LA Animal Watch: UCLA EPIDEMIOLOGIST CALLS COUNTY'S FERAL POLICY STATEMENTS FEAR-BASED PSEUDO SCIENCE, IRRESPONSIBLE AND WRONG

SUMMARY OF UCLA'S DR. ACKERMAN'S STATEMENT TO COUNTY'S GAIL VANGORDON:

I was appalled in our previous exchanges that the County would consider

flea-born typhus to be a common disease. I had hoped that that was just

an isolated instance or misunderstanding. However, your responses here

demonstrate that you have no real understanding of public health

research methods and analysis. Your policy regarding feral cats is not

science-based: it is fear-based reliance on old wives’ tales, flawed,

and biased research to justify your extreme prejudice against cats. As

a public health servant, your public statements do a disservice to the

community you serve: they are irresponsible and just plain wrong.

SHE ALSO CALL'S LONGCORE'S PAPER FLAWED. LONGCORE'S MODELING DID NOT INCLUDE ADOPTIONS, NOR WERE COMPARISONS MADE OF NON-TNR COLONIES FOR COMPARISON OF TNR EFFECTIVENESS.

But more unfortunate is the
pseudo-science you use to evaluate public health risks and programs.
You base your judgment of the success or failure of a public health

intervention on nonexistent or questionable data and on a flawed
simulation study. You use and cite statistical results inappropriately,
fail to accurately measure the outcomes you are supposed to be
monitoring, and you don’t even understand the research done by members
of your own department.

Read the complete exchange:

Gail Vangordon wrote:

Hello Dr. Ackerman,

This email is in response to questions you raised regarding an article

in the Sunday LATimes (January 17, 2010) concerning TNR. I was

interviewed by Ms. Yoshino by telephone and initiated the interview with

the statement that all my responses to her questions on free-roaming

cats and the effects of TNR would be based on those colonies within Los

Angeles County that we monitor, and that I would not be able to respond

to general questions regarding the practice of TNR. The most significant

statement I made during the interview related to our policies regarding

free-roaming cats and was not included in the article. In effect, the

practice of TNR, whether it is effective in reducing the size of

free-roaming cat colonies, is not a debate we willingly engage. Our

concerns lie only in the public health risks related to the accumulation

of feces and flea infestations that occur in association with colonies

of free-roaming cats.

I’ll respond to each of the issues you raised:

You wrote: VanGordon is quoted as saying that TNR has been

"'collectively ineffectual' and that all county-monitored colonies had

significantly increased in number." This is news to me.

For approximately the last 6 years, my Program has routinely monitored

4 colonies of free-roaming cats that reside on County properties and

public areas: Rancho Los Amigos Rehabilitation Center (RLARC),

Harbor-UCLA Medical Center, White Point Beach, and Cabrillo Beach.

Visits to these sites are scheduled once or twice yearly or more

frequently if complaints are received. During visits adult and juvenile

cats are counted, the presence of fecal material and/or fleas is noted,

the number and condition of feeding stations are recorded, and

interviews are conducted with maintenance staff and life guards, if

present. We have noted the following over this period:

o The total number of cats observed increases from year to year

o The total number of feeding stations increases from year to

year

o Monitoring of RLARC and Harbor-UCLA has revealed 1 to 3 new

litters of kittens at each site for the past two years

o In almost all cases, fecal removal is infrequent at best, and

fleas are present from late spring to early fall in areas frequented by

the cats.

We attribute the observed increases in monitored colonies to

ineffective trapping by care takers who are unable to trap all intact

cats within the colony, or keep pace with newly introduced individuals.

You wrote: All of the published studies have shown that feral colonies

managed by TNR actually shrink over time unless there is an influx of new cats.

In the past 2 years, the downturn in the economy has forced many families

to abandon their cats (and dogs), and those abandoned cats have entered

existing colonies. In many cases these former pets are already spayed

and neutered so that even if the number of animals increases slightly

due to the influx of former pets, the colonies are not breeding.

We do not argue the fact that if all members of an original colony have

been spayed or neutered, there will be no breeding by these individuals.

Our concerns relate to the influx of intact individuals and the

considerable size of the colonies we monitor. As an example, the most

recent surveillance conducted at each of the hospital campuses indicated

a minimum of 100 adult and juvenile cats in residence, although

maintenance personnel who were interviewed estimated a much higher

number. Grounds staff were also able to direct my staff to areas of the

campus where young cats from previous litters could be observed.

To successfully reduce colonies of this magnitude, a strict trapping

regimen must be an integral part of the management process. As

accurately referenced in the article, mathematical models of feral cat

populations indicate that 71–94% of a population must be neutered for

the population to decline, assuming there is no immigration. Although

the cats on the 4 monitored sites receive regular care in the form of

food and water, we have never observed attempts by care takers to

systematically conduct a disciplined trapping protocol that would

effectively offset the effects of intact individuals entering the colony

or reproduction by intact females.

