Program Flea Control:
a new weapon in the fight against Ringworm

by Hellery Spear

In November 2000, perhaps the most exciting and encouraging news
in many years
was announced concerning the battle against Ringworm

A report published in the Journal of the American Veterinary Medical Association indicated that the flea killer medication, Program, (Lufenuron) appeared to be affective against fungus, and in particular Ringworm (Microsporum canis), in infected dogs and cats.

Traditionally, fungal infections have been treated with the drugs griseofulvin and ketoconazole.

Program is used in veterinary medicine as a flea control treatment, administered orally once per month.

This is an exciting discovery that may mean Program will become the single best ringworm killer/control that has yet to be discovered.

PROGRAM is easy to administer - just a single pill given orally once a month.

And it is inexpensive, and available without prescription.

EFFECTIVENESS Initial reports indicate PROGRAM works quickly, giving negative cultures in as little as 8 days!

DOSAGE: we don't actually know what dosage of Program should be used to treat ringworm. The researchers who published the study picked dosages for convenience, not because they had any scientific reason for choosing those particular dosages.

Although the dosage in the study was somewhat higher than that used for flea prevention, Dr. Susan Little, our resident feline expert and veterinarian, has decided to use Program for ringworm at the labelled dosage until we have more information.

SAFETY:Programexhibits no drug interactions, so is safe for use on older pets, pets with liver or renal problems, or pets on any medication for diabetes or antibiotics. There is no bio-accumulation so there is no chance of lufenuron "building up" in the pet and causing a problem in the long term. It appears to be safe for use on kittens as young as 8 weeks well as pregnant and nursing queens.

As you can see, it may be that lufenuron and Program may well emerge as an important option for treatment of ringworm in cats.

Below are excerpts taken from the original article published in the JAVMA, Vol 217, No 10, November 15, 20000

Use of Lufenuron (Program) for treating fungal infections
of dogs and cats: 297 Cases (1997-1999)

Objective:To evaluate use of Lufenuron for treating cutaneous fungal infections in dogs and cats.

Design: Retrospective Study Procedure-Medical records were reviewed for dogs and cats that had been treated for dermatophytosis and for other fungal infections by administration of lufenuron and 18 dogs and 42 cats that were not treated and served as a control group.

Results: Cats were treated once by oral administration of lufenuron suspension in doses ranging from 51.2 to 266 mg/kg (23.3 to 120.9 mg/lb). Samples were obtained daily from 23 cats: mean durations from time of treatment to time of negative fungal culture results and resolution of gross lesions were 8.3 and 12 days, respectively. Time to resolution of lesions in most untreated control animals was approximately 90 days. Adverse effects of treatment were not detected.

Conclusions and Clinical Relevance: Results of this study suggest that lufenuron provided an effective, convenient and rapid method of treating fungal infections in dogs and cats. (J Am Vet Med Assoc 2000:217:1510-1513) Dermatophytes are classified on the basis of their morphologic characteristics and include morphologic characteristics and include Microsporum, Trichophyton, and Epidermophyton spp all of which are pathogenic for humans and animals. Three species, M canis, M gypseum and T mentagrophytes cause most clinical cases of dermatophytosis in dogs and cats. Microsporum canis is the most common cause of ringworm and is transmitted from cats and dogs to humans. Spontaneous remission of dermatophytosis in companion animals often occurs within 1 to 3 months, whereas treatment is undertaken to reduce transmission to other animals, including human, and eradicate the infection. Dermatomycoses that affect companion animals include nondermatophytic superficial fungal infections with organisms such as Aspergillus, Candida, Malassezia and trichosporon spp.

Lufenuron is classified as an insect development inhibitor because of its ability to inhibit chitin ( a polymer of n-acetylglucosamine) synthesis, polymerization, and deposition.

Results: 357 dogs and cats met study criteria. Sixty animals were untreated controls and 297 animals with fungal infections had been treated with lufenuron.

Of the cats, 71 were males, and 88 were females. 145 of these cats were mixed-breeds, 8 were Siamese, 7 were Persians, 1 was an Angora, and 1 was a Himalayan.

Ages ranged from 2 to 128 months (mean, 16.2 16 months) and body weight ranged from 0.55 to 5 kg (1.2 to 11 lb; mean 3.1 l.l kg; 6.8 2.4 lbs).

One hundred fifty-six cats were infected with M canis and 18 of these cats had generalized infection. Three cats were infected with T mentagrophytes. Lesions were located on the head and neck (n=136), limbs (10) trunk (7), and tail (6).

In these treated cats, hair started to regrow after 5 or 6 days, and full growth was usually completed within 10 to 12 days. Mean clinical recovery time was 11.6 1.4 days.

Of the 18 cats with generalized M canis infection, 14 recovered within 10 days, 2 recovered within 11 days, and 1 recovered within 14 days. One 2 month old Persian kitten did not recover, even after 20 days.

Of the 23 cats examined individually on a daily basis by use of fungal culture, mycologic cure was detected within 7 to 14 days (mean, 8.3 1.2 days), whereas clinical recovery was complete within 10 to 15 days (mean, 12 1.8 days).

In one cat, positive culture results were obtained again 35 days after treatment; a second treatment was administered, and negative culture results were obtained for the next 8 weeks.

Three cats again developed clinical signs of infection several weeks after initial remission of clinical signs; M canis was cultured from the lesions, and the cats responded well to a second treatment of lufenuron.

Discussion: Results of the study reported here indicated that dermatophytosis persisted for 2 to 3 months in untreated animals, whereas dogs and cats that were treated with lufenuron had remission of clinical signs much more rapidly: approximately 10 to 15 days for cats and 16 to 25 days for dogs. Furthermore, mean recovery times of dogs affected by superficial dermatomycoses were quite similar. Evaluation of results of daily mycologic culture of specimens from 16 treated dogs and 23 treated cats permitted a comparison of mycologic cure and clinical recovery times in these animals. In all instances, culture results were negative before clinical signs had disappeared. Differences in duration between these 2 findings ranged from 1 to 19 days for dogs and 1 to 5 days for cats.

Lufenuron appeared not to have adverse effects.

Kittens that weighed as little as 0.5 kg received an entire tube (133mg) of the drug equivalent to a dose of 266 mg/kg, which is considerably larger that that typically administered for flea control, with no apparent adverse effects.

Nevertheless, approximately 5% of treated animals became reinfected including 1 dog and 1 cat that were monitored daily by use of fungal culture. Infections reappeared at 25 to 35 days after treatment, respectively, and were successfully treated with a second dose of lufenuron. It is not known whether these animals had become reinfected by natural exposure or were latently infected despite treatment.

Nevertheless, oral administration of lufenuron appears to be effective treatment for certain cutaneous fungal infections in dogs and cats.

For the complete text of this article, refer to
JAVMA, Vol 217, No 10, November 15, 2000

Normal pesticides and other prescription drugs have to be tested for an LD50. This is the recognized dose in animals where the drug turns toxic in 50% of laboratory rats. It was not possible to establish an LD50 for PROGRAM.


Copyright © 2001 All Rights Reserved
Copying or redistribution of this article is strictly prohibited without the
express written permission of

Website Designed & Maintained by
ShowCatsOnline Web Design

We'd love to design YOUR cattery website