Dirofilaria immitis is the causative agent of canine and feline heartworm disease. Adult worms live in the pulmonary arteries, and females produce first-stage larvae (microfilariae), which are taken up by mosquitoes that then transmit the infection to other animals. In dogs, an untreated infection leads to congestive heart failure (Figures 1 and 2). D. immitis, like most filarial worms studied to date, harbor bacteria called Wolbachia, which are thought to play an essential role in the biology and reproductive functions of their filarial hosts.Wolbachia pipientis, the only species thus far identified in the genus, are gram-negative bacteria belonging to the order Rickettsiales (just like Ehrlichia spp and Anaplasma spp).

1. A NEWSLETTER OF PRACTICAL MEDICINE FOR VETERINARY PROFESSIONALS
SEPTEMBER 2006 VOLUME 4, NUMBER 3
Wolbachia and
Heartworm Disease
Laura H. Kramer, DVM, PhD, DEVPC
College of Veterinary Medicine
University of Parma, Parma, Italy
Dirofilaria immitis is the causative agent developing embryonic stages within the Wolbachia increases its own fitness by
of canine and feline heartworm disease. uteri. This suggests that the bacterium is increasing the fitness of the host
Adult worms live in the pulmonary vertically transmitted through the involved in its transmission.
arteries, and females produce first-stage cytoplasm of the egg.1 s Removal of Wolbachia (via antibiotics
larvae (microfilariae), which are taken up or radiation) leads to sterility of female
by mosquitoes that then transmit the ROLE OF WOLBACHIA IN worms and eventual death of adults.
infection to other animals. In dogs, an ITS FILARIAL HOST
untreated infection leads to congestive Human research has revealed several It is still unclear, however, exactly what
heart failure (Figures 1 and 2). D. immitis, reasons why the presence of Wolbachia is Wolbachia does to make it so important
like most filarial worms studied to date, thought to be essential for a filarial for its filarial host. It has been suggested
harbor bacteria called Wolbachia, which are worm’s survival: that, while the filarial worm likely supplies
thought to play an essential role in the s the bacteria with amino acids necessary
In those species of filarial worms that
biology and reproductive functions of their for growth and replication, Wolbachia may
have been identified as harboring
filarial hosts. Wolbachia pipientis, the only produce several important molecules that
Wolbachia, all of the individuals are
species thus far identified in the genus, are essential for heartworms, such as
infected (i.e., 100% prevalence).
are gram-negative bacteria belonging to glutathione and heme.2 It is indeed a “one
s The evolution of the bacteria matches
the order Rickettsiales (just like Ehrlichia hand washing the other” situation that
spp and Anaplasma spp).1 In adult D. that of the filarial worms, and
immitis, Wolbachia is predominantly found phylogenic studies have shown that
throughout cells in the hypodermis, which the two organisms have been “walking
is directly under the worm’s cuticle (Figure hand-in-hand” for millions of years. ALSO IN THIS ISSUE:
3). In female D. immitis, Wolbachia is also s The bacteria are transmitted from Deworming Demystified............ 4
present in the ovaries, oocytes, and female to offspring and, in this way,

2. A NEWSLETTER OF PRACTICAL MEDICINE FOR VETERINARY PROFESSIONALS
SEPTEMBER 2006 VOLUME 4, NUMBER 3
Consulting Editors
Albert Ahn, DVM
Vice President of Corporate
Communications and Consumer
Relations
The Hartz Mountain Corporation
Figure 2. Radiograph of the dog Bruce Truman
in Figure 1. Note the enlarged cardiac
Senior Director
Figure 1. A 6-year-old Great Dane chambers (white arrows), thickened
Animal Health and Nutrition
with chronic heartworm disease. Note the pulmonary arteries (yellow arrow), and
weight loss (apparent by the noticeable interstitial inflammation. (Photo by Dr. Luigi The Hartz Mountain Corporation
spine and rib cage) and dilated abdomen Venco)
(due to ascites). (Photo by Dr. Luigi Venco)
Associate Editors
disease. Bacteria were observed in the Jill A. Richardson, DVM
may, however, be the key to novel lungs and particularly in organs where Director
strategies for the control/treatment of microfilariae normally circulate, such as the Consumer Relations
filarial infection, including canine and kidney and liver. Furthermore, when we The Hartz Mountain Corporation
feline heartworm disease. looked at specific antibody responses to David Levy
Wolbachia, we observed a stronger response Assistant Manager
ROLE OF WOLBACHIA IN in dogs with circulating microfilariae Animal Health and Nutrition
THE INFLAMMATORY AND compared with dogs with occult infection, The Hartz Mountain Corporation
IMMUNE RESPONSE IN D. supporting the hypothesis that microfilarial
HARTZ® COMPANION ANIMAL SM
IMMITIS–INFECTED ANIMALS turnover is an important source of
Wolbachia in dogs with heartworm disease. is produced for The Hartz Mountain
As gram-negative bacteria, Wolbachia
Corporation by Veterinary Learning
have the potential to play an important role Furthermore, Wolbachia from D. immitis
Systems, 780 Township Line Rd.,
in the pathogenesis and immune response have been shown to provoke chemokinesis Yardley, PA 19067.