You wrote: It is irresponsible for a public official to make such a

sweeping statement that contradicts the published scientific evidence. If you

have evidence that TNR isn't working in LA County, you should share it

with members of the scientific community who are trained to critically

evaluate it. I am committed to insuring that County policies - and the

words and actions of County staff - are consistent with scientific evidence.

As prefaced above, although our observations and the statements I

provided for the article reflect our experience related only to

monitored colonies, the results of our surveillance accurately reflect

those data published in numerous peer-reviewed journals. As a matter of

note, we make it a point to verify the literature we maintain in our

Program reference library and the data we rely upon are only published

in peer-reviewed journals.

You wrote: If the numbers have "significantly increased", what does

that mean? What is the comparison group?

There is no comparison group; our intention is not to assess the

effectiveness of TNR, only to evaluate the conditions associated with

the presence of the cats. As an example, during the monitoring period,

the observed population at RLARC has increased from 70 to 100.

Statements from care givers and grounds maintenance staff placed the

population at 120. Despite efforts by SCA to trap and remove cats in

anticipation of the demolition of structures on the south campus, our

counts and population estimates by campus staffs have remained

relatively unchanged. During the monitoring period we have consistently

observed excessive accumulations of fecal material and active flea

infestations during the summer months in areas frequented by the cats.

You wrote: What would the numbers be if there were no TNR efforts?

These are the kind of questions we should be asking when evaluating such

an intervention. If TNR isn't working here as it elsewhere than we

should be trying to understand why it isn't working.

During the interview I referred Ms. Yoshino to the web site where our

policies have been posted. I stated that Public Health can not, and

will not, engage in the debate as to the effectiveness of TNR as a

management practice. Our policies relating to free-roaming cats refer

specifically to the potential public health risks associated with fecal

accumulations and the presence of fleas. Whether TNR can reduce a

colony over a period of 3 years or 10 years is not at issue. Our stance

must be clearly stated: without the rigorous and systematic removal of

all fecal accumulations associated with a colony and the effective

elimination of fleas both on the cats and in the associated environment,

any colony, regardless of its size, will continue to present a public

health risk.

Thank you for the opportunity to restate our perspective and clarify

the issues you raised. Unfortunately, when a 20-minute interview is

reduced to a single paragraph with two sentences, a great deal of

information is lost.

Gail VanGordon, R.E.H.S., MS

Los Angeles County Dept of Public Health

Chief, Vector Management Program

Public Health Entomologist

5050 Commerce Drive

Baldwin Park, CA 91706

Office: (626) 430-5450

Fax: (626) 813-3017

To:	Gail Vangordon , Angelo Bellomo

Subject:	Re: TNR programs - LA County Public Health

RESPONSE FROM UCLA EPIDEMIOLOGIST, DEBORAH ACKERMAN

Thank you, Ms. VanGordon.

While this information does help me see the problem from your

perspective as a vector control manager, it raises additional questions.

Since you have repeatedly stated that your concern is not the numbers of

cats in the colonies but the amount of fecal material and fleas, I would

like to know how you measure those amounts. As you know, to evaluate an

intervention requires data. So I’d like to know what you are measuring

and how those measurements have changed or not since TNR programs were

adopted at the colonies you monitor. Again, I ask you for the data upon

which you based your conclusion that TNR is “collectively ineffectual.”

By that I am assuming you mean it is ineffectual in reducing feces and

fleas.

You continue to exaggerate the public health risks associated with

exposure to the feces of feral cats. Despite the frequency with which

infected patients have household pets, pets have rarely been implicated

as the source of these infections. With regard to toxoplasmosis, where

causal analyses have been performed, the leading cause of infection is

eating undercooked meat. Other cases had been exposed to infected feces

of their own pet cats. Infection from oocysts in cat feces requires

close contact with infected animals. The same is true of other

intestinal parasites: for cross-infections to occur close contact is

necessary.

You assert that your goal is the “removal of all fecal accumulations

associated with a colony.” This is a ridiculous goal that makes no

sense scientifically in light of the findings of species and genotypes

of Cryptosporidium and Giardia (see early review by Hunter and Thompson,

2005). Molecular epidemiologic studies of Cryptosporidium and Giardia

transmission by Cacciòa et al. (2005), Thompson et al. (2008), Xiao and

Fayer (2008), Ballweber et al. (2009), and many others conclude that the

public health significance of infections in domestic animals is not as

great as previously thought. There is considerable genetic diversity

among isolates of the same species of Giardia and Cryptosporidium,

suggesting that these species are in fact species complexes and that

some of these are host-specific. Dogs and cats are commonly infected

with the C. canis and C. felis while human infections are most often

associated with C. parvum and C. homini. Similarly, genotyping and

subtyping data suggest that zoonotic transmission is not as prevalent in

the epidemiology of giardiasis. In fact these researchers, many who

work for the World Health Organization, indicate transmission may be

anthroponotic (humans are the reservoir) rather than zoonotic!

