat and ascending paralysis are associated with the clinical disease syndrome. 37. Hepatomegaly Hepatomegaly, splenomegaly and diffuse lymphadenopathy are found frequently in guinea pigs with viral-induced leukemia/ lymphosarcoma. Enlarged organs appear mottled and light in color. Anemia and leukocytosis are often present. 12 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 38. Lymphoid infiltration Microscopic examination of these lesioned organs reveals the presence of lymphoblastic cellular infiltrates obliterating the architecture of tissues. Diagnosis can be made in a living animal by examining a peripheral blood smear for disproportionately large numbers of lymphoblasts. No treatment or preventive measures are recommended. 39. Other viral agents Positive titers to Sendai virus, pneumonia virus of mice (PVM) and simian virus 5 (SV 5) are frequently detected in apparently healthy guinea pigs. These Paramyxoviruses have the ability to briefly replicate in the guinea pig, allowing it to become a potential reservoir of virus for murid rodent species. Colony contamination and potential research interference is reduced by maintaining strict separation of animal species. 40. Adenovirus Although incidence is low in the United States, cavian Adenovirus should not be overlooked. Pneumonia with a high rate of morbidity is associated with this virus in other areas of the world. Serologic testing for Adenovirus is not available in the U.S., but a presumptive diagnosis may be made based on the presence of basophilic intranuclear inclusion bodies within respiratory epithelial cells of animals with pneumonia or necrotizing tracheitis. 41. Coronavirus A Coronavirus-like virion has been found in enteric tissues of young guinea pigs with acute wasting and diarrhea syndrome. Enteric Coronavirus infection is associated with acute and often serious disease in young rabbits, pigs, dogs, cats and cattle. It may prove to be a significant disease in guinea pigs as well. 42. Section title PARASITES Many parasites are known to infect guinea pigs, but as a rule, parasites are more a problem in hobby and breeding colonies than in the research setting. In this program, we present information on the major ectoparasites, protozoans and nematodes. 43. Ectoparasites Common ectoparasites of the guinea pig include the mites Trixicaris caviae and Chirodiscoides caviae, as sell as the lice, Gliricola porcelli and Gyropus ovalis. 44. Alopecia Acariasis in guinea pigs is primarily associated with two species of mite, Trixacaris caviae and Chirodiscoides caviae. Both mites are found in greater frequency in pet and breeding colonies than in research colonies. Mild to severe alopecia may be seen, as illustrated in the image. Trixacaris caviae, a burrowing mite, poses a significant threat to the health of a guinea pig colony. Infestations can interfere with research by affecting the general health and well-being of the animals and by providing vectors for other infectious diseases. Trixicaris caviae tend to distribute on the neck, shoulders, lower abdomen, and inner thighs, whereas Chirodiscoides caviae distribute more randomly. V-9025 - GUINEA PIGS: Infectious Diseases 3 45. Trixacaris caviae Trixacaris caviae, a sarcoptid mange mite, burrows through the keratin layer of the epidermis causing alopecia, crusting, and an intense pruritus that may lead to self mutilation, debility and death. 46. Chirodiscoides caviae Chirodiscoides caviae, a fur mite, may cause few or no clinical signs in infested animals. Mites are transmitted by direct contact with the host, animal bedding, or hair and debris. 47. Mite in keratin layer Antemortem diagnosis is made by preparing skin scrapings with IO% KOH and identifying the mites microscopically (as illustrated in the previous two images) or by examining the fur with a magnifying glass. Trixacaris caviae may be identified postmortem in the keratin layer of sections of the skin. Pelts may be placed on a dark background and examined with a dissecting microscope for fur mite migration. 48. Treatments Reported treatments for acariasis include pyrethroid flea powder dusts, lime sulfur dips and injections with ivermectin. While the safety and efficacy of ivermectin in guinea pigs for external parasite control has not been established in controlled studies, it has been anecdotally reported to be effective in guinea pigs. Colony outbreaks can be prevented by placing clean animals into a clean environment and eliminating contamination by wild rodents. In the event of an outbreak, infected animals should be separated and treated while the premises are thoroughly cleaned. Allow the area to remain empty for 3 weeks before reintroducing animals, in order to ensure the death of any mites remaining in the environment. 14 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 49. Lice Guinea pig lice, Gliricola porcelli (left) and Gyropus ovalis (right) are chewing lice that cause occasional alopecia and mild pruritus with heavy infestations; Gliricola porcelli is seen more commonly. Lice are spread by direct contact with the host or contaminated bedding. 50. Lice and nits This image illustrates low power magnification via a dissecting microscope. Magnification of the pelt adjacent to lesions or around the neck will reveal nits attached to the hair shaft. Pelts may be cooled and examined for migration of the parasites toward the hair tips. Treatment is the same as that for mites. Rooms should be scrubbed and fumigated before restocking with clean animals. New arrivals should be quarantined and examined for lice prior to placement in existing colonies. 51. Protozoans The protozoan Cryptosporidium sp is a major cause of enteric disease in guinea pigs. Intestinal colonization may lead to lethargy, rough hair coat, weight loss and diarrhea. 