Metronidazole for the treatment of feline giardiasis

There are several drugs available for the treatment of giardiasis in cats, including metronidazole. The purpose of this study was to determine whether metronidazole benzoate administered at a dose of 25 mg/kg, orally, twice a day for 7 days lessens or eliminates Giardia cyst shedding in cats with chronic infection. Twenty-six, adult, laboratory-reared cats were used in this study. Sixteen cats had been inoculated orally with cysts of a human Giardia sp. isolate and had completed a Giardia vaccine study in one animal holding room. The other ten cats were infected with the same Giardia sp. presumably by contamination from the adjacent room where the Giardia vaccine study cats were located. From each cat, a fecal sample was collected within 1 week of the start of treatment and then every 2 to 4 days for 15 days after treatment was completed. Fecal samples were analyzed for the presence of Giardia cysts using a commercially available direct immunofluorescence test (IFA). Clinical signs of drug toxicity were not detected during the study.     

Efficacy of vaccination in preventing giardiasis in calves

The objective of this study was to evaluate the efficacy of a vaccine in the prevention of Giardia duodenalis infection in calves. Six 2-week old calves were vaccinated subcutaneously with a sonicated G. duodenalis trophozoite vaccine. Six 2-week old control calves received a subcutaneous injection of sterile phosphate-buffered-saline mixed with adjuvant. Injections were repeated after 28 days. Eleven days after the second injection, calves were challenged orally with 1x10(5) purified G. duodenalis cysts from a naturally infected calf. Throughout the study, fecal samples were collected at regular intervals and examined for the presence of G. duodenalis cysts. Blood samples were collected weekly until G. duodenalis challenge and bi-weekly following challenge. Calves were euthanized 14 days after challenge and G. duodenalis trophozoites within the small intestines were enumerated. Serum antibody titers were significantly higher in vaccinated compared to non-vaccinated calves. Vaccinated calves tended to excrete more G. duodenalis cysts in their feces than non-vaccinated calves. The number of trophozoites in the small intestine was not different between vaccinated and non-vaccinated calves. Changes consistent of moderate enteritis were found in the intestines of one vaccinated and one non-vaccinated calf. Despite a serological immune response following vaccination, this vaccine was not efficacious in preventing giardiasis or reducing cyst shedding in calves.     

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

OBJECTIVE: To determine efficacy of treatment with a combination febantel-praziquantel-pyrantel product, with or without vaccination with a commercial Giardia vaccine, in dogs with naturally occurring giardiasis. DESIGN: Prospective trial. ANIMALS: 16 Beagles naturally infected with Giardia duodenalis. PROCEDURES: During phase 1, 6 dogs were treated with the parasiticide for 3 days (4 were also vaccinated). Four weeks later, all 6 dogs were treated with the parasiticide again for 5 days and were bathed and moved to clean cages after the last treatment (phase 2). Nine dogs were treated with the parasiticide for 3 (n = 4) or 5 (5) days and bathed and moved to clean cages after the last treatment (phase 3). Fecal samples were collected twice weekly for 24 days after treatment and tested for cysts with a quantitative zinc sulfate flotation technique and for Giardia antigen with an immunoassay. RESULTS: Dogs in phase 1 were all shedding cysts again by day 24. In phase 2, only 1 dog shed cysts after treatment, and shedding was transient (day 17). In phase 3, neither cysts nor antigen was detected in fecal samples from 2 of 4 dogs treated for 3 days and 4 of 5 dogs treated for 5 days. In 18 of 57 (31.6%) fecal samples, cysts were seen, but results of the immunoassay were negative. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that when a combination febantel-praziquantel-pyrantel product is used to treat dogs with giardiasis, bathing and changing the environment after treatment may be more important in preventing recurrence than duration of treatment.     

Evaluation of fenbendazole for treatment of Giardia infection in cats concurrently infected with Cryptosporidium parvum