to filarial infection. The possible and proinflammatory cytokine production
consequences of the massive release of in canine neutrophils. Cats with Copyright © 2006 The Hartz Mountain
Wolbachia in the filaria-infected host have heartworm disease also produce antibodies Corporation. All rights reserved.
been evaluated. Wolbachia are released both to Wolbachia. Interestingly, it has recently Hartz® and other marks are owned by
by living worms and after worm death been reported that the development of a The Hartz Mountain Corporation.
through natural attrition, microfilarial strong antibody response against D. immitis
occurs after 1 to 2 months of infection, Printed in U.S.A. No part of this
turnover, and pharmacologic intervention.3
publication may be reproduced in any
In human and murine models of infection, which has important implications for early
form without the express written
the release of bacteria has been shown to diagnosis.5 permission of the publisher.
be associated with the up-regulation of Areas of future research should include
proinflammatory cytokines, neutrophil the possible diagnostic use of specific For more information on The Hartz
recruitment, and an increase in specific immune responses to Wolbachia, its Mountain Corporation, visit
potential immunomodulatory activity www.hartz.com.
immunoglobulins. Ongoing studies in dogs
with heartworm disease may shed light on (prevention), and the effects of antibiotic
what happens when infected animals come treatment in infected animals. synthetic derivatives appear to be the
into contact with the bacteria. For example, most effective) are able to drastically
my colleagues and I recently tested the EFFECT OF ANTIBIOTIC reduce if not completely remove the
hypothesis that D. immitis–infected dogs TREATMENT ON FILARIAL endosymbiont from the worm host. Such
come into contact with Wolbachia either WORMS depletion of Wolbachia is then followed by
through microfilarial turnover or natural Wolbachia can be eliminated from clear antifilarial effects, including:
death of adult worms.4 In our study, filarial worms through antibiotic therapy
positive staining for Wolbachia was of the infected host. Numerous studies s Inhibition of larval development:
observed in various tissues from dogs that have shown that various treatment It has been shown that antibiotic
had died because of natural heartworm protocols and dosages (tetracycline and treatment of filaria-infected hosts can
2 HARTZ COMPANION ANIMAL
® SM
• SEPTEMBER 2006 • VOL. 4, NO. 3

3. ADDITIONAL CONSIDERATIONS FOR ADULTICIDE
THERAPY—WOLBACHIA
Most filarial nematodes, including D. immitis, harbor obligate, intracellular, gram-
negative bacteria belonging to the genus Wolbachia (Rickettsiales). In infections with other
filarial parasites, treatment with tetracyclines during the first month of infection was lethal
to some Wolbachia-harboring filariae but not to a filariae that did not harbor Wolbachia,
and treatment of Wolbachia-harboring filariae suppressed microfilaremia. Similar
prophylaxis studies with D. immitis have not been reported, but in one study, tetracycline
treatment of heartworm-infected dogs resulted in infertility in the female worms. These
bacteria also have been implicated in the pathogenesis of filarial diseases, possibly through
Figure 3. Cross–section of an adult
female Dirofilaria immitis stained with a their endotoxins. Recent studies have shown that a major surface protein of Wolbachia
polyclonal antibody against the Wolbachia (WSP) induces a specific IgG response in hosts infected by D. immitis. It is hypothesized
surface protein. Note the numerous that Wolbachia contribute to pulmonary and renal inflammation through the surface
bacteria (arrows) that almost entirely fill protein WSP independent of its endotoxin component. Studies to determine the effects
the cell of the lateral hypodermal cord.
