Amoxycillin and clavulanic acid combination in the treatment of experimentally induced bacterial cystitis in cats

Clavulanic acid (CA) competitively inhibits beta-lactamase hydrolysis of penicillins in vitro. Treatment with amoxycillin combined with clavulanic acid (A-CA) was compared with placebo in a blind study in cats with experimental cystitis caused by Escherichia coli demonstrating in vitro resistance to amoxycillin. Bacterial cystitis was induced in 20 cats by bladder infusion of 5 ml of 0.05 per cent alcoholic salicylic acid followed after 24 hours by a brain-heart infusion broth of E coli (10(8) colony forming units ml-1) previously found to be resistant to amoxycillin in vitro (minimum inhibitory concentration over 512 micrograms ml-1). Four days after infection, cats were randomly divided into two groups of 10 and treated with amoxycillin combined with clavulanic acid or placebo for 10 days. When compared to the placebo-treated group, the A-CA treated group showed: reduced quantitative bacterial counts in urine on days 7 (P less than 0.001) and 14 (P less than 0.02); reduced culture positive urine on days 7 (P less than 0.001) and 14 (P less than 0.001); and less severe inflammation on histological examination of the bladder and urethra (P less than 0.01). It was concluded that A-CA was effective in reducing the bacterial count and reducing the histopathological changes in the bladder and urethra in an experimental model of acute bacterial cystitis in cats infected with an E coli demonstrating in vitro resistance to amoxycillin.     

The clinical efficacy of topical and systemic therapy for the treatment of feline ocular chlamydiosis

Twenty-four specific-pathogen-free-derived cats aged four to 11 months were challenged by ocular application of a field isolate of Chlamydia psittaci to evaluate the effect of topical and systemic therapy on the course of disease. The cats were monitored for 35 days post-challenge, with severity of clinical signs being measured using a scoring system, and ocular shedding of the organism monitored by culture of conjunctival swabs. All cats developed active C psittaci infection, and after 7 days the cats were randomly assigned to one of four treatment groups: Group P (placebo) was given twice-daily ophthalmic tear-replacement ointment; group F was given twice-daily topical 1% fusidic acid ophthalmic viscous drops; group C was given twice-daily topical 1% chlortetracycline ophthalmic ointment; and group D was given doxycycline at 10 mg/kg daily per os in addition to twice-daily topical 1% fusidic acid ophthalmic ointment. Within 24 h of commencement of therapy, group D had significantly lower median clinical scores than group P, and with the exception of day 16, this trend was maintained throughout the observation period. Median clinical scores of cats in group F were not appreciably different to those in group P, whereas the median scores of cats in group C generally fell between those of groups P and D. The median duration of C psittaci shedding was 10 and 15 days for groups D and C respectively, but four of the six cats in groups F and P were still shedding organisms at the end of the study (day 35). In this study, systemic therapy with doxycycline proved superior to topical therapy in the treatment of feline chlamydiosis.     

Oral glucosamine and the management of feline idiopathic cystitis

Oral glucosamine was compared to a placebo for the management of cats with feline idiopathic cystitis (FIC) in a randomised, double-blinded, placebo-controlled, study. Forty cats with a history of recurrent cystitis due to FIC were divided into two groups and treated daily per os with either 125 mg N-acetyl glucosamine or a placebo for six months. Owners graded their cats' clinical signs at the beginning and end of the study, and kept daily diaries documenting signs of cystitis using visual analogue scales. Further episodes of cystitis were seen in 26 (65%) of the cats during the study. Affected cats experienced a mean of five recurrences (range 1-19) with each recurrence lasting a mean of four days (range 1-64 days). There were no significant differences between the two groups when considering the owners assessments of the mean health score (P>0.5), the average monthly clinical score (P=0.22) or the average number of days with clinical signs (P=0.28). Two cats suffered from such severe recurrent urethral obstruction that they were euthanased; they were both in the placebo group. Compared to the start of the study the majority of cats in both groups improved significantly (P<0.001) (mean health score of each group at the start was 0.5+/-SD 0.5, compared to glucosamine 4.4+/-0.7 and placebo 3.9+/-1.6 at the end). This is believed to have occurred because the owners of 36 of the 40 cats (90%) started feeding more canned cat food. The urine specific gravity at the start of the trial was significantly higher (mean 1.050+/-SD 1.007) than when reassessed one month later (1.036+/-1.010, P<0.01).     

