Efficacy of ronidazole for treatment of feline Tritrichomonas foetus infection

OBJECTIVES: To determine the efficacy of ronidazole (RDZ), tinidazole (TDZ), and metronidazole (MDZ) against Tritrichomonas foetus in vitro and of RDZ for treatment of feline naturally occurring or experimentally induced T. foetus infection. ANIMALS: A cat naturally infected with T. foetus infection and diarrhea. Ten specific-pathogen-free (SPF) kittens. PROCEDURE: RDZ, TDZ, and MDZ were tested for activity against 3 different feline isolates of T. foetus in vitro. RDZ then was administered to a naturally infected cat at 10 mg/kg PO q24h for 10 days. SPF kittens were infected orogastrically with feline T. foetus and treated with either placebo or RDZ (10 mg/kg PO q12h for 14 days). Cats with relapsing infection or those receiving placebo were treated subsequently with RDZ (either 30 or 50 mg/kg PO q12h for 14 days). Feces were examined for T. foetus by direct microscopy, culture, and polymerase chain reaction (PCR) testing weekly. RESULTS: Both RDZ and TDZ killed T. foetus at concentrations >0.1 microg/mL in vitro. In the naturally infected cat, RDZ abolished diarrhea and T. foetus infection for 85 days after treatment, at which time infection and diarrhea relapsed. Retreatment with RDZ eradicated diarrhea and T. foetus infection for over 407 days. In experimentally induced infection, RDZ at 10 mg/kg caused initial improvement, but infection relapsed in all 5 cats 2 to 20 weeks after treatment. At 30 or 50 mg/kg, 10/10 cats were negative for T. foetus infection for follow-up durations of 21 to 30 weeks after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of RDZ at 30 to 50 mg/kg q12h for 14 days resolved diarrhea and eradicated infection (on the basis of polymerase chain reaction [PCR] testing) in 1 naturally infected cat and 10 experimentally inoculated cats receiving a different isolate of T. foetus.     

Outcome of cats with diarrhea and Tritrichomonas foetus infection

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. DESIGN: Prospective study. 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.     

Experimental infection of cats with Tritrichomonas foetus.

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) were assessed. 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.     

Pharmacokinetics of tinidazole in dogs and cats

Pharmacokinetics of tinidazole in dogs and cats after single intravenous (15 mg/kg) and oral doses (15 mg/kg or 30 mg/kg) were studied in a randomized crossover study. Tinidazole was completely absorbed at both oral dose levels in cats and dogs. Peak tinidazole concentration in plasma was 17.8 micrograms/ml in dogs and 22.5 micrograms/ml in cats after 15 mg/kg p.o. The oral dose of 30 mg/kg resulted in peak levels of 37.9 micrograms/ml in dogs and 33.6 micrograms/ml in cats. The apparent total plasma clearance of the drug was about twofold higher in dogs than in cats, resulting in an elimination half-life that was twice as long in cats (8.4 h) as in dogs (4.4 h). The apparent volume of distribution was 663 ml/kg in dogs and 536 ml/kg in cats. Therapeutic plasma drug concentrations higher than the MIC values of most tinidazole-sensitive bacteria were achieved for 24 h in cats and for 12 h in dogs after a single oral dose of 15 mg/kg. From the pharmacokinetic standpoint tinidazole seems to be well-suited to clinical use in small animal practice.     

Concentrations of tinidazole in gingival crevicular fluid and plasma in dogs after multiple dose administration

Tinidazole 15 mg/kg was administered to eight Beagle dogs with gingivitis or periodontitis twice daily for 3 days. Tinidazole concentrations in blood and gingival crevicular fluid (GCF) were measured 1,3,6 and 9 h after the morning dose each day. The concentration of tinidazole was determined by high performance liquid chromatography (HPLC). The mean concentration of tinidazole in GCF for each dog ranged from 6.05 to 9.32 αg/mL at different time points after the first dose, and on the first day the highest concentration was observed 6 h after the drug administration. Tinidazole concentrations were 34 ± 4%-72 ± 9% (mean ± SEM) of simultaneous plasma concentration. At steady-state, on the third treatment day, the mean tinidazole concentrations in GCF ranged from 6.68 to 13.1 μg/mL, i.e. 44 ± 6%-75 ± 25% of the corresponding concentrations in plasma. Tinidazole concentration in GCF exceeded the MIC values for putative path-ogenic periodontal bacteria and it is concluded that, when indicated, tinidazole could be used for chemotherapy of periodontitis in dogs.     

