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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 |