OBJECTIVE: To determine whether fenbendazole effectively eliminates Giardia organisms from chronically infected cats that have a concurrent Cryptosporidium parvum infection. ANIMALS: 16 clinically normal cats. PROCEDURE: Eight cats with chronic concurrent Giardia and C parvum infections received fenbendazole (50 mg/kg, PO, q 24 h) for 5 days (treatment-group cats). Feces from each cat were collected and processed 3 days weekly for 23 days after treatment. By use of an immunofluorescent assay for detection of Giardia lamblia cysts and C parvum oocysts, organism numbers were counted and scored. Fecal results from treatment-group cats were compared with those of 8 untreated cats with Giardia infection but no C parvum infection (control-group cats). RESULTS: Four of 8 treatment-group cats had consistently negative results for Giardia infection after treatment. These 4 cats had consistently positive results for C parvum oocysts prior to treatment and consistently negative results after treatment. One treatment-group cat had positive results for cysts on all fecal samples, and 3 treatment-group cats had 1 to 3 negative results and then resumed shedding large numbers of cysts; each of these cats had consistently positive results for C parvum oocysts. When compared with control-group cats, treatment-group cats shed less Giardia cysts during week 1 after treatment but not during week 2. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of fenbendazole decreases Giardia cyst shedding to less than detectable numbers in some cats. In our study, persistent C parvum infection may have been associated with failure of fenbendazole to eliminate Giardia infection.     

Observations on natural and experimental infections with Giardia isolated from cats.

The course of infection with Giardia was studied in (a) naturally infected cats and (b) experimentally infected Mongolian gerbils using Giardia cysts isolated from cats. Natural infection was characterized by: (a) a latent period of 11 to 13 days, (b) the pattern of cyst release which was either continuous or intermittent during the acute phase of infection and (c) elimination of the infection in four to five weeks after exposure. Mongolian gerbils were found to be susceptible to infection with Giardia isolated from cats. The course of infection in gerbils was characterized by intermittent cyst release and elimination of the infection in about three weeks. The pattern of cyst release in gerbils infected with Giardia isolated from cats was similar to the previously reported pattern of cyst release in gerbils infected with Giardia isolated from humans. The possible role of pets in the zoonotic transmission of giardiasis is discussed.     

Impact of Giardia vaccination on asymptomatic Giardia infections in dogs at a research facility

Feces were collected from 107 asymptomatic dogs at a research facility in Guelph, Ontario. The prevalence of Giardia infection was 11% (12/107). To assess the effectiveness of Giardia vaccination for treatment of Giardia carriage, 9 additional asymptomatic Giardia antigen-positive dogs were brought into the facility. The Giardia antigen-positive dogs were then randomly allocated to receive either vaccine (n = 10) or a saline placebo (n = 10). Feces were then monitored monthly for 6 mo for Giardia antigen and Giardia cysts. At weeks 4, 8, 12, and 16 following vaccination, there were more Giardia-positive dogs in the vaccinated group (10/10, 9/10, 9/10, 8/10, respectively) compared with the controls (7/10, 7/10, 8/10, 4/10, respectively). At week 20, an equal number of dogs (5/10) were Giardia positive, and at week 24, fewer dogs were positive in the vaccinated group than in the control group (2/10 versus 5/10, respectively). However, there was no significant difference between the 2 groups. Vaccination was, therefore, not an effective treatment for asymptomatic canine Giardia infections in this setting.     

Feline giardiasis: observations on natural and induced infections

The excretion of Giardia sp cysts in the feces of naturally and artificially infected cats fluctuated sporadically, and cysts were undetectable several times during 7 weeks of observation. The mean prepatent period for Giardia infection in 7 cats was 9.6 days (range, 5 to 16 days). The amount of the cyst inoculum did not appear to affect the length of the prepatent period. Six of 11 cats had clinical signs consistent with those of giardiasis. Clinical signs and cyst excretion were eliminated after treatment with metronidazole or furazolidone. Moderate oral or parenteral doses of corticosteroids produced little, if any, alteration in the infection. Postmortem examination of 1 inoculated cat revealed Giardia trophozoites in the jejunum and upper portion of the ileum but not in the duodenum, lower portion of the ileum, cecum, or colon. Giardia cysts isolated from cat feces produced infection in Mongolian gerbils but not in C57BL/6J mice.     

Prevalence and infection pattern of naturally acquired giardiasis and cryptosporidiosis in range beef calves and their dams