Ronidazole pharmacokinetics after intravenous and oral immediate-release capsule administration in healthy cats

Ronidazole (RDZ) is an effective treatment for feline Tritrichomonas foetus infection, but has produced neurotoxicity in some cats. An understanding of the disposition of RDZ in cats is needed in order to make precise dosing recommendations. Single-dose pharmacokinetics of intravenous (IV) RDZ and immediate-release RDZ capsules were evaluated. A single dose of IV RDZ (mean 9.2mg/kg) and a 95mg immediate-release RDZ capsule (mean 28.2mg/kg) were administered to six healthy cats in a randomized crossover design. Plasma samples were collected for 48 h and assayed for RDZ using high pressure liquid chromatography (HPLC). Systemic absorption of oral RDZ was rapid and complete, with detection in the plasma of all cats by 10 min after dosing and a bioavailability of 99.64 (±16.54)%. The clearance of RDZ following IV administration was 0.82 (±0.07) ml/kg/min. The terminal half-life was 9.80 (±0.35) and 10.50 (±0.82) h after IV and oral administration, respectively, with drug detectable in all cats 48h after both administrations. The high oral bioavailability of RDZ and slow elimination may predispose cats to neurotoxicity with twice-daily administration. Less frequent administration should be considered for further study of effective treatment of T foetus-infected cats.     

Determination of the in vitro susceptibility of feline tritrichomonas foetus to 5 antimicrobial agents

BACKGROUND: The nitroimidazole, ronidazole, has been demonstrated to have in vitro and in vivo activity against the protozoan Tritrichomonas foetus in cats. The purpose of this study was to evaluate the in vitro susceptibility of feline T. foetus isolates obtained from naturally infected cats to 5 antimicrobial agents and to compare the in vitro time kill of ronidazole and metronidazole. HYPOTHESIS: We hypothesized that nitroimidazoles have in vitro activity against T. foetus, whereas furazolidone, omeprazole, and paromomycin do not. ANIMALS: Fecal specimens were cultured from 4 naturally infected Bengal cats with a history of T. foetus-associated diarrhea. METHODS: A 24-hour susceptibility assay was performed on all 4 isolates for the 5 antimicrobial agents. A time-kill microdilution method was performed on 2 isolates for metronidazole and ronidazole. RESULTS: Paromomycin and omeprazole showed no in vitro effect at concentrations < or = 80 microg/mL. There was no significant difference in 24-hour susceptibilities among metronidazole, ronidazole, and furazolidone. In addition, only the results of the highest concentration tested (80 microg/mL) and concentrations of 1.25 and 2.5 microg/mL revealed significant differences in the rate of trophozoite killing, with ronidazole having a faster reduction in trophozoite survival. CONCLUSIONS AND CLINICAL IMPORTANCE: Time-kill assays demonstrated ronidazole had a higher lethal activity compared with metronidazole. These findings contrast with a previously published report and may reflect strain variation, different methodologies, or both. The lack of clinical response seen with metronidazole administration to treat feline trichomoniasis may not reflect inherent resistance but rather in vivo events involving drug distribution and pharmacokinetics.     