Pharmacokinetics of enrofloxacin and its efficacy in comparison with doxycycline in the treatment of Chlamydophila felis infection in cats with conjunctivitis

The concentrations of enrofloxacin were measured in the tears, saliva and serum of 14 cats with signs of upper respiratory tract infection and eight with no signs, after daily doses of 5 mg/kg. Enrofloxacin concentrations above the minimum inhibitory concentration of Chlamydophila felis were found in the saliva and tears of the cats with and without signs of upper respiratory tract infection. In a prospective randomised clinical trial, the efficacy of enrofloxacin against C. felis infection in cats with conjunctivitis was compared with the efficacy of doxycycline. Twenty-five cats were randomly assigned to treatment with either enrofloxacin or doxycycline for 14 days; 15 of the cats tested positive for C. felis by an immunofluorescent antibody test on conjunctival swabs. The two treatment groups showed equal improvements in the clinical signs of conjunctivitis and C. felis infection status; in each group three cats were still C. felis antigen-positive after the 14-day course of treatment, indicating a persistent infection. No side effects were observed in the cats treated with enrofloxacin.     

Efficacy of milbemycin oxime against fourth-stage larvae and adults of Ancylostoma tubaeforme in experimentally infected cats

The efficacy of milbemycin oxime against fourth-stage (L4) larvae and adults of Ancylostoma tubaeforme was investigated in a trial involving 24 young domestic shorthair cats. The animals were inoculated with approximately 300 infective stage three (L3) larvae and divided into three groups. After 12 days, eight cats (group 1) were treated with medicated tablets containing 4 mg milbemycin and 10 mg praziquantel to test the efficacy against L4 larvae; eight cats in group 2 were treated with the same tablets after 33 days to test the efficacy against adult worms; and eight cats in group 3 were treated with a placebo tablet. Faecal egg counts were determined periodically in each cat and after 40 or 41 days the number of worms in each animal was determined postmortem. The egg count reduction was determined by comparing the geometric mean numbers of eggs per gram of faeces in the placebo and medicated groups, and the worm reduction by comparing the geometric mean numbers of worms. The egg count reduction was more than 99 per cent in both treated groups, while the number of worms in groups 1 and 2 were reduced by 94.7 per cent and 99.2 per cent, respectively.     

Efficacy of a milbemycin oxime-praziquantel combination product against adult and immature stages of Toxocara cati in cats and kittens after induced infection

Two studies were performed to examine the efficacy of milbemycin oxime against fourth-stage larvae or adults of Toxocara cati. In the study to determine efficacy against fourth-stage larvae, 20 domestic shorthair cats were inoculated with 500 embryonated eggs. Four weeks after inoculation, the animals were allocated to two groups, and cats in one group were treated with medicated tablets containing 4 mg milbemycin oxime and 10mg praziquantel (MILBEMAX) and cats in the other group with placebo tablets. Seven days after treatment the animals were euthanatized and necropsied for worm counting. The number of worms found was significantly (p=0.0002) lower in cats treated with medicated tablets than in cats treated with placebo tablets. The reduction in the number of worms was 96.53%. In the study to determine efficacy against mature adult worms, 13 kittens were inoculated with T. cati embryonated eggs. On day 45 after inoculation and after the infection had been confirmed through faecal examinations for 11 out of the 13 animals, the 11 infected animals were allocated to two groups and treated as in the first study. Seven days after treatment, all animals were euthanatized and necropsied for worm counting. The number of worms found was significantly (p=0.0043) lower in kittens treated with medicated tablets than in kittens treated with placebo tablets. The reduction in the number of worms was 95.90%. No adverse effects were recorded during either study. It is concluded that the milbemycin oxime-praziquantel tablets that were used are efficacious for the control of T. cati infections in cats.     