The prevalence and infection pattern of naturally acquired giardiasis and cryptosporidiosis in 20 ranch raised beef calves and their dams from birth to weaning was determined. Rectal fecal samples were collected from calves at 3 days of age and weekly thereafter; cows' fecal samples were collected at the time of calving, 1 week later and four times during the summer grazing period. Blood samples were collected from the calves at 3 days of age to determine IgG(1) concentrations. Giardia lamblia cysts were shed by all 20 calves (100%) at some date during the duration of the study. However, only one calf (5%) shed Cryptosporidium parvum on two sample dates during the trial. Giardia cysts were first detected at 3.9+/-1.37 weeks of age with a range of 2-7 weeks of age. The geometric mean number of Giardia cysts in the calf feces increased from none at 1 week of age to a maximum of 2230 cysts/g of feces at 5 weeks of age and then decreased to 2 cysts/g at 25-27 weeks of age. Infection rate of calves shedding Giardia cysts peaked at 85% at 5 weeks of age and then decreased to 21% at 25-27 weeks of age. Giardia cysts, shed by calves peaked 1 week after initial shedding and decreased (P<0.05) for the remainder of the trial with the exception of week 3. There was a lower (P<0.05) percentage of calves shedding Giardia cysts weeks 3-10 and 15-25 compared to when shedding was first detected. All calves had complete or partial transfer of passive immunity as measured by IgG(1) levels. The rate of infection (15%) and the geometric mean number of Giardia cysts in the cows' feces (38.49 cysts/g) numerically increased at 1 week post-calving compared to levels at calving. The rate of infection (40%) numerically increased and the geometric mean number of Cryptosporidium andersoni oocysts in the cow feces (37.48 oocysts/g) increased (P<0.05) at 1 week post-calving and decreased to 0 at 13-16 weeks post-calving. This study is the first to document the cumulative prevalence and infection patterns of Giardia and Cryptosporidium in beef cattle under ranch conditions.     

Effect of vaccination against feline immunodeficiency virus on results of serologic testing in cats

OBJECTIVE: To determine the effect of vaccination against FIV on results of serologic assays for FIV infection. DESIGN: Prospective clinical trial. ANIMALS: 26 specific-pathogen-free cats, 102 laboratory-reared cats (42 unvaccinated and uninfected, 41 vaccinated and uninfected, and 19 infected with FIV), and 22 client-owned cats infected with FIV. PROCEDURE: To determine the onset and duration of anti-FIV antibody production in cats following vaccination with a whole-virus vaccine, serum was obtained from the 26 specific-pathogen-free cats prior to vaccination and weekly for 10 weeks, then monthly for 52 weeks, after vaccination; serum was tested for anti-FIV antibodies with lateral flow and microwell plate ELISAs. To determine the diagnostic performance of serologic assays for FIV infection, plasma from uninfected, unvaccinated cats; uninfected, vaccinated cats; and FIV-infected cats was tested for FIV antibodies with the 2 ELISAs, a western blot assay, and an immunofluorescence antibody assay and for FIV antigen with an ELISA. RESULTS: Anti-FIV antibodies were detected in all 26 vaccinated cats 1 year after vaccination. Sensitivity of the antibody assays for FIV infection was high (98% to 100%). Specificity was high in unvaccinated cats (90% to 100%) but poor in vaccinated cats (0% to 54%). None of the vaccinated or infected cats had detectable FIV antigen in plasma. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that vaccination against FIV causes false-positive results for at least 1 year with currently available serologic assays for FIV infection. Negative FIV antibody assay results are highly reliable for detection of uninfected cats, but positive results should be interpreted with caution.     

The efficacy of a Giardia lamblia vaccine in kittens.

Twenty kittens were vaccinated with a Giardia lamblia vaccine prepared on a commercial scale on day 0 and boosted on day 21 (group 1); while 10 kittens received only saline (group 2). These kittens were challenged on day 35 with 10(6) Giardia lamblia trophozoites by a surgical intraduodenal injection. Three control kittens were not vaccinated and not challenged (group 3). Following challenge, Giardia vaccinated kittens had significantly fewer days in which abnormal stools were observed and reduced food intake occurred compared to saline injected animals. The rate of weight gain between group 1 and group 2 animals was not different in the prechallenge period (day 0 to day 35), but vaccinated animals had a significantly higher weight gain in the postchallenge period (P < 0.05). On day 56, all vaccinated animals were not passing cysts in their feces, while 40% of saline injected kittens had Giardia cysts in their feces. In vaccinated kittens, cysts were never demonstrated in 45% of the animals, while cysts were detected in 90% of the saline injected kittens. Viability of the cysts in vaccinated kittens was 38% while the cysts viability in saline injected kittens was 99%. On postmortem examination, trophozoites could be detected in 5% of vaccinated kittens and 60% of saline injected kittens. Vaccination produced an elevated Giardia specific serum IgG and IgA response prior to challenge and throughout the postinfection period. The Giardia infection in the saline injected group did not induce an elevated specific serum response. Giardia vaccination of kittens provides protection in kittens from an experimental challenge by reducing or eliminating intestinal trophozoites and fecal cyst excretion.     