Identification of Pentatrichomonas hominis in feline fecal samples by polymerase chain reaction assay

Pentatrichomonas hominis is considered to be a commensal protozoan of the vertebrate digestive tract. On the basis of light microscopic examination of feces, some investigators presumptively identified P. hominis as a causative agent of feline diarrhea. However, molecular identification of P. hominis infection in the cat has not been reported. Another trichomonad, Tritrichomonas foetus, is recognized as an intestinal pathogen in cats and often presumptively diagnosed on the basis of the presence of trichomonads in diarrheic feces. It is of importance to determine if cats are natural hosts for P. hominis, as the presence of this organism could result in inaccurate assumption of T. foetus infection. In this study, we used a species-specific PCR assay to identify P. hominis 18S rRNA genes in fecal samples collected from a convenience population of cats in which a high prevalence of T. foetus infection had been previously identified (cat show) or suspected (submitted for T. foetus diagnostic testing). The prevalence of T. foetus infection in these samples was 31% and 28.6%, respectively. P. hominis infection was identified by PCR of DNA extracted from feces of five cats (1.9% and 2.1% of fecal samples, respectively). All cats in which P. hominis was identified were also infected with T. foetus. PCR identification of P. hominis infection in the cat should facilitate future studies to determine the pathogenicity of this species and enable differentiation of P. hominis from other known or as-yet unidentified species of trichomonads that may infect cats.     

Histologic features associated with tritrichomonas foetus-induced colitis in domestic cats

Tritrichomonas foetus is a venereal pathogen of naturally bred cattle. In domestic cats, T. foetus colonizes the colon, resulting in chronic, large-bowel diarrhea. The infection is prevalent among young, densely housed cats, and there is no effective treatment. To the authors' knowledge, the characteristic microscopic lesions of T. foetus infection in naturally infected cats have not been described. The aim of the study reported here was to characterize the histologic changes in the colon of seven cats with T. foetus infection and chronic diarrhea. All cats were 1 year old or younger (mean, 6.7 +/- 1.7 months), and a diagnosis of T. foetus infection was made on the basis of direct fecal smear examination (five cats), fecal culture in InPouch TF medium (four cats), single-tube nested polymerase chain reaction (PCR) analysis of DNA extracted from feces (two cats), or observation of trichomonads in sections of colon followed by PCR confirmation on DNA extracted from paraffin-embedded tissue (two cats). The presence of colonic trichomonads was the most diagnostic histologic feature. Organisms were identified in all cats, but in only 24 of 43 (56%) sections of colon. Trichomonads were generally present in close proximity to the mucosal surface and less frequently in the lumen of colonic crypts. The presence of colonic trichomonads was consistently associated with mild-to-moderate lymphoplasmacytic and neutrophilic colitis, crypt epithelial cell hypertrophy, hyperplasia and increased mitotic activity, loss of goblet cells, crypt microabscesses, and attenuation of the superficial colonic mucosa. In two of the cats, histologic lesions were more severe and were associated with invasion of trichomonads into the lamina propria and/or deeper layers of the colon.     

Detection of Tritrichomonas foetus and Pentatrichomonas hominis in intestinal tissue specimens of cats by chromogenic in situ hybridization

In this retrospective study 102 cats were analyzed for the presence of trichomonads in intestinal tissue sections using chromogenic in situ hybridization (CISH). Two intestinal trichomonad species are described in cats: Pentatrichomonas hominis and Tritrichomonas foetus. While P. hominis is considered a mere commensal, T. foetus has been found to be the causative agent of feline large-bowel diarrhea. For the detection of both agents within intestinal tissue CISH assays using three different probes were performed. In the first CISH run a probe specific for all relevant members of the order Trichomonadida (OT probe) was used. In a second CISH run all positive samples were further examined on three consecutive tissue sections using the OT probe, a probe specific for the family of Tritrichomonadidae (Tritri probe) and a newly designed probe specifically detecting P. hominis (Penta hom probe). In total, four of the 102 cats were found to be positive with the OT probe. Thereof, one cat gave a positive reaction with the P. hominis probe and three cats were positive with the T. foetus probe. All Trichomonas-positive cats were pure-bred and between 8 and 32 weeks of age. In one cat positive for T. foetus large amounts of parasites were found in the gut lumen and invading the intestinal mucosa. The species of the detected trichomonads were confirmed by polymerase chain reaction and nucleotide sequencing of a part of the 18S ribosomal RNA gene. In this study, the usefulness of CISH to detect intestinal trichomonads within feline tissue samples was shown. Additionally, the specific detection of P. hominis using CISH was established. Generally, it was shown that CISH is well suited for detection and differentiation of trichomonosis in retrospective studies using tissue samples.     

