An update on three important protozoan parasitic infections in cats: cryptosporidiosis, giardiasis, and tritrichomoniasis - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


An update on three important protozoan parasitic infections in cats: cryptosporidiosis, giardiasis, and tritrichomoniasis
Our knowledge of these protozoan parasites in cats continues to expand. Here's what you need to know about diagnosing these infections and treating affected patients.



1. Xiao L, Bern C, Limor J, et al. Identification of 5 types of Cryptosporidium parasites in children in Lima, Peru. J Infect Dis 2001;183:492-497.

2. Pedraza-Diaz S, Amar C, Iversen AM, et al. Unusual Cryptosporidium species recovered from human faeces: first description of Cryptosporidium felis and Cryptosporidium 'dog type' from patients in England. J Med Microbiol 2001;50:293-296.

3. Morgan UM, Weber R, Xiao L, et al. Molecular characterization of Cryptosporidium isolates obtained from human immunodeficiency virus-infected individuals living in Switzerland, Kenya, and the United States. J Clin Microbiol 2000;38:1180-1183.

4. Pieniazek NJ, Bornay-Llinares FJ, Slemenda SB, et al. New cryptosporidium genotypes in HIV-infected persons. Emerg Infect Dis 1999;5:444-449.

5. Scorza AV, Burnett R, Black WC IV, et al. Molecular and phylogenetic characterization of Cryptosporidium from cats and dogs (abst), in Proceedings. Int Giardia Cryptosporidium Conf 2004.

6. Marquardt WC, Demaree RS, Grieve RB. The intestinal coccidian. In: Parasitology and vector biology. 2nd ed. San Diego, Calif: Hartcourt/Academic Press, 2000;29-35.

7. Parasitology Research, Division of Biology, Kansas State University. Basic biology of Cryptosporidium. Available at: Accessed Feb 21, 2006.

8. Scorza AV, Brewer MM, Lappin MR. Polymerase chain reaction for the detection of Cryptosporidium spp. in cat feces. J Parasitol 2003;89:423-426.

9. Kirkpatrick CE. Feline giardiasis: a review. J Small Anim Pract 1986;27:69-80.

10. Monis PT, Thompson RCA. Cryptosporidium and Giardia-zoonoses: fact or fiction? Infect Genet Evol 2003;3:233-244.

11. Kirkpatrick CE, Farrell JP. Feline giardiasis: observations on natural and induced infections. Am J Vet Res 1984;45:2182-2188.

12. Gookin JL, Levy MR, Law JM, et al. Experimental infection of cats with Tritrichomonas foetus. Am J Vet Res 2001;62:1690-1697.

13. Gookin JL, Birkenheuer AJ, St. John V, et al. Molecular characterization of trichomonads from feces of dogs with diarrhea (abst), in Proceedings. Am Coll Vet Intern Med 2005.

14. Gookin JL, Copple C, Papich M, et al. Efficacy of ronidazole in vitro and in vivo for treatment of feline Tritrichomonas foetus infection (abst), in Proceedings. Am Coll Vet Intern Med 2005.

15. Iseki M. Cryptosporidium felis sp.n. (Protozoa: Eimeririna) from the domestic cat. Jpn J Parasitol 1979;5:285-307.

16. Lindsay DS, Zajac AM. Cryptosporidium infections in cats and dogs. Compend Contin Educ Pract Vet 2004;26:864-874.

17. McReynolds CA, Lappin MR, Ungar B, et al. Regional seroprevalence of Cryptosporidium parvum-specific IgG antibodies of cats in the United States. Vet Parasitol 1999;80:187-195.

18. Hill SL, Cheney JM, Taton-Allen GF, et al. Prevalence of enteric zoonotic organisms in cats. J Am Vet Med Assoc 2000;216:687-692.

19. Spain CV, Scarlett JM, Wade SE, et al. Prevalence of enteric zoonotic agents in cats less than 1 year old in central New York State. J Vet Intern Med 2001;15:33-38.

20. Scorza AV, Lappin MR. Detection of Cryptosporidium spp. in feces of cats and dogs in the United States by PCR assay and IFA (abst). J Vet Intern Med 2005;19:437.

21. Gookin JL, Stebbins ME, Hunt E, et al. Prevalence of and risk factors for feline Tritrichomonas foetus and Giardia infection. J Clin Microbiol 2004;42:2707-2710.

22. Thompson RCA. The zoonotic potential of Cryptosporidium. In: Thompson RCA, Armson A, Ryan UM, eds. Cryptosporidium: from molecules to disease. New York, NY: Elsevier, 2003;113-119.

23. Kirkpatrick CE, Laczac JP. Giardiasis in a cattery. J Am Vet Med Assoc 1985;187:161-162.

24. Gookin JL, Breitschwerdt EB, Levy MG, et al. Diarrhea associated with trichomonosis in cats. J Am Vet Med Assoc 1999;215:1450-1454.

25. Carey CM, Lee H, Trevors JT. Biology, persistence and detection of Cryptosporidium parvum and Cryptosporidium hominis oocysts. Water Res 2004;38:818-862.