Long-term immunity in cats vaccinated with an inactivated trivalent vaccine.

OBJECTIVE: To evaluate duration of immunity in cats vaccinated with an inactivated vaccine of feline panleukopenia virus (FPV), feline herpesvirus (FHV), and feline calicivirus (FCV). ANIMALS: 17 cats. PROCEDURE: Immunity of 9 vaccinated and 8 unvaccinated cats (of an original 15 vaccinated and 17 unvaccinated cats) was challenged 7.5 years after vaccination. Specific-pathogen-free (SPF) cats were vaccinated at 8 and 12 weeks old and housed in isolation facilities. Offspring of vaccinated cats served as unvaccinated contact control cats. Virus neutralization tests were used to determine antibody titers yearly. Clinical responses were recorded, and titers were determined weekly after viral challenge. RESULTS: Control cats remained free of antibodies against FPV, FHV, and FCV and did not have infection before viral challenge. Vaccinated cats had high FPV titers throughout the study and solid protection against virulent FPV 7.5 years after vaccination. Vaccinated cats were seropositive against FHV and FCV for 3 to 4 years after vaccination, with gradually declining titers. Vaccinated cats were protected partially against viral challenge with virulent FHV. Relative efficacy of the vaccine, on the basis of reduction of clinical signs of disease, was 52%. Results were similar after FCV challenge, with relative efficacy of 63%. Vaccination did not prevent local mild infection or shedding of FHV or FCV. CONCLUSIONS: Duration of immunity after vaccination with an inactivated, adjuvanted vaccine was > 7 years. Protection against FPV was better than for FHV and FCV. CLINICAL IMPLICATIONS: Persistence of antibody titers against all 3 viruses for > 3 years supports recommendations that cats may be revaccinated against FPV-FHV-FCV at 3-year intervals.     

Accuracy of polymerase chain reaction assays for diagnosis of feline immunodeficiency virus infection in cats

OBJECTIVE: To determine the sensitivity, specificity, and overall diagnostic accuracy of polymerase chain reaction (PCR) assays offered by commercial diagnostic laboratories for diagnosis of FIV infection in cats. DESIGN: Prospective clinical trial. ANIMALS: 124 cats. PROCEDURE: Blood was collected from cats that were neither infected with nor vaccinated against FIV, uninfected cats that were vaccinated with a licensed FIV vaccine, and cats experimentally and naturally infected with FIV representing subtypes A, B, and C. Coded blood samples were submitted to 3 laboratories in the United States and Canada offering PCR assays for diagnosis of FIV infection to veterinary practitioners. All laboratories tested fresh blood samples, and 1 laboratory also tested samples submitted as dried blood smears. The FIV infection status in all cats was confirmed by virus isolation. Sensitivity, specificity, and correct results were calculated for each PCR assay. RESULTS: Sensitivity ranged from 41% to 93%. Specificity ranged from 81% to 100% in unvaccinated cats and 44% to 95% in cats vaccinated against FIV. Correct results were obtained in 58% to 90% of 124 cats tested. All tests misidentified both uninfected and infected cats. False-positive results by all laboratories were higher in cats vaccinated against FIV than in unvaccinated cats, suggesting that vaccination interferes with the performance or interpretation of PCR assays used for diagnosis of FIV infection. CONCLUSIONS AND CLINICAL RELEVANCE: PCR assays used for diagnosis of FIV infection presently marketed to veterinary practitioners in North America vary significantly in diagnostic accuracy and did not resolve the diagnostic dilemma resulting from vaccination of cats against FIV.     

Intranasal vaccination against upper respiratory tract disease (U.R.D.) in the cat—II. Results of field studies under enzootic conditions in The Netherlands with a combined vaccine containing live attenuated calici- and herpesvirus

