Table 69-4.
DIAGNOSIS OF INTESTINAL PATHOGENS OF DOGS AND CATS
| Pathogen | Method of Diagnosis |
|---|---|
| Helminths | |
| Ascarids (Toxocara, Toxascaris leonina) | Routine fecal flotation for ova |
| Hookworms (Ancylostoma) | Routine fecal flotation for ova |
| Whipworms (Trichuris vulpis) | Routine fecal flotation for ova; fenbendazole trial |
| Tapeworms (Taenia, Dipylidium caninum) | Fecal proglottids or flotation for ova |
| Strongyloides | Fecal sediment or Baermann test for larvae |
| Others (flukes) | Fecal zinc sulfate centrifugation-flotation for ova |
| Protozoa | |
| Coccidia (Isospora) | Fecal flotation for oocysts |
| Cryptosporidium spp. | Microplate ELISA, direct immunofluorescence, PCR, Sheather's flotation |
| Giardia | Fecal zinc sulfate centrifugation-flotation for cysts; fecal ELISA or IFA; duodenal wash for trophozoites; fenbendazole trial |
| Tritrichomonas foetus | Fecal wet smear for trophozoites; InPouch TF culture; PCR |
| Entamoeba histolytica | Fecal wet smear for trophozoites |
| Balantidium coli | Fecal wet smear for trophozoites |
| Viruses | |
| Canine parvovirus | Fecal ELISA (SNAP-Parvo Test) for viral antigen (see Chapter 14) |
| Feline panleukopenia virus | Signs, leucopenia (see Chapter 14) |
| Canine coronavirus | Fecal EM, virus culture, PCR (see Chapter 14) |
| Feline enteric coronavirus and FIP | Signs, serology, fecal EM, PCR, biopsies (see Chapter 10) |
| Rotaviruses | Fecal EM, virus culture, PCR (see Chapter 14) |
| Astrovirus | Fecal EM, PCR (see Chapter 14) |
| Canine distemper virus | Signs (see Chapter 13) |
| Retroviruses (FeLV, FIV) | FeLV antigen test (ELISA, IFA); FIV antibody test (see Chapters 8, 9) |
| Rickettsia | |
| Salmon poisoning (Neorickettsia helminthoeca) | Operculated trematode eggs in feces; rickettsia in lymph node cytology (see Chapter 17) |
| Bacteria | |
| Salmonella | Fecal culture |
| Campylobacter jejuni | Fecal microscopy and culture |
| Yersinia enterocolitica, Y. pseudotuberculosis | Fecal culture |
| Bacillus piliformis (Tyzzer's disease) | Biopsy (gut, liver) for filamentous bacteria; mouse inoculation |
| Mycobacterium spp. | Acid-fast bacteria in cytology/biopsy; culture, PCR (see Chapter 19) |
| Clostridium perfringens, C. difficile | ELISA-based fecal enterotoxin assays; PCR |
| Enteropathogenic Escherichia coli (?) | Fecal culture and toxin assays |
| Fungi | |
| Histoplasma capsulatum | Fungi in biopsies/cytologies; serology (see Chapter 20) |
| Pythium, Zygomycetes | Pythium ELISA; poorly septate hyphae in biopsies (Chapters 20, 40) |
| Others (Candida albicans, Aspergillus, etc.) | Yeast or hyphae in biopsies; fungal culture (see Chapters 20, 40) |
| Algae (Prototheca) | Unicellular algae in cytology or biopsy; fecal culture (Sabouraud's) |
ELISA, enzyme-linked immunosorbent assay; EM, electron microscopy; FeLV, feline leukemia virus; FIP, feline infectious peritonitis; FIV, feline immunodefi-ciency virus; IFA, immunofluorescent antibody; PCR, polymerase chain reaction test; Rx, therapeutic response.