of suppressing Wolbachia populations with doxycyline prior to adulticide therapy will be
(Original magnification x40)
required to determine the clinical utility of this therapeutic approach.
inhibit molting, an essential process From: Guidelines for the Diagnosis, Prevention and Management of Heartworm ( Dirofilaria immi-
tis) Infection in Dogs; reprinted with permission of the American Heartworm Society. Available
in the maturation of worms from at www.heartwormsociety.org; accessed August 2006.
larvae to adult.
s Female worm sterility: Antibiotic
treatment leads first to a reduction ultrasonography in 21 of 27 patients. worm. There are little data concerning the
and then to the complete and In the other patients, the number of effects of antibiotic treatment in dogs with
sustained absence of microfilariae. scrotal worm nests declined. This was natural heartworm disease; what is known,
Researchers at the University of significantly different from placebo however, is that such treatment drastically
Milan, Italy, have reported that D. patients in which lack of worm nests reduces Wolbachia loads in D. immitis.
immitis adults taken from naturally was only observed in three of 27 Preliminary trials8 in naturally infected
infected dogs that had been treated patients. This is the first report of dogs have shown that doxycycline treatment
with doxycycline at 20 mg/kg/day antibiotic-induced adulticide activity before adulticide therapy with melarsomine
for 30 days showed morphologic in a human filarial worm. Could may help reduce proinflammatory reactions
alterations of uterine content with a antibiotic treatment have the same due to the death of adult worms (as seen
dramatic decrease in the number of effect on D. immitis? Several research by lower antibody levels against Wolbachia
mature microfilariae, indicating that groups, including our laboratory, are and lower levels of interleukin-8, an
bacteriostatic antibiotic treatment curently attempting to answer this very inflammatory cytokine involved in
was able to block embryogenesis.6 important question. neutrophil recruitment). These results have
s Adulticide effects: This is a particularly encouraged our laboratory to continue to
intriguing aspect of antibiotic treatment EFFECTS OF ANTIBIOTIC evaluate the clinical benefits of antibiotic
of the filarial worm–infected host and TREATMENT ON THE FILARIAL treatment in naturally infected dogs.
one that merits strict attention. Clinical WORM–INFECTED HOST Given the recent and very promising
trials in human filariasis have reported It is very likely that antibiotic treatment developments in the use of tetracyclines
extremely promising results: A recent will have some beneficial effects on subjects for micro- and macrofilaricidal therapy in
placebo-controlled trial in humans with filariasis. First, the effects on the human filariasis, it is hoped that similar
infected with Wuchereria bancrofti has worm (described above) will themselves attention will be given to canine and
demonstrated a clear macrofilaricidal lead to improved clinical presentation, feline heartworm disease, which could
(i.e., adulticidal) effect of doxycycline.7 such as a reduction in the circulating greatly benefit from alternative
When administered for 8 weeks at 200 microfilariae that have been implicated in therapeutic strategies.
mg/day, doxycycline treatment resulted immune complex formation during
in complete amicrofilaremia in 28 of 32 infections.4 However, if Wolbachia is
REFERENCES
1. Bandi C, Trees AJ, Brattig NW: Wolbachia in filarial
patients assessed and a lack of worm considered a potential cause of nematodes: Evolutionary aspects and implications for
nests in the scrotum (where adult inflammation in the course of filarial the pathogenesis and treatment of filarial diseases. Vet
Parasitol 98:215–238, 2001.
