Pet Care and Allergy Relief
TITLE: Evaluation of different techniques for washing cats: quantitation of allergen removed from the cat and the effect on airborne Fel d 1
AUTHORS: Avner DB; Perzanowski MS; Platts-Mills TA; Woodfolk JA
AUTHOR AFFILIATION: University of Virginia Asthma and Allergic Diseases Center, Charlottesville 22908, USA.
SOURCE: J Allergy Clin Immunol 1997 Sep; 100(3): 307-12
CITATION IDS: PMID: 9314341 UI: 97457997
BACKGROUND: The purpose of this study was to examine the quantity and distribution of the major cat allergen, Fel d 1, on cats and to evaluate the efficacy
of washing, both in removing allergen from the cat and reducing airborne allergen levels.
METHODS: Airborne samples were collected on four glass fiber filters in a 30 m3 room, before and 3 hours after serial washing of eight cats (45-minute sampling
at 18 L/min for each filter). Aliquots of hair and bath water were also collected and assayed for Fel d 1 content.
RESULTS: Extracting cat hair with tap water or pet shampoo for 3 minutes removed mean levels of 191 and 245 microg of Fel d 1 per gram of hair, respectively;
the quantity of allergen on samples of cat hair ranged from 1 microg/gm to more than 1770 microg/gm. The highest concentration of allergen was found on hair from
the neck. Estimates of the total Fel d 1 on the cat, based on shaving the whole cat, ranged from 3 to 142 mg (mean = 67 mg). Washing cats reduced airborne
allergen 3 hours later. Washing three cats at weekly intervals for 5 weeks in a veterinarian's office produced a mean decrease of 44% in airborne Fel d 1 (n=15, p<0.02).
Washing three cats by immersion for 3 minutes at weekly intervals for a 1-month period produced a mean decrease in airborne allergen levels of 79% (n=12, p<0.001).
However, after repeated washing, the airborne levels before the next wash were not consistently decreased. The quantity of Fel d 1 removed by immersion varied from 1 to 35 mg.
CONCLUSIONS: Cats carry large quantities of Fel d 1, only a small proportion of which (approximately 0.002%/hr) becomes airborne. Washing cats by immersion will remove
significant allergen from the cat and can reduce the quantity of Fel d 1 becoming airborne. However, the decrease is not maintained at 1 week.
TITLE: Washing the dog reduces dog allergen levels, but the dog needs to be washed twice a week.
AUTHORS: Hodson T; Custovic A; Simpson A; Chapman M; Woodcock A; Green R
AUTHOR AFFILIATION: North West Lung Centre, Wythenshawe Hospital, Manchester, UK.
SOURCE: J Allergy Clin Immunol 1999 Apr; 103(4): 581-5
CITATION IDS: PMID: 10200004 UI: 99216454
BACKGROUND: Many asthmatic patients allergic to dogs refuse to part with their dog, and it is essential to develop techniques for lowering
exposure with a dog in the home.
OBJECTIVE: This study investigated the effect of dog washing on the subsequent recovery of Can f 1 from dog hair clippings and on the airborne allergen
over a 7-day period.
METHODS: Dogs, which had not been washed for at least the previous 3 weeks, were washed with a hand-held shower and proprietary shampoo. Hair clippings
and dander samples from 25 dogs were collected before and immediately after washing. After these initial studies, 16 dogs had a small tuft of hair clipped
from the collar or spinal area before washing and then daily for the next 7 days. Air sampling was performed in 5 homes, and the air samples were collected
(airflow rate, 9 L/min) over an 8-hour period per day on 10 consecutive days (3 days of baseline sampling before washing and then 7 consecutive days after washing).
Can f 1 level was measured by using 2-site ELISA.
RESULTS: Washing significantly reduced recoverable Can f 1 from clippings (84% reduction: from 73 microg/g to 12 microg/g [geometric mean]; P<.0001) and from
dander samples (86% reduction: from 347 microg/g to 50 microg/g [geometric mean]; P<.0001). There was a significant reduction in Can f 1 levels in dog hair over
the observed 8-day period (F=18.4, P<.0001). By using a multiple comparison test, this observed significance was found to be due to the difference between the baseline
levels and those on days 1 and 2 after washing, with no difference in the baseline Can f 1 compared with days 3 to 7. Airborne Can f 1 levels showed a downward trend,
which reached statistical significance when the data were grouped into 3 sampling periods as follows: baseline (ie, mean of 3 days before sampling) was compared with
days 1 to 4 after washing (41% reduction, 95% Cl 13%-60%) and days 5 to 7 after washing (61% reduction, 95% Cl 2%-84%; P=.014).
CONCLUSIONS: Washing the dog reduces recoverable allergen from dog hair and dander. The dog needs to be washed at least twice a week to maintain the reduction in
recoverable Can f 1 from its hair. Washing the dog achieves a modest reduction in the level of airborne Can f 1 in homes with a dog.