A live vaccine containing attenuated calici- and herpesviruses was tested in field studies in the Netherlands.This vaccine is administered intranasally. Cats may show local transient reactions in the week following vaccination. The experiments were conducted in three types of infected premises: boarding catteries, homes for stray cats and breeding colonies. In the boarding catteries the vaccine was instilled intranasally at least one week before admission. If this was impossible—like it is in homes for stray cats—the animals were vaccinated at the day of admission and then quarantined for at least 24 hr.In the four boarding catteries 290 cats were vaccinated. Local reations were observed in 25 animals (less than 9%). Five cats (less than 2%) showed clinical symptoms of the disease in spite of vaccination. However these cases were all in the same cattery which also housed stray cats.In three homes for stray cats 257 animals were vaccinated. The percentage of local reactions was much higher (49%) due to suppressed infections and secondary bacterial invaders. Clinical disease was seen in 13 cats (5%). However eight of these cats were in one cattery where some of the requirements of the experiment—c.q. quarantine—could not be met.Prevention of the disease in infected breeding colonies was difficult to achieve because infected parent animals are known to shed virulent virus during rehousing and parturition.The following vaccination program was very successful: parent animals are vaccinated intranasally prior to mating and the pregnant queens again on the day of parturition. The kittens are then vaccinated intranasally at an age of 8–10 days old. With this program the percentage of healthy kittens that could be sold was as high as 98%. This compares to 66% in a previous vaccination program where the queens were given an intramuscular vaccine and the kittens received either several intramuscular vaccinations or one intranasal vaccination on the age of six days.The CH vaccine is available on the Dutch market for one year. The results obtained by veterinary practitioners confirm the good results obtained in the field studies.     

Bovine genital campylobacteriosis (vibriosis): vaccination of experimentally infected bulls

The therapeutic efficacy of a Campylobacter fetus subsp venerealis bacterin was determined in experimentally infected bulls. Ten of twelve 5-year-old Angus bulls became infected after being infused intrapreputially with C fetus subsp venerealis. Of the 10 bulls, 6 were vaccinated with 5 ml of C fetus subsp venerealis vaccine on 2 occasions 4 weeks apart. Preputial washings of the vaccinated bulls were culturally negative by the 8th week after primary vaccination. None of the 18 heifers exposed to the vaccinated bulls became infected. The 4 infected, nonvaccinated bulls remained culturally positive to C fetus (P less than 0.002), and each bull infected at least 1 heifer (P less than 0.001). Two noninfected, nonvaccinated bulls remained culturally negative and did not infect any heifer. The 4 infected, nonvaccinated bulls were then vaccinated. Two bulls remained infected 9 weeks after primary vaccination, as determined by the virgin heifer test and cultural examination of preputial washings. Serologic data from 7 sampling periods were different (P less than 0.001) for vaccinated vs nonvaccinated bulls at 4 (against K antigen) or 6 (against O antigen) weeks after primary vaccination. Vaccination was effective in eliminating the infection in most of the infected bulls, but cannot be recommended as the sole measure of control in infected herds.     

Evaluation of vaccination with a commercial subunit vaccine on shedding of Salmonella enterica in subclinically infected dairy cows

OBJECTIVE: To estimate the efficacy of a commercially available Salmonella enterica subunit vaccine on the subclinical shedding of S enterica in dairy cattle. DESIGN: Randomized, controlled trial. ANIMALS: 175 mature cows on 2 dairy farms with a history of S enterica infection. PROCEDURES: 25% of the mature cows from each herd were systematically randomized to receive an S enterica subunit vaccine following label guidelines. The remaining 75% of cows in each herd served as nonvaccinated controls. Fecal samples were collected from all cows at the time of initial vaccination (day 0), booster vaccination (day 14), 2 weeks following the booster vaccination (day 28), and 10 weeks following the start of the trial (day 70). All samples were processed on the day of collection and cultured for S enterica. RESULTS: 651 fecal samples were obtained over the entire study period. Salmonella enterica was recovered from 46 (7.1%) of the samples. Shedding of S enterica was similar for vaccinated and nonvaccinated control cows on each of the collection dates. CONCLUSIONS AND CLINICAL RELEVANCE: The study revealed no evidence that extralabel vaccination with a commercial subunit S enterica vaccine reduced shedding of S enterica in subclinically infected dairy cows in these herds.     

Giardiasis in a cattery

Giardia sp infection was believed responsible for chronic, intermittent diarrhea in a group of 14 Persian cats. Seven of the cats were shedding Giardia sp cysts, and 6 of these cats had diarrhea at the time of fecal examination. Conversely, only 1 of 6 clinically normal cats in the group was shedding Giardia sp cysts. Cysts were not detected in feces of 2 cats with diarrhea. Cats less than or equal to 3 years old were more likely to be found shedding cysts. The parasite apparently was eradicated from the cattery by a combination of cage disinfection (1% sodium hypochlorite solution) and oral furazolidone treatment (4 mg/kg of body weight, BID for 5 consecutive days). During treatment, clinical signs resolved, and all cats remained clinically normal 2 months after treatment.     