26. Gookin JL, Nordone SK, Argenzio RA. Host responses to Cryptosporidium infection. J Vet Intern Med 2002;16:12-21.

27. Poonacha KB, Pippin C. Intestinal cryptosporidiosis in a cat. Vet Pathol 1982;19:708-710.

28. Lappin MR, Dowers K, Edsell D, et al. Cryptosporidiosis and inflammatory bowel disease. Feline Pract 1997;25:10-13.

29. Monticello TM, Levy MG, Bunch SE, et al. Cryptosporidiosis in a feline leukemia virus-positive cat. J Am Vet Med Assoc 1987;191:705-706.

30. Goodgame RW, Kimball K, Ou CN, et al. Intestinal function and injury in acquired immunodeficiency syndrome-related cryptosporidiosis. Gastroenterology 1995;108:1075-1082.

31. Burgess DE, et al. Cytotoxic and hemolytic effects of Tritrichomonas foetus on mammalian cells. Infect Immun 1990;58:3627-3632.

32. Yaeger MJ, Gookin JL. Histologic features associated with Tritrichomonas foetus-induced colitis in domestic cats. Vet Pathol 2005;42:797-804.

33. Asahi H, Koyama T, Arai H, et al. Biological nature of Cryptosporidium spp. isolated from a cat. Parasitol Res 1991;77:237-240.

34. Arai H, Fukuda Y, Hara T, et al. Prevalence of Cryptosporidium infection among domestic cats in the Tokyo metropolitan district. Jpn J Med Sci Biol 1990;43:7-14.

35. Goodwin MA, Barsanti JA. Intractable diarrhea associated with intestinal cryptosporidiosis in a domestic cat also infected with feline leukemia virus. J Am Anim Hosp Assoc 1990;26:335-337.

36. Lappin MR, Ungar B, Brown-Hahn B, et al. Enzyme-linked immunosorbent assay for the detection of Cryptosporidium parvum IgG in the serum of cats. J Parasitol 1997;83:957-960.

37. Keith CL, Radecki SV, Lappin MR. Evaluation of fenbendazole for treatment of Giardia infection in cats concurrently infected with Cryptosporidium parvum. Am J Vet Res 2003;64:1027-1029.

38. Perez Trot G, Asanovic J, Petetta L. Resolucion de un caso complejo de diarrhea en una gata. Rev Med Vet 2002;84:73-74.

39. Brightman AH, Slonka GF. A review of five clinical cases of giardiasis in cats. J Am Anim Hosp Assoc 1976;12:492-497.

40. Nesvadba VJ. Giardiasis in a cat. Kleintier-Praxis 1979;24:177-179.

41. Brown RR, Elston TH, Evans L, et al. American Association of Feline Practitioners 2003 Report on Feline Zoonoses. Compend Contin Educ Pract Vet 2003;25:936-965.

42. Marks SL, Hanson TE, Melli AC. Comparison of direct immunofluorescence, modified acid-fast staining, and enzyme immunoassay techniques for detection of Cryptosporidium spp. in naturally exposed kittens. J Am Vet Med Assoc 2004;225:1549-1553.

43. Lappin MR, Jensen WA, Taton-Allen G. Comparison of Zn SO4 centrifugation, a fecal antigen assay, and an immunofluorescent antigen assay for diagnosis of giardiasis in cats (abst). J Vet Intern Med 2002;345.

44. Caccio SM, De Giacomo M, Pozio E. Sequence analysis of the beta-giardin gene and development of a polymerase chain reaction-restriction fragment length polymorphism assay to genotype Giardia duodenalis cysts from human faecal samples. Int J Parasitol 2002;32:1023-1030.

45. Leib MS, Zajac AM. Giardiasis in dogs and cats. Vet Med 1999;94:793-802.

46. Lappin MR, Calpin J. Laboratory diagnosis of protozoal diseases. In: Greene CE, ed. Infectious diseases of the dog and cat. Philadelphia, Pa: WB Saunders Co, 1998;437-441.

47. Zimmer JF, Burrington DB. Comparison of four techniques of fecal examination for detecting canine giardiasis. J Am Anim Hosp Assoc 1986;22:161-167.

48. Payne PA, Ridley RK, Dryden MW, et al. Efficacy of a combination febantel-praziquantel-pyrantel product, with or without vaccination with a commercial Giardia vaccine, for treatment of dogs with naturally occurring giardiasis. J Am Vet Med Assoc 2002;220:330-333.

49. Cirak VY, Bauer C. Comparison of conventional coproscopical methods and commercially coproantigen ELISA kits for the detection of Giardia and Cryptosporidium infections in dogs and cats. Berl Munch Tierarztl Wochenschr 2004;117:410-413.

50. Gookin JL, Foster DM, Poore MF, et al. Use of a commercially available culture system for diagnosis of Tritrichomonas foetus infection in cats. J Am Vet Med Assoc 2003;222:1376-1379.