Effects of lufenuron treatment in cats on the establishment and course of Microsporum canis infection following exposure to infected cats

OBJECTIVE: To determine effects of lufenuron treatment in cats on the establishment and course of Microsporum canis infection following exposure to infected cats. DESIGN: Experimental trial. ANIMALS: 24 healthy juvenile domestic shorthair cats. PROCEDURE: 8 cats were given lufenuron PO (133 mg/cat/mo, equivalent to a dose of 100 to 130 mg/kg [45 to 59 mg/lb] at the beginning of the study and 25 to 35 mg/kg [11 to 16 mg/lb] at the end of the study), and 8 were given lufenuron SC (40 mg every 6 months). The remaining 8 were used as untreated control cats. After 4 months, cats were challenged by the introduction of cats with mild, experimentally induced M canis infection into the rooms where cats were housed. Extent of resulting infections in the na?ve cats was monitored for 22 weeks by physical examination and fungal culture. RESULTS: All lufenuron-treated and control cats became infected with M canis. Cats treated with lufenuron had significantly lower infection scores, compared with control cats, during the early weeks following exposure, and there was a more prolonged initial progression phase of the infection. Once infections reached peak intensity, they resolved over similar periods in lufenuron-treated and control cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that oral or SC administration of lufenuron to cats, at the dosages used and under the conditions of this study, did not prevent establishment of dermatophytosis following exposure to infected cats. Infection was established more slowly among cats treated with lufenuron, but once established, infection resolved in approximately the same amount of time in lufenuron-treated as in control cats.     

Penetration of tinidazole into the gingival crevicular fluid in dogs

Tinidazole was administered as a single oral dose of 15 mg kg-1 to 12 dogs, and its concentration in the plasma and gingival crevicular fluid (GCF) was measured at one and two hours by high performance liquid chromatography. Tinidazole was detectable in GCF in five dogs at one hour (6.8 +/- 2.6 micrograms ml-1) and in six dogs at two hours (9.2 +/- 1.4 micrograms ml-1) and in all plasma samples. In those animals with no detectable tinidazole in GCF, either the concentration of tinidazole in plasma was low or the volume of the GCF sample was insufficient for determination. The observed tinidazole levels in GCF exceeded the minimal inhibitory concentration values for most anaerobic oral bacteria.     

Survival of a feline isolate of Tritrichomonas foetus in water, cat urine, cat food and cat litter

Feline intestinal trichomoniasis caused by Tritrichomonas foetus is associated with large bowel diarrhea in cats from many parts of the world. It has long been recognized as an economically important sexually transmitted disease that causes early abortion in cattle. Isolates of T. foetus from cattle are infectious for the large intestine of cats and isolates of T. foetus from cats are infectious for the reproductive system of cattle. The parasite is maintained by fecal-oral transmission in cats. The present study was conducted to examine the survival of a feline isolate of T. foetus, AUTf-12, under various conditions that are relevant to fecal-oral transmission in cats. Trophozoites were grown in TYM medium and then exposed to water, cat urine, dry cat food, canned cat food, clumping cat litter, or filter paper for various lengths of time and then re-cultured in TYM medium. Trophozoites survived exposure to distilled or tap water for 30 but not 60 min, while they survived for at least 180 min in urine. Trophozoites survived for 30 min on dry cat food but survived for 120-180 min in canned cat food. No survival of trophozoites was observed on cat litter but trophozoites survived for 15 min when placed on filter paper. Our results indicate that T. foetus can survive and be potentially infectious in water, urine, dry cat food and canned cat food.     