52. "Greasy Coat' Affected individuals often have a 'greasy" appearance, as illustrated by the matted hair along the midline in the accompanying image. Subclinical infection is common. Transmission occurs through ingestion of mature oocysts in contaminated food, water and fomites. Necropsy examination may reveal hyperemia of the small intestine, serosal edema of the cecum, watery ingesta and general emaciation in affected animals. V-9025 - GUINEA PIGS: Infectious Diseases 3 53. Intestine Cryptosporidium sp preferentially colonizes the anterior portion of the ileum, where fusion, atrophy and metaplasia of villous epithelium are seen. Eosinophilic infiltration of the lamina propria frequently accompanies other changes. Diagnosis may be confirmed by identification of the organism within epithelial cells (arrow). Mucosal scrapings or smears of fresh feces examined with phase contrast microscopy may be the best method of diagnosis; fecal flotation is generally unrewarding. 54. Management No effective treatment for Cryptosporidium sp is available, but addition of 0.2% sulfamethazine to the water supply may suppress outbreaks. Oocysts can be destroyed by cleaning the environment with 5% ammonia. Prevention of the disease is best approached by improving sanitation and avoiding contact of guinea pigs with other susceptible species. Cryptosporidium sp is not species specific and is potentially zoonotic to other animal species and humans. 55. Protozoans Balantidium caviae, a relatively nonpathogenic protozoan, is commonly found in fecal smears (left), or on histopathologic examination of the gastrointestinal tract. Eimeria caviae (right), is found in the colon and may cause overt clinical coccidiosis in infected colonies. Eimeria sp may be diagnosed antemortem by fecal flotation, or postmortem by colonic mucosal scrapings or histological examination of the colon. 56. Protozoans Tritrichomonas spp (left) and Giardia sp (right) also are frequently incidental findings. In this image, tritichomonads are found in large numbers in the lumen, along with ingesta and the larger Entamoeba organisms; Tritrichomonas spp are oval to pear-shaped structures that stain pink in this preparation. These organisms may contribute to occasional diarrhea in host animals. Episodes of diarrhea, if they occur, may be controlled with metronidazole at 30-60 mg/kg PO once daily for 5 days. Enteric protozoans are not typically species specific. Protozoans should be considered zoonotic agents with potential to infect humans. 16 LABORATORY ANIMAL MEDICINE AND SCIENCE - SERIES II 57. Klossiella cobaye A nonpathogenic renal coccidian, Klossiella cobaye, is viewed as an incidental finding in histopathic sections of kidney. Schizonts may be found in the epithelial cells of the renal tubules. 58. Paraspidodera The only nematode commonly associated with guinea pigs is the roundworm, Paraspidodera uncinata. Adult worms (left) dwell in the cecum and shed eggs (right) into the feces. Eggs are then ingested in contaminated food or water. Infections are usually considered insignificant. Typical thick-shelled, ascarid-like eggs are identified on fecal flotations. Piperazine has been reported to be an effective treatment. Ivermectin injected SC at 0.2 mg/kg may be used, but again, the safety and efficacy of this product in guinea pigs has not been established in controlled studies. Improving environmental sanitation and increasing the frequency of bedding changes helps to eliminate the parasite by reducing the spread of eggs to other animals and decreasing reinfection of treated animals. 59 . ACLAM credits This program was developed for the American College of Laboratory Animal Medicine. C. W. McPherson, DVM Chair J. E. Harkness, DVM J. F. Harwell, Jr., DVM J. M. Linn, DVM A. F. Moreland, DVM G. L. Van Hoosier, Jr., DVM L. Dahm, MS Instructional development, editing and production management provided by L. Dahm, MS, and Bob J. McGough, BS Medical Communication. Illustrations, graphics and imagery produced by Dale Leuthold, BA, and Joseph Wilmhoff, BIS. Guide production by Pamela Young and Barbara Macfadden, BA. The development of this program was supported by a grant from the Department of Agriculture: National Agricultural Library Grant 59-32U4-9-45 61. HSCER credits Produced by the Health Sciences Center for Educational Resources University of Washington Seattle WA 98195 2000 V-9025 - GUINEA PIGS: Infectious Diseases 3 BIBLIOGRAPHY Feldman, S. H., I. A. Richardson, and F. L. Clubb, Jr. 1990. Necrotizing viral bronchopneumonia in guinea pigs. Lab. Anim. Sci. 40: 82- 83. Harkness, J. E., and J. E. Wagner. 1989. The biology of rabbits and rodents, 3rd ed. Lea and Febiger, Philadelphia Jaax, G. P., N. K. Jaax, 1. P. Petrai, K. D. Corcoran, and A. P. Vogel. 1990. Coronavirus-like virions associated with a wasting syndrome in guinea pigs. Lab. Anim. Sci. 40: 375-378. Manning, P. J., J. E. Wagner, and J. E. Harkness. 1984. Biology and diseases of guinea pigs, p. 149- 182. In J. G. Fox, B. J. Cohen, and F. M. Loew (ed.), Laboratory animal medicine. Academic Press, Inc., Orlando, Fla. Schnurrenberger, P. R., and W. T. Hubbert 1981. An outline of the zoonoses. The Iowa State Press, Ames, Iowa. Wolff, A., S. K. Shanker, C. L. Gibbs, Jr., and D. C. Gajdusek. Cervical lymphoblastic leukemia in an aged guinea pig. Lab. Anim. Sci. 38: 83-84. ACKNOWLEDGMENTS The authors express appreciation to the following individuals who contributed Kodachrome images to this program: J. E. Wagner, College of Veterinary Medicine, University of Missouri. Howard Wilson, University of Missouri, for assistance in photography and image preparation for this program. Previous contributors to the ACLAM image series. This project was supported in part by Grants RR 00471 and RR 07004 from the National Institutes of Health, Bethesda Md.
Pages to are hidden for
"GUINEA PIGS Infectious Diseases"Please download to view full document