Efficacy and safety of a feline immunodeficiency virus vaccine

Fel-O-Vax FIV is an inactivated virus vaccine designed as an aid in the prevention of infection of cats, 8 weeks or older, by feline immunodeficiency virus (FIV). It contains two genetically distinct FIV strains. The efficacy of this vaccine was demonstrated in a vaccination-challenge study designed to meet various regulatory requirements for registering the vaccine. Eight-week-old kittens were vaccinated with an immunogenicity vaccine which contained minimal release levels of FIV antigens formulated with a proprietary adjuvant system. Twelve months later, all vaccinates and controls were challenged with a heterologous FIV strain. Following the vigorous challenge exposure, cats were monitored for FIV viremia. It was found that 16% of the vaccinated cats developed viremia while 90% of the controls became persistently infected with FIV, which demonstrated that the vaccine was efficacious and the protective immunity lasted for at least 12 months. The safety of the vaccine was demonstrated by a field safety trial in which only 22 mild reactions of short duration were observed following administering 2051 doses of two pre-licensing serials of Fel-O-Vax FIV to cats of various breeds, ages and vaccination histories. Thus, Fel-O-Vax FIV is safe and efficacious for the prevention of FIV infection in cats.     

Effects of repeat fenbendazole treatment in dairy calves with giardiosis on cyst excretion, clinical signs and production

In this 90-day study, 60 male Holstein dairy calves were experimentally infected with Giardia duodenalis. Calves were randomly blocked by weight into treatment (N=30) and placebo (N=30) groups. Beginning on study Day 0, calves in the treatment group were administered an oral dose of 5mg/kg of fenbendazole once daily for three consecutive days. Calves in the placebo group received a daily oral treatment of 5 ml of saline for 3 days. These treatments were repeated on Days 30 and 60 of the study. Fecal samples were collected from calves once per week and examined for the presence of Giardia cysts. Calves were monitored daily for clinical signs of intestinal disease and all episodes of diarrhea recorded. Calves were weighed once per week and total feed intake, on a dry matter basis, was calculated daily. Following each treatment, the number of calves shedding Giardia cysts in the fenbendazole group was reduced (p<0.001) compared to the saline group. Also, calves in the fenbendazole group had fewer cysts (p<0.05) detected in their feces following treatment compared with calves that received saline. Within 2 weeks post treatment, the number of infected animals and fecal Giardia cysts returned to placebo levels. This pattern of reinfection was consistent after every treatment period. Calves receiving fenbendazole had fewer total days with diarrhea (p<0.01) and the average number of days each calf had diarrhea was reduced (p<0.05), compared to the placebo group. There were no differences in mean body weight, average daily gain, or feed intake between the treatment or placebo groups. This study demonstrates that fenbendazole is an effective treatment for giardiosis, resulting in a clinical benefit and reducing the number of infective cysts shed by calves. However, this treatment regime had no impact on production parameters and reinfection occurred rapidly in these calves.     

Vaccination of cats experimentally infected with feline immunodeficiency virus, using a recombinant feline leukemia virus vaccine.

A group of 15 cats experimentally infected with a Swiss isolate of feline immunodeficiency virus (FIV) and a group of 15 FIV-negative control cats were inoculated with an FeLV vaccine containing recombinant FeLV-envelope. High ELISA antibody titer developed after vaccination in FIV-positive and FIV-negative cats. Vaccinated and nonvaccinated controls were later challenge exposed by intraperitoneal administration of virulent FeLV subtype A (Glasgow). Although 12 of 12 nonvaccinated controls became infected with FeLV (10 persistently, 2 transiently), only 1 of 18 vaccinated (9 FIV positive, 9 FIV negative) cats had persistent and 2 of 18 had transient viremia. From these data and other observations, 2 conclusions were drawn: In the early phase of FIV infection, the immune system is not depressed appreciably, and therefore, cats may be successfully immunized; a recombinant FeLV vaccine was efficacious in protecting cats against intraperitoneal challenge exposure with FeLV.     

Treatment of feline giardiasis with metronidazole

Seven cats from a single household with 17 cats were shedding cysts of Giardia species as detected by a modified zinc sulfate concentration technique. All the cats were housed individually in Horsfal isolation units for the duration of the evaluation, treatment, and follow-up monitoring. Each of the infected cats was treated with metronidazole at a dose of 22 mg per kg of body weight, twice a day, for 5 days. Post-treatment examination of four or five stool samples from each cat during the following 17 days did not reveal the presence of any giardial cysts in the treated cats. After treatment, the diarrhea either ceased or was markedly diminished. Therefore, metronidazole appears to be an effective form of therapy for feline giardiasis.