Cephalexin, a first-generation bactericidal cephalosporin, is considered to be the first-choice antibiotic in the treatment of superficial pyoderma because it is both extremely effective and very safe (Frank and Kunkle,1993; Guaguere and others 1998).
It is very effective against Gram positive cocci, particularly Staphylococcus pseudointermedius, and is resistant to beta-lactamases (Mason and Keitzmann 1999).<br>
When administered orally, cephalexin is well absorbed, with a 70 to 90 per cent bioavailability and optimal distribution in interstitial extracellular fluids (Papich1984; Mason and Keitzmann 1999).
It is still one of the most important tools available nowadays. The antistaphylococcal activity is no less potent than higher-tier antibiotics, and is appropriate for empirical treatment of uncomplicated canine pyoderma.
First-generation cephalosporins (e.g.cephalexin) are usually administered to dogs with superficial pyoderma without performing bacterial culture and susceptibility testing, the latter being reserved for cases with deep and/or recurrent pyoderma.
The duration of treatment will depend on the depth of the infection. Superficial pyodermas typically need two to three weeks of treatment. Deep pyodermas can be greatly improved after two weeks, but full resolution often takes four to six weeks or longer (Carlotti and Ovaert 1988; Angarano and MacDonald 1989; Guaguère and Marc 1989; Paradis and others 1990; Scott and others 1994; 2006, Carlotti and others 1995).
Treatment has to be continued until the infection is visually and palpably cured, and cytology is normal. It is conventional to continue treatment for another seven days in the case of superficial infections, and14 days if there was deep infection (Scott and others 2001), although the evidence for this is largely anecdotal. Treated cases should be checked every two-four weeks. If there is any doubt that complete resolution has not occurred, treatment should be continued, checking cytology and/or culture to confirm that remission is progressing. It is important to note that the clinical signs associated with an underlying disease may still be present and must be differentiated from the clinical signs of the pyoderma.
Because cephalexin is a time-dependent antibiotic, meaning that it requires concentrations constantly above the MIC to be effective, the suggested dose for cephalexin is 15 to 30 mg/kg orally twice daily ( dermatologists usually recommend dosing at 25mg/kg ) on a full stomach, and the duration of treatment should be three to eight weeks (Mason and Keitzmann, 1999; Scott and others 2001).
Because its absorption is not affected by the presence of food, and in some dogs it can cause vomiting if administered when the stomach is empty, it is usually advised that cephalexin is administered on a full stomach.
When we spoke with practices about cephalexin a lot of vets told us that when they treat larger breed dogs they tend to treat at the lowest dose possible (15mg/kg), in order to keep the cost down to the client. They also commented that clients tend to be less compliant if they need to dose two to three tablets per day to a large dog , therefore you may get sub-optimum dosing because of the lower mg/kg dose and the client then may not dose properly. This is why a lot of the time you can get skin problems which take a long time to resolve, or they get better but come back within a short space of time.
With Tsefalen you can treat at the dermatologist recommended dose (25mg/kg) AND be very cost effective for the client.