Lower respiratory tract infections in cats: 21 cases (1995-2000)

Twenty-one lower respiratory tract infections diagnosed in cats at University of Sydney Veterinary Centre between 1995 and 2000 were identified retrospectively. Patient records were analysed to determine historical, clinical, clinicopathologic and radiographic features of lower respiratory tract infections. Response to therapy was also assessed. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Mycobacterium thermoresistible, Cryptococcus neoformans, Toxoplasma gondii, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study provides a detailed retrospective analysis of infectious lower respiratory tract disease in this population of cats.     

Vedaprofen therapy in cats with upper respiratory tract infection or following ovariohysterectomy

OBJECTIVES: The antipyretic and analgesic efficacy of vedaprofen (at a dose of 0.5 mg/kg) was evaluated after repeated once-daily administration (for three or five days) to 80 cats with upper respiratory tract disease or 302 cats undergoing ovariohysterectomy. METHODS: Both clinical trials were randomised, double blinded and placebo controlled. RESULTS: In the upper respiratory tract disease trial, vedaprofen produced a significant reduction in rectal temperature when compared with cats administered antimicrobial treatment only. This antipyretic activity lasted at least four hours after administration on the first day of treatment (day 0) and at least eight hours on day 1 and day 2. Significantly more cats in the treatment group were classified as having returned to normal on day 5, day 6 and day 7 compared with the placebo group. In the ovariohysterectomy trial, scores for behaviour (on day 1, day 2 and day 3) and appetite (on day 1 and day 2) were significantly better in the vedaprofen group than in the placebo-treated cats. CLINICAL SIGNIFICANCE: Vedaprofen produced a clinically relevant reduction in body temperature and a more rapid return to normality in cats with upper respiratory tract disease. Vedaprofen treatment also resulted in more rapid recovery, presumably through the relief of pain and inflammation, in cats that had undergone soft tissue surgery.     

Bacteriological and virological status in upper respiratory tract infections of cats (cat common cold complex)

Between October 2002 and January 2005,460 bacteriological samples from cats with an acute upper respiratory tract infection were analysed in clinical field studies in two accredited laboratories in Germany. Oropharyngeal swabs were taken from these cats and sent to the laboratories for routine diagnostics. In the swab samples of 460 cats 382 bacteria strains were isolated.The following bacteria were isolated most frequently: Pasteurella spp. (32.5 %), Staphylococcus spp. (18.5 %), Escherichia coli (17.0 %), Streptococcus spp. (9.1 %), Pseudomonas spp. (6.9 %) and Klebsiella spp. (3.0 %). Bordetella bronchiseptica was found in 0.4 % of the animals To evaluate possible regional and time influences, the animals were split into three populations: 1: Germany, laboratory A; 2: Germany, laboratory B; 3: France and Belgium, laboratory B. In population 1 an 2 Pasteurella spp. were found most frequently with 42.2 % and 36.5 %, respectively.The second most frequently isolated bacterial species were Staphylococcus spp. with 14.1 % and 21.4 % and E. coli with 13.6 % and 17.5 % respectively. In population 3 Staphylococcus spp., E. coli (20 % each) and Pasteurella spp. (18.5 %) were isolated at almost the same frequency. Virological parameter were additionally analysed in 328 cats (population 2 and 3). Serum samples were analysed for antibodies specific for Feline Calicivirus (FCV) and Feline Immunodeficiency Virus (FIV) and for Feline Leukaemia Virus (FeLV) antigen. Oropharyngeal swabs were analysed for Feline Herpesvirus (FHV) by using PCR. Calicivirus-specific antibodies were found in 99.6 % of the cats of population 2 and in 100 % of the animals in population 3. Herpesvirus was detected in 15.3 % and 23.3 % of the cats, respectively. FeLV-Antigen was found in 0.4 % of the animals in population 2 and in 10.1 % of the cats in population 3, while FIV-antibodies were identified in 8.7 % of the animals of population 2 and in 6.1 % of the cats of population 3. In total FHV was found in 19.3 % and FCV-specific antibodies in 99.7 % of the animals. 5.3 % of the cats carried FeLV-Antigen, and 7.4 % FIV-specific antibodies. The results of the bacteriological analysis as well as the results of the virological examination confirm previously published data. In this study Pasteurella spp. were most frequently isolated (32.5 %).     

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 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.     

Bordetella and Mycoplasma respiratory infections in dogs and cats.

The consequences of B. bronchiseptica and mycoplasma infections in dogs and cats vary greatly. Only careful clinical judgment can dictate when to institute antimicrobial and other supportive treatments. Approaches to controlling diseases caused by these organisms should be tailored to meet individual needs. Management strategies that reduce natural exposure levels in the animal's environment and maintain active immunity to contagious components of disease have the highest likelihood of success.     

Viral infections of the respiratory tract of calves: Local immunity

Local immunity is the first defence mechanism against viral respiratory infections in young calves. The great variety of different viruses which may infect the very young animal makes it necessary to develop effective local defences early in life. The best approach appears to be to increase the subjects' defences by using immunoadjuvants and interferon inducers. With this end in view we should increase our knowledge of the immune system of the calf respiratory tract, particularly with respect to specific immunoglobulins, and cells which mediate the immune response.

