Objective—To evaluate the efficacy of and optimize a
commercially available culture system for sensitive
and specific in-clinic culture of Tritrichomonas foetus
from cat feces.
Sample Population—Samples of freshly voided
feces from 117 purebred cats and pure cultures of
T foetus obtained from a cat with chronic diarrhea.
Procedure—Optimal conditions for use of the culture
system, such as quantity of fecal inoculum (0.025 to
0.2 g) and cultivation temperature (25 or 37°C [98.6 or
77.0°F]), were determined. Specificity of the system
was examined by attempted culture of Giardia lamblia
and Pentatrichomonas hominis. Sensitivity of the system
to detect T foetus was determined by inoculation
of culture system pouches with serially diluted T foetus suspensions
with and without feces.
Results—Detection limit of the culture system was 1
and 1,000 T foetus organisms without and with feces
from cats, respectively. Optimal fecal inoculum was
< 0.1 g of feces. At 37°C, cultures yielded positive results
in 24 hours; organisms remained viable for 1 to 6 days,
and bacterial overgrowth was common. At 25°C, cultures
yielded positive results in 1 to 11 days; organisms were
long-lived, and bacterial overgrowth was uncommon.
Neither G lamblia or P hominis survived in the culture system.
Conclusions and Clinical Relevance—The culture
system was sensitive and specific for culture of
T foetus in feces of cats. Performance was optimal
when test kits were inoculated with ≤ 0.1 g of freshly
voided feces and cultured at 25°C. (J Am Vet Med Assoc
Objective—To determine the long-term outcome of
cats infected with Tritrichomonas foetus and identify
treatment and management strategies influencing
resolution of infection or associated diarrhea.
Sample Population—26 cats with T foetus-associated
diarrhea at least 22 months prior to the study.
Procedure—A standardized survey regarding clinical
course and management was administered to owners
of cats with T foetus infection and associated diarrhea.
Fecal samples were obtained from each cat; the
presence of T foetus was assessed via microscopic
examination of smears, culture in commercial media,
and polymerase chain reaction amplification of T foetus rDNA
involving species-specific primers.
Results—Survey responses were obtained from owners
of all 26 cats. Twenty-three cats had complete resolution
of diarrhea a median of 9 months after onset.
Analysis of fecal samples obtained from 22 cats
revealed persistent T foetus infection in 12, with a
median of 39 months after resolution of diarrhea.
History of implementation of a dietary change, treatment
with paromomycin, or higher numbers of cats in
the household was associated with significantly longer
duration of time to resolution of diarrhea.
Conclusions and Clinical Relevance—Results suggested
chronic T foetus-associated diarrhea in most
cats is likely to resolve spontaneously within 2 years
of onset. Chronic infection with T foetus(without clinical
signs) after resolution of diarrhea appears to be
common. Although often temporarily effective in
decreasing severity of diarrhea, attempts to treat cats
with T foetus infection may result in prolongation of
time to resolution of diarrhea. (J Am Vet Med Assoc
Objective—To determine the efficacy of tinidazole for treatment of cats with experimentally induced Tritrichomonas foetus infection.
Animals—8 specific-pathogen-free kittens.
Procedures—Tinidazole was tested for activity against a feline isolate of T foetus in vitro. Kittens were infected orogastrically with the same isolate and treated or not with tinidazole (30 mg/kg, PO, q 24 h for 14 days). Amoxicillin was administered 28 weeks after completion of tinidazole administration to induce diarrhea. Feces were repeatedly tested for T foetus by use of PCR assay and microbial culture for 33 weeks.
Results—Tinidazole killed T foetus at concentrations ≥ 10 μg/mL in vitro. In experimentally induced infection, tinidazole administered at 30 mg/kg decreased T foetus below the limit of molecular detection in 2 of 4 cats. Recrudescent shedding of T foetus, as elicited by amoxicillin-induced diarrhea, was diminished in cats that received prior treatment with tinidazole.
Conclusions and Clinical Relevance—Although tinidazole decreased the detection of T foetus and treated cats were resistant to later efforts to incite the infection, inability of tinidazole to eradicate infection in many cats poses a serious impediment to the drug’s effectiveness in practice.
Objective—To determine whether infection with
Tritrichomonas foetus causes diarrhea in specific pathogen-free or Cryptosporidium coinfected cats.
Animals—4 cats with subclinical cryptosporidiosis
(group 1) and 4 specific-pathogen-free cats (group 2).
Procedure—Cats were infected orogastrically with an
axenic culture of T foetus isolated from a kitten with
diarrhea. Direct microscopy and protozoal culture of
feces, fecal character, serial colonic mucosal biopsy
specimens, and response to treatment with nitazoxanide
(NTZ; group 1) or prednisolone (groups 1 and 2)
Results—Infection with T foetus persisted in all cats
for the entire 203-day study and resulted in diarrhea
that resolved after 7 weeks. Group-1 cats had an earlier
onset, more severe diarrhea, and increased number
of trichomonads on direct fecal examination, compared
with group-2 cats. Use of NTZ eliminated shedding
of T foetus and Cryptosporidium oocysts, but
diarrhea consisting of trichomonad-containing feces
recurred when treatment was discontinued.
Prednisolone did not have an effect on infection with
T foetus but resulted in reappearance of
Cryptosporidium oocysts in the feces of 2 of 4 cats.
During necropsy, T foetus was isolated from contents
of the ileum, cecum, and colon. Tritrichomonas foetus
organisms and antigen were detected on surface
epithelia and within superficial detritus of the cecal
and colonic mucosa.
Conclusions and Clinical Relevance—After experimental
inoculation in cats, T foetus organisms colonize
the ileum, cecum, and colon, reside in close contact
with the epithelium, and are associated with transient
diarrhea that is exacerbated by coexisting cryptosporidiosis
but not treatment with prednisolone.
(Am J Vet Res 2001;62:1690–1697)