Rollingmoss, our Sophers had diahrrea with blood in it for months and even though she was treated for coccidia the diahrrea hung on for close to 8 months if not longer. I remember the vet testing her for T Foetus and giardia several times. I might consider running one more test just to make sure before you go down the road of the meds for T Foetus. I did find this info also:
http://www.hcvma.org/notes/SpeakerNotesToddTams.pdfTritrichomonas foetus
Tritrichomonas foetus is a recently identified enteric protozoan of cats. It causes chronic large bowel diarrhea
(loose stools, presence of blood and mucus, straining to defecate), and is most commonly seen in young cats
that have resided in densely populated housing such as catteries and shelters. The diarrhea may be
intermittent or persistent. Loose stool may dribble out (lack of control) and the anal area may become
edematous. The organism is present in the ileum, cecum, and colon as a trophozoite. The organism does not
encyst, so trophozoites are the only recognized stage. Infection in feral cats and healthy cats appears to be
uncommon.
Until 2005 no effective treatment had been identified. The diarrhea eventually resolves over a period of time
(months up to one to two years), but currently ronidazole is the recommended therapy, and tinidazole may be
effective in some cases. It is important that an accurate diagnosis be made so that clients can be counseled
appropriately, i.e., they should expect that their cat(s) will continue to have abnormal stools for some period of
time. Also, it is not uncommon for cats to be co-infected with Giardia, so a thorough evaluation for parasites is
important (run a minimum of one zinc sulfate with centrifugation and a Giardia antigen test).
Tritrichomonas foetus is commonly mistaken for Giardia trophozoites on direct smear exam. All trichomonads
posses three to five anterior flagella, an undulating membrane, and a recurrent flagellum attached to the edge of
the undulating membrane. All flagella originate from an anterior basal body. An axostyle extends the length of
the trichomonad and extends posteriorly. A cyst stage is not known for this genus. Video clips showing both
Giardia and Tritrichomonas trophozoites are available on the North Carolina State University website cited in the
reference list below.
Definitive diagnosis can be made in some cases by direct smear of fresh feces in saline and examined at 200 to
400x magnification. Sensitivity is low, however, for diagnosis by direct smear (only 14% in one study), so
results can often be false negative. To increase the chance of finding Tritrichomonas trophozoites on direct
smear, it is recommended that multiple direct smears be done on the same day. Whenever possible, a cat with
suggestive signs should be hospitalized for part or all of a day so that each fecal sample that is passed can be
examined quickly via direct saline smear.
Tritrichomonas foetus can also be grown from feces via incubation at 37 degrees C in Diamond’s medium. A
commercially available culture system is also available and is recommended for use in clinical practice (InPouch
TF, Biomed Diagnostics Inc., San Jose, CA). The medium in InPouch does not support the growth of Giardia
species or Pentatrichomonas hominis so presence of organisms is consistent with T. foetus. PCR is the most
sensitive means for confirming a diagnosis. In one study of 36 cats with T. foetus infection, 20/36 were positive
on the InPoch TF test and 34/36 were positive on PCR. Details on the PCR assay can be reviewed on the
North Carolina State website.
Recent studies at North Carolina State University showed that ronidazole is effective (30 mg/kg BID for 14
days). Ronidazole is a nitroimidazole antimicrobial that is not licensed for any use in the U.S. The medication is
not readily available in the United States, but several compounding pharmacies are preparing to make the drug
available. The drug has mutagenic properties, so it must be compounded the same way as chemotherapy
drugs. Several sources for ronidazole include WestLab Pharmacy in Gainesville, FL and Diamondback Drugs
in Scottsdale, AZ (
www.diamondbackdrugs.com). We have had several cats experience mild neurological side
effects to ronidazole, similar to what can be seen with metronidazole. These resolved upon discontinuation of
the drug. The dose of 30 mg/kg should not be exceeded. It is important that an accurate diagnosis be made so
that clients can be counseled appropriately, i.e., they should expect that their cat(s) will continue to have
abnormal stools for some period of time until definitive treatment can be administered.
An alternative drug which can be tried is tinidazole. This is also a nitroimidazole antimicrobial. A dose of 15-30
mg/kg SID can be tried. It should be safe and may or may not be effective. Studies are ongoing.