Use of pentosan polysulphate in cats with idiopathic, non-obstructive lower urinary tract disease: a double-blind, randomised, placebo-controlled trial

Idiopathic feline lower urinary tract disease (FLUTD) is a common clinical entity where different treatments, for example glycosaminoglycans (GAGs) such as pentosan polysulphate (PPS), are advocated. However, few treatments have been investigated by well-controlled clinical trials. This paper compares the use of PPS in FLUTD compared to placebo. Of the 18 cats in the experiment, nine were treated with PPS and nine were treated with placebo with subcutaneous injections of 3mg/kg PPS or placebo day 1, 2, 5 and 10. The study was double-blind, randomised and placebo-controlled. Revaluation was performed after 5 and 10 days, 2 weeks, 2, 6 and 12 months. There were no statistically significant differences concerning clinical signs between groups during treatment or at re-evaluation, except for pretreatment stressful events where PPS-treated cats had experienced significantly more stressful events compared to cats treated with placebo before entering the study. Six cats (33%) showed recurrence of clinical signs during the entire study period, and only one of these cats had more than one recurrent episode. One cat (placebo) was euthanased 7 days after initial treatment because of recurrence of clinical signs. Another cat (placebo) was euthanased due to other reasons after 6 months. At 2 weeks two cats (placebo and PPS) showed clinical signs. At 2 months re-evaluation one cat showed mild clinical signs. At 6 and 12 months all remaining 16 cats were healthy. Idiopathic, non-obstructive FLUTD is a self-limiting disease with good short-term and excellent long-term prognosis without treatment. Whether or not PPS may be beneficial in a subpopulation of cats with continuous or frequently recurring clinical signs may be elucidated in forthcoming double-blind, randomised and placebo-controlled trials including only this subpopulation of cats.     

In vitro antimicrobial susceptibilities of three Porphyromonas spp and in vivo responses in the oral cavity of cats to selected antimicrobial agents

OBJECTIVES: To determine in vitro susceptibility of Porphyromonas gingivalis, P salivosa and P circumdentaria to seven antimicrobial agents by agar dilution and Epsilometer test methods and to assess the effectiveness of these antimicrobial agents in reducing the numbers of each Porphyromonas spp in the oral cavity of 16 domestic cats. DESIGN: A two-part prospective study involving in vitro antimicro-bial studies using Porphyromonas spp obtained from naturally occurring feline infections and in vivo antimicrobial response studies using client-owned cats with naturally occurring periodontal disease. PROCEDURE: Isolates (n = 25) of three feline Porphyromonas spp from the oral cavity and oral-associated disease were tested for their in vitro susceptibility to amoxycillin, amoxycillin-clavulanate, benzylpenicillin, clindamycin, doxycycline, erythromycin and metronidazole, using agar dilution and Epsilometer test methods. Digoxigenin-labelled whole chromosomal DNA probes directed against P gingivalis VPB 3492, P circumdentaria NCTC 12469T and P salivosa VPB 3313 were used to quantify organisms taken from two sample sites at the gingival margins of these cats prior to, and 5 days after, treatment with one of four commonly used antimicrobial products (amoxycillin-clavulanate, clindamycin, doxycycline or spiramycin-metronidazole). The response to treatment was assessed clinically for each cat. RESULTS: All isolates were susceptible in vitro to all seven antimicrobial agents using both methods. The numbers of P gingivalis were not reduced at the gingival sample sites by administration of amoxycillin-clavulanate for 5 days, although this treatment reduced the numbers of P salivosa and P circumdentaria to below detection levels in six of eight and two of three of sample sites, respectively; clinical improvement was not observed in cats treated with amoxycillin-clavulanate. Treatment with clindamycin, doxycycline or spiramycin-metronidazole resulted in clinical improvement and a marked reduction of all Porphyromonas isolates at the sample sites. CONCLUSION: The Epsilometer test is a simple and accurate method for determining the minimum inhibitory concentration for P gingivalis, P salivosa and P circumdentaria. All strains were susceptible in vitro to all the antimicrobial agents tested although clinical improvement of gingival disease was not noted with amoxycillin-clavulanate when given for 5 days at usual doses. This appears to be the first report of the disparity between the in vivo and in vitro susceptibility of oral bacterial strains to amoxycillin-clavulanate in the veterinary dental literature. This also appears to be the first report in which clinical and microbiological responses to commonly used antimicrobial agents for periodontal disease in cats has been documented and quantified. It was shown that treatment with clindamycin, spiramycin-metronidazole or doxycycline not only produced a substantial reduction in the number of Porphyromonas spp (in the majority of cases to below detection levels), but also resulted in substantial clinical improvement. This would indicate that these antimicrobial agents are useful adjunctive therapy to mechanical debridement in domestic cats.     

