ANTIBIOTICS are commonly prescribed in cats with the intention of helping the host eliminate infectious organisms. However, antibiotics must be chosen and prescribed responsibly due to the increasing prevalence of multidrug-resistant bacterial infections in companion animals and concern regarding overuse and misuse of antibiotics.
Although the choice of antibiotic should ideally be based on culture and sensitivity testing, this is often impractical in clinical situations and veterinary surgeons will often find themselves prescribing antibiotics empirically based on the organisms most likely to be at the site of infection and the properties of the antibiotic in terms of the target tissue.
The use of cytology can also be considered as this can be used to confirm the presence of bacteria and aid preliminary identification of the infecting organism. However, the value of culture and sensitivity testing should not be forgotten, especially in cases where initial therapy has failed.
Empirical therapy with broadspectrum antibiotics should be limited to serious infections or those that are not sensitive to narrow-spectrum antibiotics.
The choice of antibiotics in cats is also importantly dependent on compliance; sometimes cats can be difficult to medicate and good owner compliance is needed to ensure the prescribed antibiotic is given appropriately, at the correct dosing interval and for the intended duration.
Factors that may be important for the veterinary surgeon to consider are any previous experience the owner has in medicating their cat, the availability of the owner to administer medications if dosing is required more than every 12 hours, the normal diet that the cat is fed on if dosing in food is being considered, and whether concurrent medications are being prescribed.
It is important to discuss with the owner how to effectively medicate cats as well as the importance of adhering to the dosing frequency and completion of the course; compliance is likely to be greater if owners understand the importance of the antibiotic treatment course being prescribed. They will often appreciate the knowledge that effective antibiotic administration will maximise the efficacy of the course and minimise relapses, thus reducing the risk of disease recurrence and further antibiotic treatment costs.
If tablets or capsules are being prescribed, owners will often benefit from seeing a demonstration of effective tableting in the consultation room, or the use of pill givers that may aid some owners.
Nurses can be very helpful in instructing clients regarding medicating cats and ensuring owners have the information required to help them effectively medicate their cats. Owners may be more likely to admit to difficulties in medicating their cat to nurses rather than veterinary surgeons.
If the cat is being given more than one oral treatment, it may be possible to combine them within a gelatine capsule, available from veterinary wholesalers, to reduce the number of oral pillings required.
Tablets and capsules may lodge in the oesophagus of cats following pilling; at worst this can result in severe oesophagitis and stricture formation but even if non-irritant, discomfort will be felt by the cat when incomplete swallowing of a tablet or capsule occurs, and this can affect future compliance.
Thus tablet or capsule administration should always be followed by food (if appropriate) or water to encourage complete swallowing; applying a small amount of butter to the nose to encourage the cat to lick and swallow can be very effective.
Pill pockets or soft treats can also be tried in which to hide tablets for oral medications, and some antibiotics can be crushed and given in food or water, although the manufacturer should be contacted to ensure this does not affect efficacy.
Generally, cats are less likely than dogs to take medications hidden in food, although formulations designed to be given with food, particularly liquids and pastes, are often well-tolerated. Owners should be encouraged to get in touch with the practice if any compliance difficulties occur.
Antibiotics can be divided into time-dependent (e.g. penicillins, cephalosporins) and concentrationdependent (e.g. fluoroquinolones, metronidazole) agents according to the method of bacterial killing they use.
Time-dependent antibiotics must be maintained above the minimum inhibitory concentration (MIC) throughout the dosing interval and so it is extremely important to give the antibiotics at the precise dosing intervals stated, e.g. every eight hours compared to three times daily, as the latter may result in owners not understanding that the spacing of dosing is very important.
Concentration-dependent antibiotics have a killing action that is dependent on peak antibiotic concentration achieved, and so they are not as dependent on a strict time interval.
Fluoroquinolones are bactericidal concentration-dependent antibiotics that are usually reserved for use in infections that have confirmed susceptibility to fluoroquinolones or which are deemed to be serious or difficult to treat.
Fluoroquinolones are especially efficacious for Gram-negative aerobic infections, but also show activity against some Gram-positive aerobes. Although they generally show poor activity against anaerobes, pradofloxacin (Veraflox) is active against anaerobes, thus offering broad spectrum activity in cases requiring this.
Once a decision to use a fluoroquinolone has been made, and considerations are given to owner compliance, the availability of pradofloxacin as a palatable oral suspension that requires only oncedaily dosing makes this an attractive formulation for cats.
In the Feline Centre, Langford Veterinary Services, University of Bristol, we have been using pradofloxacin with success in cases for which the need for a fluoroquinolone has been confirmed. Owner compliance has been particularly good as the formulation is easy to administer.
The length of the treatment course will depend upon the type of infection present. However, in our experience with Veraflox, owner compliance has been rewarding for the full duration of treatment, leading to a favourable outcome and eradication of infection in the majority of cases.
