Recently, a provider of IVC's ran an advertisement wherein they claimed that their airflow method of delivering and removing air at the top of the cage is superior to that of other IVC manufacturers - Allentown included - who deliver air at the cage level.

This advertisement also inferred that air at the cage level creates unacceptable levels of stress for the animals within.

It's time to clear the air. Not only is air at the bottom an accepted and superior air delivery method, it in no way creates elevated or unacceptable levels of stress. In fact, the safety and efficacy of air at the cage level has been widely validated by the LAS community, as evidenced by the impressive group of industry leaders who have spoken or written about it:

Industry Experts Validate Air at the Cage Level: "As a user of Allentown IVC's since their introduction into the UK, we have continued to have complete confidence in this product. There is no indication of stress caused by the location of the air supply and no evidence of our mice trying to escape from draughts!" Sue Keefe FIAT, DMS "I feel confident in recommending Allentown's air in the cage level system. We have now been using it for 2 years and have found it to be safe for even our most vulnerable animals such as NUDEs and other delicate strains. Breeding performance is excellent and the animals are thriving in this extremely effective method of maintaining our state of the art transgenic strains." Dr. Taz Mc Clintock "...there is no evidence that the air valve causes any stress to the mice housed in the Allentown ventilated racks. We commonly observe mice building their nest directly in front of the valve. If the valve was a stressor, I would doubt that the mice would build their nest directly in front of the valve." Dr. August Henry Battles, Director, Animal Care Services "...cages with air supply near the bottom exchanged air in the cage better and more completely than systems with air supplied in the top of the cage." Robert E. Faith DVD, PhD, DACLAM (Excerpt from LAE editorial, June 2009) Read the Complete Article "In my experience using Allentown Inc. IVC cages, there have been no adverse effects on breeding efficiency. We have over 6000 Allentown IVC cages in a barrier breeding facility and have an excellent breeding efficiency." Richard H. Latt, DVM, DACLAM "After using Allentown caging for years I have not seen any evidence of stress in these animals as a result of the caging." Dr. Fred Quimby VMD, PhD "...to say [air at the cage level] is stressful is one thing, to define it in the absence of a definition of stress or data or findings to support the statement is very unrealistic and creates ambiguity around the issue of stress. I have not seen or observed animals in the [Allentown] cages getting out of the way of the airflows described." Hilton Klein VMD, MS DACLAM, DECLAM

In concert with the preponderance of industry opinion listed above, Allentown also believes strongly in its air delivery method, and here are just some of the reasons why:

When rodents are placed into any cage or housing system they naturally alter the environment within, most notably by warming the air with their body heat, and contaminating it with any particulates they carry on them. Now, as every child learns in school, warm air rises, while cooler air sinks. This is a universally observed and accepted rule of physics. By introducing fresh air at the bottom of the cage and removing it at the top, Allentown creates an airflow system within it's housing that works with this accepted rule of physics. The air that has been both tainted and warmed by the rodents at the bottom of the cage is moved from the area of contamination and away from the rodents in an arc that follows the natural movement of air, producing an environment that is subsequently cleaner, more hygienic, and far more consistent for the rodents and for the researcher.

Housing providers who both remove and introduce air at the top of the cage create an airflow system that works against this natural movement of air. One of several downsides to this practice is the possibility of having fresh air removed before it has an opportunity to cycle through the cage. It's easy to see how this scenario could be detrimental to the health of the rodents within. The Allentown way, where there is significant separation between air-in and air-out, virtually eliminates this possibility.

Allentown also has a more effective mechanism for introducing air than other housing providers: a specially designed air diffuser with a fan-shaped pattern of holes that disperses the air in a more even flow across the bottom of the cage. Introducing air in this way, close to the bedding, has the effect of keeping it drier, longer. In fact, under optimal conditions, Allentown cages can easily go as long as fourteen days - sometimes as long as twenty-one days - before needing a change. And that's at 50-60 ACH! Housing providers who introduce air in the lid can require as much as 70-80 ACH just to reach a fourteen-day cage change rate.

In regard to the claims made by our competitor that introducing air at the cage level is stressful to the animals within, we dismiss this as simply market hype. Allentown has provided upwards of 18,000 IVC racks to hundreds of customers worldwide, including some of the most prestigious facilities in biomedical research. In all of that time, and with all of that product in the field, not a single situation has come to our attention suggesting that air at the bottom is in any way harmful to rodent health.

In fact, the converse is true. Compelling, scientific evidence supports our belief that air at the bottom is a safe and effective ventilation method. Allentown IVC racks were tested by TÜV for compliance with TIZ BIFO standards in the area of velocity, among other areas as well. TÜV concluded that Allentown IVC cages were indeed compliant with the standard and do not exhibit high velocity airflow.