Efficacy of clavulanate-potentiated amoxycillin in experimental and clinical skin infections

The efficacy of clavulanate-potentiated amoxycillin was compared with amoxycillin alone in experimental staphylococcal infection in dogs and in a controlled trial in clinical cases of skin infection in dogs and cats. The experimental infection was produced by subdermal inoculation with beta-lactamase producing (amoxycillin resistant) staphylococci absorbed in cotton dust. This produced discrete, localised lesions with no systemic involvement. In a cross over study, six animals were randomly allocated to treatment with either amoxycillin alone (10 mg/kg, dosed twice daily) or a formulation of clavulanate-potentiated amoxycillin (12.5 mg/kg, of a 1:4 ratio, dosed twice daily). The lesions of the animals treated with clavulanate-potentiated amoxycillin resolved more quickly than those treated with amoxycillin alone. The difference was significant (P less than 0.05) for both lesion diameter and inflammation score after day 6 of treatment. A trial was carried out in clinical cases of skin disease which were randomly allocated to twice daily treatment with either amoxycillin alone (10 or 20 mg/kg), or with clavulanate-potentiated amoxycillin (12.5 or 25 mg/kg of a 1:4 ratio). The required duration of treatment was shorter (P less than 0.5) for the potentiated amoxycillin treatments, and the success rate (judged by cure or substantial improvement) was higher (P less than 0.05) for this group, especially (P less than 0.01) where amoxycillin resistant organisms were isolated. It was concluded that clavulanate-potentiated amoxycillin was an effective treatment of skin infections both under experimental and clinical conditions.     

Evaluation of the efficacy of oral lufenuron combined with topical enilconazole for the management of dermatophytosis in catteries

The efficacy of oral lufenuron, a chitin synthetase inhibitor, combined with topical enilconazole, was evaluated for the management of Microsporum canis infection in 100 cats housed in two catteries in France. The cats were treated with weekly rinses with enilconazole (0.2 per cent) for four weeks and, in each cattery, one group (A) was also treated with micronised griseofulvin (25 mg/kg administered orally twice a day for five weeks) and a second group (B) was treated with 60 mg/kg lufenuron administered orally once on day 0 and again after 30 days. All the cats were examined individually for cutaneous lesions and mycological cultures were made when the treatment began and after 15, 30, 60 and 90 days. In the first cattery, the cats' clinical scores after 30 and 60 days were significantly lower in group B than in group A. In both catteries and both treatment groups, the mean number of fungal colonies decreased rapidly during the first 15 days of treatment, remained stable for the following 45 days but increased from day 60 to the end of the experiment on day 90.     

Use of enrofloxacin for treatment of large-form Haemobartonella felis in experimentally infected cats

OBJECTIVE: To compare treatment with enrofloxacin and doxycycline with no treatment in cats experimentally infected with Haemobartonella felis. DESIGN: Prospective case-control study. ANIMALS: 16 cats. PROCEDURE: Cats were inoculated with large-form H. felis from a chronically infected donor. Cats were assigned to 1 of 4 treatment groups: doxycycline (5 mg/kg [2.3 mg/lb], p.o., q 12 h), low-dose enrofloxacin (5 mg/kg, p.o., q 24 h), high-dose enrofloxacin (10 mg/kg [4.5 mg/lb], p.o., q 24 h), and an untreated control group. Clinical signs, Hct, blood smears, and a polymerase chain reaction (PCR) assay were used to monitor progression of the infection. RESULTS: All cats were confirmed to be infected with H. felis via blood smear evaluations and PCR assay results. Treatment had no effect on Hct during the intratreatment period, but Hct values were significantly greater in the low-dose enrofloxacin group, compared with the control group, during the posttreatment period. During the intratreatment period, H. felis organism counts per 1,000 RBC in the doxycycline treatment and the high-dose enrofloxacin treatment groups decreased at a significantly faster rate than those in the control group. In the posttreatment period, organism counts in the doxycycline treatment group and the low- and high-dose enrofloxacin groups decreased at significantly faster rates than counts in the control group. There was no significant effect of treatment on the number of positive PCR assay results. Two cats treated with enrofloxacin and 1 cat treated with doxycycline completely cleared the H. fe is organism despite presumed immunosuppression caused by glucocorticoids. CONCLUSIONS AND CLINICAL RELEVANCE: Results support the hypothesis that enrofloxacin has anti-H. felis effects.     