Documentation of In Vivo and In Vitro Aerobic Resistance of Feline Tritrichomonas foetus Isolates to Ronidazole

Background: The mainstays of treatment for clinically important trichomonad infections are the 5‐nitroimidazoles. Metronidazole resistance of feline Tritrichomonas foetus is presumed because of common treatment failure, and tinidazole does not consistently eradicate infection. To date, ronidazole is the only drug demonstrated as effective for treatment of cats infected with T. foetus. Objective: To document in vivo treatment failure and identify underlying causes and in vitro conditions of resistance of feline T. foetus to ronidazole. Animals: Two intact male Abyssinians failing ≥5 courses of treatment with increasing doses of 5‐nitroimidazole drugs. An intact male Abyssinian documented to clear infection after treatment with a single course of ronidazole. Methods: T. foetus isolates were cultured from feces and tested in vitro for susceptibility to ronidazole under aerobic and anaerobic culture conditions. A urogenital nidus of T. foetus infection was investigated by culture, polymerase chain reaction, or immunohistochemical testing of urogenital specimens. Results: Resistance to ronidazole under aerobic conditions was uniquely identified in T. foetus isolated from cats with well‐documented treatment failure. Treatment failure could not be attributed to reinfection, inappropriate treatment protocol, or presence of a urogenital nidus of infection. Conclusions and Clinical Importance: Clinical resistance to metronidazole, low efficacy of tinidazole, and present documentation of in vivo and in vitro resistance to ronidazole in some cats are consistent with a high level of cross resistance of feline T. foetus to 5‐nitroimidazole drugs. Current lack of alternative drugs with clinical efficacy against feline T. foetus suggests that active investigation of other treatment approaches is warranted.     

Clinical evaluation of the efficacy of inoculating cattle with a vaccine containing Tritrichomonas foetus.

To test the efficacy of a polyvalent Tritrichomonas foetus vaccine, 130 nulliparous heifers were randomly assigned to either receive the test T foetus vaccine or to serve as nonvaccinated controls. The polyvalent test vaccine consisted of a Campylobacter fetus/Leptospira canicola-grippotyphosa-hardjo-icterohaemorrhagiae-pamona bacterine containing 5 x 10(7) killed T foetus/dose. The polyvalent control vaccine consisted of the aforementioned formulation without T foetus. Heifers were administered 2 doses of control or experimental vaccine at 3-week intervals. Heifers were bred to T foetus-infected bulls and their conception and pregnancy rates were determined throughout gestation. In addition, serum samples were analyzed to determine induced concentrations of antitrichomonal antibodies and vaginal secretions were sampled to determine T foetus infection rates in control and vaccinated animals. One week after each of the 15-day breeding periods, 60% (6 of 10) of tested vaccinates and 80% (8 of 10) of tested control animals were T foetus culture-positive. The mean duration of infection of vaccinates was 3.8 weeks (+/- 7.5 days), compared with 5.4 weeks (+/- 7.5 days) of infection for control heifers. All vaccinates developed increased immunofluorescence and serum neutralizing antibody titers following the first immunization, and had additional increases of at least fourfold in response to the second injection. In contrast, no consistent increase in immunofluorescence or serum neutralizing antibodies was observed in control animals. Conception rates were 89.2% for vaccinates and 85.9% for control animals 30 days after breeding and 80 to 90% of these remained pregnant 60 days after breeding.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of loperamide hydrochloride on experimental diarrhea and gastrointestinal myoelectrical activity in calves

The antidiarrheal action of loperamide hydrochloride was tested against diarrhea experimentally induced in calves by intraduodenal infusion of castor oil or hypertonic solution of mannitol. The motility of 4 levels of the digestive tract (abomasum, jejunum, and proximal and spiral loops of the colon) was concomitantly recorded, using an electromyographic technique. Loperamide hydrochloride given per os at 0.4 mg/kg or intraduodenally or subcutaneously at 0.1 mg/kg 1 hour before mannitol or castor oil was given delayed diarrhea. Loperamide hydrochloride given alone orally at a dosage of 0.4 mg/kg did not modify the motility pattern of the digestive tract. Intraduodenally administered loperamide hydrochloride (0.1 mg/kg) increased the frequency of the cyclic activity of the jejunum, whereas subcutaneously administered loperamide hydrochloride at the same dose selectively inhibited the motility of the jejunum. Intraduodenal infusion of mannitol was followed by a disruption of the cyclic activity of the jejunum, and this effect was not antagonized by loperamide hydrochloride, whatever the route of administration. Castor oil infusion was not accompanied with changes in gastrointestinal motility. These results indicate that loperamide hydrochloride is active against an experimentally induced diarrhea in calves and that this action is not mediated through an effect on the digestive motility, at least monitored by this electromyographic technique.     