In addition, numerous recent surveillance studies have found the

prevalence of these intestinal parasites in cats is low. An examination

of fecal samples from 384 cats in 4 northern California shelters found

the overall prevalence of Giardia spp. and Cryptosporidium spp. to be

9.8 and 4.7%, respectively. In New York State, an examination of fecal

samples from 263 kittens also found the prevalence of these parasites to

be low: Giardia, 7.3% and Cryptosporidium, 3.8%. Do you have data that

show the prevalence of these parasites among cats in LA County is

significantly higher to justify the requirement that all fecal material

be removed?

Feral cats contribute less than you imagine to environmental fecal

accumulations. I refer you to a 2006 study by Dabritz et al., which

estimated that pet cats allowed to roam were responsible for 72% of

outdoor fecal mass from cats. She didn't estimate the fecal mass

attributable to dogs, but dogs only defecate outside. So the outdoor

fecal mass associated with a particular colony is the result of both

free-roaming and feral cats, as well as dogs and also wildlife. In

fact, the CDC has attributed dog feces as the leading source of

infections from these intestinal parasites. What are you doing to

protect the public from exposure to dog feces? Or bird feces and the

feces of other wildlife, etc?

If people are at greater risk of infection from intestinal parasites in

the feces of feral colonies, you would expect to see a higher incidence

of giardiasis or cryptosporiadiosis infections in the colony

caregivers. Yet none of the workers I interviewed has ever gotten sick

with these diseases. From an epidemiologic standpoint, consider the

City of Berkeley which vigorously promotes TNR. The incidence of these

diseases is the same in Berkeley as it is in Los Angeles: in 2008 there

were 9 cases of giardiasis per 100,000 residents and 10 cases per

100,000 in LA; similarly there was 1 case of cryptosporidiosis per

100,000 Berkeley residents and 1 case per 100,000 residents of Los

Angeles. Thus the fecal mass associated with feral colonies makes no

difference in the rate of these parasitic infections.

With regard to your concerns about the public health risks associated

with fleas, I must again remind you of our discussions in October. The

risk of flea-born typhus is extremely low, so low that Dr. Helene

Calvet, the Long Beach Health Officer, is quoted as saying, "This is a

rare disease.... The vast majority of the population is not going to

come in contact with this disease or come down with it." (The full

article is posted on the FoxLA web site,

http://www.myfoxla.com/dpp/health/eight_recover_from_typhus_in_long_beach_20091024.)

Furthermore, the causal analysis of cases of murine typhus in LA County

by Sorvillo et al. (1993) found that pet ownership was the greatest risk

factor (OR=6.9, CI=1.8-25.9, p=0.002) and that 90% of pet cats compared

with only 11.5% of neighborhood cats were seropositive for typhus. As

you know, seropositivity indicates exposure of animals to fleas infected

with typhus. The conclusion is that flea-born typhus is a rare disease

and if people get sick they most likely become infected from fleas on

their own cats (or dogs) rather than from cats in the neighborhood. To

repeatedly call fleas from feral cats a public health risk is contrary

to the evidence from your own department. The risk of infection is from

fleas on pet cats (and dogs).

You have also stated that, even though you are not concerned with

numbers, you are obtaining counts of the numbers of cats and litters at

each site. And you are quoted as saying that those numbers have

“significantly increased.” Statistical tests require either a parallel

comparison group or a before-and-after comparison in the same

population. Do you mean the numbers have increased since before TNR was

initiated? Are your statistical analyses comparing current numbers with

the historical numbers of cats before TNR? What are the historical

numbers that you are using for your before and after comparisons? How

many litters per year were there in the colonies before TNR? Again, I

ask you for the data you are using to base your conclusion that the

numbers have significantly increased in the colonies you are

monitoring. You suggest that up to 3 litters a year in a colony of 100

cats is proof that TNR isn’t working. How many litters do you think

there would be if none of the cats were sterilized? Just one intact

female cat can produce 3 litters or more a year and more than 600,000

offspring during her lifetime. Without accurate counts of cats and

litters and a comparison group, either historical or parallel, it is

impossible for you to draw any conclusion about the effectiveness of TNR.