Effect of oral administration of L-lysine on conjunctivitis caused by feline herpesvirus in cats

OBJECTIVE: To determine whether oral administration of L-lysine to cats would lessen the severity of conjunctivitis caused by feline herpesvirus (FHV-1). ANIMALS: 8 healthy young adult cats. PROCEDURE: Cats received oral administration of lysine monohydrochloride (500 mg, q 12 h) or placebo (lactose) beginning 6 hours prior to inoculation of virus. The left conjunctival sac received a 50-microl suspension of FHV-1 grown in cell culture (1.8 X 10(8) tissue culture infective dose50) on day 1. Cats were evaluated and scores given for clinical signs each day for 21 days. Samples for virus isolation were collected from the eye and throat every third day. Plasma lysine and arginine concentrations were measured prior to the study and on days 3, 14, and 22. RESULTS: Cats that received lysine had less severe conjunctivitis than cats that received placebo. Virus isolation results did not differ between the groups. Plasma lysine concentration was significantly higher in cats that received lysine, compared with control cats, whereas plasma arginine concentrations did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of 500 mg of lysine to cats was well tolerated and resulted in less severe manifestations of conjunctivitis caused by FHV-1, compared with cats that received placebo. Oral administration of lysine may be helpful in early treatment for FHV-1 infection by lessening the severity of disease.     

Efficacy of a novel formulation of metaflumizone for the control of fleas (Ctenocephalides felis) on cats

A novel spot-on formulation containing metaflumizone (ProMeris for Cats, Fort Dodge Animal Health, Overland Park, KS) was evaluated in five laboratory studies to determine the duration of residual efficacy in cats against fleas after a single spot treatment. In each study, eight domestic shorthair cats were randomly allocated to each treatment group and individually housed. One group in each study remained non-treated. In one study, an additional group of eight cats was treated with a placebo formulation. Cats were treated topically with metaflumizone formulation to provide a dose of at least 40mg metaflumizone/kg. Cats were infested with 100 cat fleas (Ctenocephalides felis felis) once per week for approximately 8 weeks. Cats were comb counted 48h after treatment and each infestation to determine the number of viable fleas present. There were no significant differences in flea counts between the non-treated control and the placebo-treated control (P>0.05) other than a 26% reduction at week 1, demonstrating that the formulation excipients had no activity. Metaflumizone treatment resulted in significantly lower flea numbers relative to non-treated controls on all post-treatment count days (P<0.05). Metaflumizone provided >90% control of flea infestations up to 7 weeks following a single treatment.     

Randomized controlled trial of the efficacy of short-term amitriptyline administration for treatment of acute,nonobstructive, idiopathic lower urinary tract disease in cats

OBJECTIVE: To determine whether short-term amitriptyline administration would be efficacious in the treatment of acute, nonobstructive, idiopathic lower urinary tract disease in cats. DESIGN: Randomized controlled trial. ANIMALS: 31 untreated male and female cats with acute, nonobstructive, idiopathic lower urinary tract disease. PROCEDURES: Cats were treated with amitriptyline (5 mg/d; n = 16) or a placebo (15) for 7 days and monitored for pollakiuria, hematuria, and adverse events. Cats were reexamined 1 month after treatment, and owners were interviewed by telephone 6, 12, and 24 months after treatment. RESULTS: 2 amitriptyline-treated cats were excluded from analyses because of acquired urinary tract infection. Clinical signs resolved by day 8 in 8 amitriptyline-treated and 10 control cats. There were no apparent differences in likelihood or rate of recovery from pollakiuria or hematuria between groups. Overall, clinical signs recurred significantly faster and more frequently in amitriptyline-treated than control cats. However, after excluding recurrences within 21 days of treatment, risk of recurrence was similar in both groups. Increasing age was significantly associated with increased likelihood and rate of recovery from hematuria and with decreased risk of recurrence of signs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that short-term amitriptyline treatment has no benefit in terms of resolution of pollakiuria and hematuria in cats with idiopathic lower urinary tract disease and may be associated with an increased risk of recurrence.     