51. Gookin JL, Birkenheuer AJ, Breitschwerdt EB, et al. Single-tube nested PCR for detection of Tritrichomonas foetus in feline feces. J Clin Microbiol 2002;40:4126-4130.

52. Farthing MJG. Clinical aspects of human cryptosporidiosis. Contrib Microbiol 2000;6:50-74.

53. Elitok B, Elitok OM, Pulat H. Efficacy of azithromycin dihydrate in treatment of cryptosporidiosis in naturally infected dairy calves. J Vet Intern Med 2005;19:590-593.

54. Hewitt RG, Yiannoutsos CT, Higgs ES, et al. Paromomycin: no more effective than placebo for treatment of cryptosporidiosis in patients with advance human immunodeficiency virus infection. Clin Infect Dis 2000;31:1084-1092.

55. Barr SC, Jamrosz GF, Hornbuckle WE, et al. Use of paromomycin for treatment of cryptosporidiosis in a cat. J Am Vet Med Assoc 1994;205:1742-1743.

56. Gookin JL, Riviere JE, Gilger BC, et al. Acute renal failure in four cats treated with paromomycin. J Am Vet Med Assoc 1999;215:1821-1823.

57. Diaz E, Mondragon J, Ramirez E, et al. Epidemiology and control of intestinal parasites with nitazoxanide in children in Mexico. Am J Trop Med Hyg 2003;68:384-385.

58. Ortiz JJ, Ayoub A, Gargala G, et al. Randomized clinical study of nitazoxanide compared to metronidazole in the treatment of symptomatic giardiasis in children from Northern Peru. Aliment Pharmacol Ther 2001;15:1409-1415.

59. Hawrelak J. Giardiasis: pathophysiology and management. Altern Med Rev 2003;8:129-142.

60. Shatto NL. Feline giardiasis (a case report). Vet Med Small Anim Clin 1981;76:1297-1298.

61. Zimmer JF. Treatment of feline giardiasis with metronidazole. Cornell Vet 1987;77:383-388.

62. Scorza AV, Lappin MR. Metronidazole for the treatment of feline giardiasis. J Feline Med Surg 2004;6:157-160.

63. Groman R. Metronidazole. Compend Contin Educ Pract Vet 2000;22:1104-1107.

64. Lindsay DS, Blagburn BL. Antiprotozoan drugs. In: Adams HR, Veterinary pharmacology and therapeutics. 8th ed. Ames: Iowa State University Press, 2001;993-994.

65. Caylor KB, Cassimatis MK. Metronidazole neurotoxicosis in two cats. J Am Anim Hosp Assoc 2001;37:258-262.

66. Harris JC, Plummer S, Lloyd D. Antigiardial drugs. Appl Microbiol Biotechnol 2001;57:614-619.

67. Schwartz RD, Donoghue AR, Baggs RB, et al. Evaluation of the safety of fenbendazole in cats. Am J Vet Res 2000;61:330-332.

68. Plumb DC. Veterinary drug handbook. 5th ed. Ames, Iowa: Blackwell Publishing, 2005;1126-1128.

69. Stokol T, Randoph JF, Nachbar S, et al. Development of bone marrow toxicosis after albendazole administration in a dog and cat. J Am Vet Med Assoc 1997;210:1753-1756.

70. Scorza AV, Radecki SV, Lappin MR. Efficacy of a combination of febantel, pyrantel, and praziquantel for the treatment of kittens experimentally infected with Giardia species. J Feline Med Surg 2006;8:7-13.

71. Barr SC, Bowman DD, Frongillo MR, et al. Efficacy of a drug combination of praziquantel, pyrantel pamoate, and febantel against giardiasis in dogs. Am J Vet Res 1998;59:1134-1136.

72. Olson ME, Hannigan C, Gaviller R, et al. The use of a Giardia vaccine as an immunotherapeutic agent in dogs. Can Vet J 2001;42:865-868.

73. Stein JE, Radecki SV, Lappin MR. Efficacy of Giardia vaccination in the treatment of giardiasis in cats. J Am Vet Med Assoc 2003;222:1548-1551.

74. Okhuysen PC, Chappell CL, Crabb JH, et al. Virulence of three distinct Cryptosporidium parvum isolates for healthy adults. J Infect Dis 1999;180:1275-1281.

75. Barr SC. Giardiasis. In: Greene CE, ed. Infectious diseases of the dog and cat. 3rd ed. New York, NY: Elsevier, 2005;736-742.

76. Anderson KA, Brooks AS, Morrison AL, et al. Impact of Giardia vaccination on asymptomatic Giardia infections in dogs at a research facility. Can Vet J 2004;45:924-930.

77. Glaser CA, Safrin S, Reingold A, et al. Association between Cryptosporidium infection and animal exposure in HIV-infected individuals. J Acquir Immune Defic Syndr Hum Retrovirol 1998;17:79-82.

78. The Centers for Disease Control and Prevention, Division of Parasitic Disease. Preventing cryptosporidiosis: a guide to water filters and bottled water. Available at: Accessed Feb 21, 2006.


Click here