Enterococcus is one of the intestinal bacterial infections that is becoming more drug-resistant in humans. Vancomycin used to be the drug of choice for treating it but no longer seems to bring enterococcus under control in humans the way it used to. PubMed has numerous studies which seem to indicate this is also becoming true with respect to animals.
With respect to the issue of blindness in cats taking Baytril, I found the following when doing a search of ENTREZ-PUBMED:
: J
vet Med A Physiol Pathol Clin Med 2001 Feb;48(1):59-63
Investigation of biochemical and haematological side-effects of enrofloxacin in dogs.
Tras B, Maden M, Bas AL, Elmas M, Yazar E, Civelek T.
Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine,
University of Selcuk, Konya, Turkey.
In the present study, effects of enrofloxacin on biochemical, haematological and blood gas parameters were investigated. Changes in laboratory parameters were monitored during the treatment period. Enrofloxacin was administered (5 mg/kg intramuscularly, once daily) to 10 healthy dogs for 14 days. Acidosis and temporary increases in aspartate aminotransferase, indirect bilirubin, sodium, partial pressure of CO2 and mean corpuscular volume levels as well as decreased levels of inorganic phosphorus, ionized
calcium, potassium, partial pressure of O2 and standard bicarbonate were observed. The results of this study suggest that these observed effects of enrofloxacin on blood gas parameters should be taken into consideration in long-term use of the drug.
PMID: 11515313 [PubMed - indexed for MEDLINE]
I also found the following data regarding feline blindness & Baytril:
Veterinary Ophthalmology
Volume 4 Issue 2 Page 99 - June 2001 Enrofloxacin-associated retinal degeneration in
cats Kirk N. Gelatt, Alexandra van der Woerdt, Kerry L. Ketring, Stacy E. Andrew,
Dennis E. Brooks, Daniel J. Biros, Heidi M. Denis and Timothy J. Cutler
OBJECTIVE:
The objective of this study was to evaluate the possible relationship between the administration of parenteral enrofloxacin and the onset of acute retinal degeneration in cats. The animals studied included 17 cats that received systemic enrofloxacin and developed retinal degeneration soon thereafter.
PROCEDURES:
In this retrospective clinical study, cats that received parenteral enrofloxacin and developed acute blindness were identified. Parameters recorded included breed, age, sex, enrofloxacin dosage (daily dose and number of days administered), medical condition for which the antibiotic had been prescribed, ophthalmic signs, examination results, and the visual outcome. Fundus photographs were obtained in seven cats, and electroretinography was performed in five cats. Histopathology was performed on two eyes from one cat (case 1) that received enrofloxacin 5 months previously and developed retinal
degeneration.
RESULTS:
All cats were the domestic shorthair breed; seven were females (one neutered) and ten were males (seven castrated). Ages ranged from 3 to 16 years old (mean ± SD; 8.8 ± 4.6 years). The medical disorders for which enrofloxacin was administered ranged from lymphoma and pancreatitis to otitis and dermatitis, and eight cats had urinary diseases. The daily and total dosage of enrofloxacin and number of days of administration were also highly variable. Presenting clinical signs were most often mydriasis (great dilation of the pupil) and acute blindness. All cats had diffuse retinal degeneration as evidenced by increased tapetal reflectivity and retinal vascular attenuation. Absence of recordable electroretinographic responses suggested diffuse and extensive outer retinal disease. Vision returned in a few cats, but the retinal degeneration persisted or even progressed. Histopathology of two eyes revealed primarily outer retinal degeneration, with diffuse loss of the outer nuclear and photoreceptor layers, and hypertrophy and proliferation of the retinal pigment epithelium.
CONCLUSION:
Parenteral enrofloxacin is potentially retinotoxic in some cats, and may result in acute
and diffuse retinal degeneration. Blindness often results, but some cats may regain vision.
Practitioners should adhere closely to the manufacturer's current enrofloxacin dosage
recommendation (5 mg/kg q 24 h), and continue clinical observations for this drug
toxicity in cats.
Lastly, I found information on Baytril that states:
"Enrofloxacin (Baytril Rx) and tetracycline antibiotics should not be given to growing pets
unless absolutely necessary due to the potential for problems with absorption of the medications into bone and/or teeth, causing defects. Use of antibiotics should be restricted to conditions which are likely to respond to appropriate antibiotic therapy since these are not harmless medications. When they are necessary it is obvious that some risk of use is justified."
Here are some
links for those interested in the issue of side effects regarding Baytril:
In summary, it appears that the blindness problem noted in cats with respect to Baytril is of an idiosyncratic (abnormal susceptibility to an agent/drug that is peculiar to an individual or particular species) in nature and has not been observed in other animal species to date. I myself am not overly concerned about the blindness issue as I had one glider that was on Baytril for approx. 8 weeks with the dose being doubled the last 6 weeks and there were no visual problems noted with that glider. This is not to say it couldn't happen but I don't want people to panic on the issue of Baytril causing blindness in their gliders as the studies done indicate this problem to be idiosyncratic to cats for some reason.
Some
links for those interested:
http://www.fda.gov/cvm/index/safety/baytrilDDL.htm http://www.marvistavet.com/html/body_enrofloxacin.html http://www.baytril.com/index.cfm/page/13 <small>[ 12-12-2002, 05:06 PM: Message edited by: Glideroo ]</small>