Measurements of growth hormone and insulin-like growth factor 1 in cats with diabetes mellitus

Serum concentrations of insulin-like growth factor 1 (IGF-1) and growth hormone were measured in 25 cats with untreated diabetes mellitus (11 of which were used for follow-up measurements, one to three, four to eight, nine to 12 and 13 to 16 weeks after their treatment with insulin began), 14 diabetic cats that had previously been treated with insulin, and seven diabetic cats that also had hypersomatotropism, two of which had not previously been treated with insulin; 18 healthy cats were used as controls. In the untreated diabetic cats the concentration of IGF-1 ranged from 13.0 to 433.0 ng/ml (median 170.5 ng/ml), which was significantly lower than the concentrations in the control cats (196.0 to 791.0 ng/ml, median 452.0 ng/ml). Their IGF-1 concentrations increased significantly when they were treated with insulin and after four to eight weeks were not different from those in the control cats. In the diabetic cats that had previously been treated with insulin the IGF-1 concentrations were 33.0 to 476.0 ng/ml (median 316.0 ng/ml), which was significantly lower than the concentrations in the control cats, but significantly higher than in the untreated diabetic cats. The IGF-1 concentrations in the two previously untreated diabetic cats with hypersomatotropism were low and low-normal but increased markedly after treatment with insulin. In the five previously treated cats with hypersomatotropism the concentration of IGF-1 was above the normal range. The concentrations of growth hormone in the treated and untreated diabetic cats without hypersomatotropisms were not significantly different and there was an overlap in its concentrations in the diabetic cats with and without hypersomatotropism.     

Evaluation of the safety of daily administration of capromorelin in cats

Capromorelin is a ghrelin receptor agonist that is FDA approved for appetite stimulation in dogs. The objective of this study was to evaluate the safety of daily oral administration of capromorelin to cats over a range of doses and for an extended period. Two randomized, controlled studies were conducted: in Study 1, cats (n = 6 per group) received placebo or capromorelin at a dose of 9, 15, 30 or 60 mg/kg once daily for 14 days; and in Study 2, cats received capromorelin at 6 mg/kg (n = 8) or placebo (n = 4) once daily for 91 days. Cats were evaluated using clinical observations and clinical pathology test results for both studies, with the addition of postmortem examination in Study 1 and measurements of growth hormone and insulin‐like growth factor 1 in Study 2. Abnormal clinical observations were limited to emesis, hypersalivation, lethargy/depression, head shaking and lip smacking, which occurred more frequently in the capromorelin‐treated groups than in the placebo group. There were no clinically relevant differences in clinical pathology test results between the capromorelin and placebo groups in either study.     

Efficacy of selamectin against biting lice on dogs and cats

The efficacy of selamectin was evaluated against naturally acquired Trichodectes canis infestations on dogs and against Felicola subrostratus infestations on cats. Twenty dogs and 18 cats were randomly allocated to treatment with either a placebo or selamectin (6 mg/kg), administered topically once only on day 0. The treatment had no adverse effects in either the dogs or the cats. Efficacy was assessed by counting the live lice (adults and nymphs) on each animal by using a coat-parting technique on days -3, 7, 14, 21, 28, 35 and 42 for the dogs, and on days -1, 7, 21, 35 and 42 for the cats. On day 43, the number of live lice on each dog was also assessed by using a whole-body combing technique. Selamectin was 100 per cent effective in killing biting lice on the dogs and cats throughout the period of assessment; the louse counts on the treated dogs and cats were significantly lower than the pretreatment counts (P = 0.0001) and were also significantly lower than on the placebo-treated dogs (P < 0.05) and cats (P = 0.0001). There was a marked reduction in the prevalence of clinical signs associated with ectoparasite infestation in the treated dogs and no clinical signs were observed in any of the treated cats.     