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Kurzfassung Die örtliche Immunität ist der erste Abwehrmechanismus gegen virale Erkrankungen der Atemwege beim jungen Kalb. Da sich diese sehr jungen Tiere mit den unterschiedlichsten Viren infizieren können, ist ein frühzeitiger Aufbau einer wirksamen örtlichen Abwehr unerlässlich; dieses Problem liesse sich vielleicht durch eine Steigerung der Abwehrkräfte bei den Tieren mit Immunitatsadjuvanten und Induktoren von Interferonbildung bewältigen. Die bisher vorliegenden Angaben über das Immunsystem der Atemwege beim Kalb (spezifische Immunglobuline, Immunzellen) müssen zu diesem Zweck noch vertieft werden.

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Resume L'immunité locale est le premier mécanisme de défense contre les affections réspiratoires virales du jeune veau. La grande diversité des virus pouvant infecter ces sujets très jeunes rend indispensable l'établissement précoce de défenses locales éfficaces; l'augmentation des défenses des sujets par l'emploi d'adjuvants de l'immunite et d'inducteurs d'interféron semble être le moyen d'aborder ce problème. Les données que nous possédons sur le système immunitaire de l'appareil réspiratoire du veau (immunoglobulines specifiques, cellules effectrices de l'immunité) doivent, dans ce but, être approfondies.

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Riassunto L'immunita locale e il primo meccanismo di difesa del giovane vitello contro le affezioni virali delle vie respiratorie. La grande diversità dei virus in grado di infettare soggetti molto giovani rende necessaria l'instaurazione precoce di difese locali efficaci; la soluzione migliore dovrebbe consistere nel potenziamento delle difese dei soggetti mediante adiuvanti dell'immunità e induttori di interferon. A tal fine e necessario approfondire i dati in nostro possesso sul sistema immunitario dell'apparato respiratorio del vitello (Immunoglobuline specifiche, immunociti).

     

Cystocentesis is essential for reliable diagnosis of urinary tract infections in cats

Urine samples were taken from 79 cats with clinical signs of acute feline lower urinary tract disease (FLUTD) by means of cystocenthesis, catheterization, or at voiding and were cultured. No bacteria were cultured from 79% of the samples taken by cystocenthesis, 55% of the samples obtained by catheterization, and 17% of the samples obtained at voiding. Samples obtained by cystocenthesis most often yielded pure cultures, whereas the voided samples were often contaminated, yielding mixed cultures. Therefore, it is difficult to interpret culture results for voided or catheterized urine samples, which may lead to overdiagnosis of urinary tract infections. E. coli was the most prevalent bacterial species. Numbers of bacteria were low (10(2) to 10(3)/ml) in three out of eight culture-positive samples taken by cystocenthesis, indicating that the number of bacteria present in the bladder of cats with urinary tract infections may be low. This may lead to underdiagnosis of urinary tract infections when interpreting culture results for voided and catheterized samples, because bacterial counts lower than 10(3) colony-forming units/ml of urine are generally considered not clinically relevant. In conclusion, cystocenthesis is the preferred method of sampling for the evaluation of cats with suspected urinary tract infection.     

Immune responses to mycoplasma infections of the respiratory tract

Mycoplasmas are capable of causing respiratory disease in a number of species of animals. The pathogenicity of the mycoplasma species ranges from those that cause major disease outbreaks and economic loss to what might be considered the more highly evolved and successful parasites at the other end of the spectrum that survive for long periods in the host without being recognised and evicted. This prolonged colonisation of mucous membranes which is typical of many mycoplasmas is related to certain unique features of the mycoplasma and its interaction with the hosts immune system. An initial step in infection is the attachment of the mycoplasma to the epithelial lining of the respiratory tract. Lack of cell wall confers plasticity and may engender the intimate association of mycoplasma and host cell that has been noted. This in turn may favour persistence of the extracellular parasite. Before the specific immune response is produced avoidance of the non-specific immune mechanisms would clearly aid survival. Both passive (capsules) and active (toxic effects) mechanisms of avoiding phagocytosis have been proposed. Both humoral and cell mediated responses are generated by mycoplasma infections. The serum antibody response follows the usual course IgM, G and A. The indications of cell mediated immunity that have been reported include; delayed type hypersensitivity reactions, lymphocyte transformation responses and inhibition of macrophage migration. The concept that the pathological lesions are in a large part due to host reactivity is well accepted. The lung lesions may contain infiltrating and dividing lymphocytes some of which are producing specific antibody. Evidence for the lung lesion in some animals being partly due to the hosts cell mediated response has also been produced. The local immune response appears to be of greater relevance to immunity to infection than the systemic response, in general the association between local antibody and immunity is much better than for serum antibody. Of particular note is the high contribution of local IgG production, particularly in the lower respiratory tract. Attempts are now being made to use this increased understanding to produce effective killed vaccines that produce immune responses in the lung. Such studies will hopefully lead to the development of 'killed' vaccines that are effective. It can be urged that mycoplasmas would be less pathogenic if they did not produce an inflammatory response and some species have been shown to have an immunosuppressive effect. Such a property could affect the lesion, and hence pathogenicity, and also aid mycoplasma persistence.(ABSTRACT TRUNCATED AT 400 WORDS)