Is AZT/3TC therapy effective against FIV infection or immunopathogenesis?

In vitro and in vivo prophylactic and therapeutic efficacy of AZT/3TC treatment was evaluated against feline immunodeficiency virus (FIV) infection. In vitro studies utilized FIV-infected peripheral blood mononuclear cells (PBMCs) or FIV-infected T-cell lines treated with AZT (azidothymidine) alone, 3TC alone, or AZT/3TC combination and tested for anti-FIV activity and drug toxicity. AZT/3TC combination had additive to synergistic anti-FIV activities in primary PBMC but not in chronically infected cell lines. In vivo studies consisted of four treatment groups (n=15) of SPF cats receiving AZT/3TC combination (5-75 mg/kg/drug PO BID for 8 or 11 weeks) and one control group (n=9) receiving oral placebo. Group I (n=6, 150 mg/kg/drug/day) was treated starting 3 days pre-FIV inoculation, whereas Group II (n=3, 150 mg/kg/drug/day) and Group III (n=3, 100 mg/kg/drug/day) treatments were simultaneous with FIV inoculation. Group IV treatment (n=3, 100 mg/kg/drug/day) was initiated 2 weeks post-FIV inoculation. All cats were monitored for drug toxicity and FIV infection. Eighty-three percent of cats in Group I and 33% of cats in Groups II and III were completely protected from FIV infection. A significant delay in infection and antibody seroconversion was observed in all unprotected cats from Groups I, II and III. Group IV cats had only a slight delay in FIV antibody seroconversion. Adverse drug reactions (anemia and neutropenia) were observed at high doses (100-150 mg/kg/drug/day) were reversible upon lowering the dose (20 mg/kg/drug/day). In contrast, AZT/3TC treatment had no anti-FIV activity in chronically infected cats. Furthermore, severe clinical symptoms caused by adverse drug reactions were observed in some of these cats. Overall, AZT/3TC treatment is effective for prophylaxis but not for therapeutic use in chronically FIV-infected cats.     

Critical evaluation of taeniacidal antibiotic S15-1 (SQ 21, 704) for removal of natural tapeworm infections in dogs and cats

The new taeniacidal antibiotic S15-1 (SQ 21,704) was evaluated against naturally occuring infections of Taenia pisiformis in 53 dogs, Dipylidium caninum in 35 dogs, T taeniaformis in 18 cats, and D caninum in 33 cats. It all instances, the compound was administered in gelatine capsules in a single oral dose. The doses tested were between and 200 mg/kg of body weight in dogs and between 15 and 45 mg/kg in cats. In dogs, doses of 25 mg/kg and greater were 100% effective against T pisiformis, whereas a dose of 50 mg/kg was necessary to clear D caninum. In cats, a single oral dose of 22.5 mg/kg was 100% efficacious against T taeniaeformis, and a single dose of 45 mg/kg (the largest dose tested) clearly seven of eight cats of D caninum. The efficacy was limited to tapeworms only; there was no efficacy against nematodes. The antibiotic was well tolerated by both species with no drug-related vomiting or other side-effects observed.     

Use of a commercially available culture system for diagnosis of Tritrichomonas foetus infection in cats

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. DESIGN: Prospective study. 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 degrees C [98.6 or 77.0 degrees 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 degrees C, cultures yielded positive results in 24 hours; organisms remained viable for 1 to 6 days, and bacterial overgrowth was common. At 25 degrees 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 < or = 0.1 g of freshly voided feces and cultured at 25 degrees C.