Efficacy of pradofloxacin in cats with feline upper respiratory tract disease due to Chlamydophila felis or Mycoplasma infections

BACKGROUND: Upper respiratory tract disease (URTD) of cats is caused by a number of pathogens, including Chlamydophila felis and Mycoplasma spp. For effective treatment of both infections, doxycycline and enrofloxacin are recommended, but adverse effects limit their use in cats. HYPOTHESIS: That the fluoroquinolone pradofloxacin is effective against C. felis and Mycoplasma infection in cats with URTD or conjunctivitis. ANIMALS: Thirty-nine cats with signs of URTD or conjunctivitis. METHODS: Placebo-controlled, double-blind clinical trial. Cats were randomly entered into 1 of 2 treatment groups: treated PO with either 5 mg/kg pradofloxacin q24h or 5 mg/kg doxycycline q12h for 42 consecutive days. Changes in health status and clinical scores were evaluated. The presence of C. felis and Mycoplasma spp. was determined by quantitative polymerase chain reaction (PCR) and nested PCR of conjunctival swabs, respectively. RESULTS: At the beginning of the study, C. felis and Mycoplasma spp. were detected in 23 and 20 cats, respectively. Cats of both groups responded rapidly with a marked improvement in clinical signs within the 1st week. During treatment with either drug, C. felis DNA copy number declined quickly. Complete elimination of Mycoplasma spp. was achieved in both groups; however, whereas all cats receiving doxycycline eliminated C. felis, 4 cats treated with pradofloxacin remained PCR-positive. CONCLUSION AND CLINICAL IMPORTANCE: This study demonstrates that both pradofloxacin and doxycycline have good efficacy against C. felis and Mycoplasma spp., resulting in a marked improvement of clinical signs. However, C. felis DNA remained in some cats after treatment with pradofloxacin, suggesting that infection might not have been eliminated.     

Efficacy of amoxycillin and azithromycin for the empirical treatment of shelter cats with suspected bacterial upper respiratory infections

Thirty-one cats showing clinical signs of upper respiratory tract disease with a presumed bacterial component based on clinical signs were administered either amoxycillin or azithromycin to determine which drug protocol was optimal for empirical use. A clinical score was determined and nasal and pharyngeal swabs were collected for bacterial culture, virus isolation and polymerase chain reaction prior to the start of therapy. Cats failing to respond to the initial antibiotic were then administered the other drug. There were no differences in clinical scores between the two groups at the start of therapy. Eleven of 31 cats improved after administration of the first antibiotic, 16 cats were switched to the alternate antibiotic, and four cats were removed from the study for additional supportive treatments. Eight of 27 cats failed to respond to either antibiotic. The chi2 test for outcomes revealed no differences in response to therapy for either antimicrobial.     

Efficacy of azithromycin for the treatment of feline chlamydophilosis

The current recommended treatment for feline chlamydophilosis involves daily oral administration of antimicrobials to all cats within an affected group for a prolonged period of time (4-6 weeks). Not surprisingly, owner compliance can be poor resulting in apparent treatment failure. Recent anecdotal evidence, supported by its efficacy in the treatment of Chlamydia trachomatis infection in humans, has suggested that azithromycin may offer an alternative by allowing less frequent dosing for a shorter duration. A clinical trial was designed to evaluate the efficacy of azithromycin for the treatment of chlamydia (Chlamydophila felis) infection in cats. Whilst azithromycin, given at 10-15 mg/kg daily for 3 days and then twice weekly, provided a similar, rapid resolution of clinical signs and negative isolation scores as doxycycline, C felis was re-isolated in four out of the five cats treated. Furthermore, even daily administration of azithromycin to chronically infected cats was ineffective in clearing infection. The azithromycin protocols used here were therefore found to be unsuccessful in eliminating the carriage of this strain of C felis.