For your information and education, the following are appropriate and

accurate data from Harbor that I obtained by interviewing the primary

caregiver. Caregivers are the only accurate source of this type of data

because they feed the cats at night, when the cats are out, and they get

to know each animal. Before TNR began in earnest at Harbor there were

at least 100-150 cats, and may have been as high as 300. The hospital

would trap and remove them every 6 months, and during each 6-month

interval the number of cats and kittens doubled or tripled. Currently

there are 52 cats at Harbor. The caregiver feeds them at night and

returns 1 hour later to remove the dishes. Each year there are 4-6

newcomers who are removed, spayed or neutered, and adopted out. Many of

the newcomers are intact, and many of these are pregnant females. Last

year there were 2 litters. In other recent years there have been 0

litters. All kittens are removed for adoption and the mothers are

removed, spayed, and put up for adoption. You mention counting the

number of feeding stations. There are none at Harbor except for 1 hour

each night. What does that number tell you about the size of the

colony, number of fleas, or the amount of fecal material? At Harbor,

the agreement is that Harbor removes the fecal material and controls

fleas in its buildings and the caregiver adds "Program" to the cats’

food once a month to control fleas on the animals. If and when special

situations arise, the caregiver and the hospital work together. For you

to state on the record that TNR is “collectively ineffectual” is just

plain wrong and does a disservice to the ongoing and successful

partnership between Harbor and the team of caregivers.

I also interviewed the caregivers at Cabrillo, White Point, and Rancho

Los Amigos where similar successes can be demonstrated. At Cabrillo

before TNR there were about 40 cats and now there are 20. There hasn’t

been a litter in 3 years. Last year there were 2 newcomers, abandoned

cats, who were trapped, neutered, and put up for adoption.

At White Point there were substantially more than 100 cats when they started TNR

in 1995. In 2001 the caregivers and other volunteers at their own

expense had the cats’ blood and feces tested and the results were

presented to staff of the Public Health department, who concluded that

the cats posed no health risk to the public. Currently there are 55

cats. There was 1 litter last year, and all the kittens were removed,

spayed/neutered, and put up for adoption. Each year they receive about

8 drop-offs, which are all spayed/neutered and if possible put up for

adoption. The cats are fed daily, and the feces are removed daily. To

control fleas, the cats are treated with Program twice a year or

regularly with Advantage. Sick animals are trapped and treated or

euthanized if necessary.

Historically at Rancho there were 150-200 cats. Many were cats who had escaped from the Downey shelter in 2008. There are now 70 cats. There was 1 litter this past year and the kittens were removed for adoption and the mother was trapped, spayed,

and removed. Several newcomers were similarly trapped, spayed/neutered,

and put up for adoption. To appropriately monitor these colonies, you

need to interview the caregivers. They are truly field researchers who

document their work. Stray Cat Alliance and the other caregivers, all

dedicated volunteers, are dismayed that you continue your obvious

vendetta against the cats with total disregard for the actual data.

Despite the fact that you are not interested in numbers of cats, you

cite estimates provided by simulation models of the number of

sterilizations required for TNR to be successful (in terms of numbers of

cats). However, simulation studies of the type you mention can never

accurately predict the future of a specific colony. We would need to

know: 1. what the colony growth rate would be if all animals were

intact; 2. the rate of immigration of intact animals entering the

colonies; and 3. the rate animals are adopted out of colonies. The

paper you mention is severely flawed because it does not include

adoption rates in its simulations, and yet adoption out of colonies has

been shown to be an important component of successful TNR programs.

Thus this model overestimates the proportion of animals that must be

sterilized.

I would like to point out the public health benefits of TNR programs.

By reducing the proportion of intact animals it slows the colony growth

rate and thereby slows the accumulation of feces. TNR also removes sick

cats from the environment and through vaccination it increases the

proportion of healthy animals so that any risk of disease transmission

to humans is also lowered. To achieve the goal of smaller (and

healthier) colonies that do shrink overtime along with the fleas and

fecal mass, it seems that a coordinated effort is needed that requires

support for TNR programs and the caretakers. In addition, the influx of

new cats must be slowed or stopped by encouraging responsible pet

ownership (to discourage animal dumping) and by mandatory spay and

neuter laws. Most importantly from a public health perspective, pet

owners must be made aware of the need for flea control, proper

sanitation, and good hygiene.

None of us wants large populations of cats living in the streets.

However, trap and remove has not been found to be effective. As was

observed at Harbor and elsewhere, intact females will continue to breed

and other animals will move in as long as the environment supports a

certain population size. As long as more pets are born than can be

adopted, there will always be abandoned animals and there will always be

humanitarians who feed them. TNR is an important component of the

solution.

It is unfortunate that Ms. Yishima chose to include only a small part of

your discussion and not your disclaimer that you are only interested in

the fleas and feces of feral cats. But more unfortunate is the

pseudo-science you use to evaluate public health risks and programs.

You base your judgment of the success or failure of a public health

intervention on nonexistent or questionable data and on a flawed

simulation study. You use and cite statistical results inappropriately,

fail to accurately measure the outcomes you are supposed to be

monitoring, and you don’t even understand the research done by members

of your own department. You may very well have a whole library of

reference material, but if no one knows how to interpret the studies,

what good are they in informing your policies?