worms reside) at 14 months after disease, depletion of the bacteria may be 2. Foster J, Ganatra M, Kamal I, et al: The Wolbachia
treatment, as determined by beneficial independent of its effect on the genome of Brugia malayi: Endosymbiont evolution
(continues on page 8)
HARTZ® COMPANION ANIMALSM • SEPTEMBER 2006 • VOL. 4, NO. 3 3

4. Deworming Demystified:
Update on Deworming Protocols
Byron L. Blagburn, MS, PhD
Distinguished University Professor
Department of Pathobiology
College of Veterinary Medicine
Auburn University
Parasites are important causes of that can eliminate many parasites, often Discretionary Deworming
disease in dogs and cats of all ages (Table including both internal and external Discretionary deworming is based on a
1) but can be particularly important in parasites) (Table 2). The language becomes perceived need to deworm, such as results
puppies and kittens because of their small even more confusing when one considers of fecal examination or other diagnostic
size, developing immunity, and other that some single-entity products have tests (e.g., elevated eosinophil count,
stresses associated with growth and broad-spectrum activity (e.g., pyrantel radiographic evidence of pulmonary
maturation. Young pets are often exposed pamoate, milbemycin oxime) and that parasitism). As the name implies,
to and acquire parasites differently than combining products may or may not discretionary deworming is performed at
older pets. Because of their increased increase the spectrum of internal parasites the discretion of the veterinarian. In my
exposure and susceptibility, they often eliminated (e.g., ivermectin–pyrantel view, discretionary deworming should be
harbor greater numbers of parasites than pamoate versus milbemycin oxime– performed only based on knowledge
mature animals. Heavier parasite burdens lufenuron). gained from history or presenting signs,
place puppies and kittens at greater risk of appropriate diagnostic procedures, or
disease and also lead to higher shedding Strategic Deworming other information sufficient to warrant
rates of fecal stages into the environment. Strategic deworming is the application the use of parasiticides.
Increased environmental contamination of a specific parasite-control strategy
also increases the risk of human exposure based on an individual pet’s age, Targeted Deworming
to zoonotic roundworms and hookworms. environment, and likelihood of exposure Targeted deworming, in my opinion,
This article reviews strategies for to parasites, prevalence of the parasite in is just another term for strategic
deworming dogs and cats. Available question, and geographic region. An deworming. The intent is to “target”
parasiticides now allow important example of strategic deworming would be particular time points based on criteria
parasites to be eliminated safely and deworming puppies at 2, 4, 6, and 8 mentioned above for strategic deworming
pets to be maintained free of parasites weeks of age to control migrating stages (i.e., age, environment, history of prior
throughout their lives. of roundworms and hookworms parasitism or exposure to parasites, and
(discussed below). Additional examples geographic region).
SOME DEWORMING include strategically placed intervals
DEFINITIONS between dewormings throughout the year, Interval Deworming
Several terms have been used to define such as every 6 months or every 3 months Interval deworming is deworming
the various approaches to internal parasite for pets with a seasonal likelihood of pets at specific intervals. The approach
control and the available parasiticides. exposure to parasites or if control of a is similar to strategic or targeted
Deworming terms include “strategic,” specific parasite, such as whipworm, is deworming, but with less attention given
“discretionary,” “targeted,” and “interval,” needed. Strategic deworming may also to specific reasons for selecting time
and parasite control products are identified include a strategy of monthly, year-round, points. Interval deworming is usually
as single entity (one active ingredient), broad-spectrum internal parasite control intended to provide a “safety net,” based
combination (more than one active to improve compliance and take on the presumption that pets are likely
ingredient), narrow spectrum (products that advantage of heartworm preventives to be exposed to parasites but without
are capable of removing one or two or flea-control products with activity specific knowledge of when that exposure
parasites), and broad spectrum (products against important internal parasites. is likely to occur.
4 HARTZ COMPANION ANIMAL
® SM
• SEPTEMBER 2006 • VOL. 4, NO. 3

5. TABLE 1: Common Nematode Parasites of Dogs and Cats
Prevalence/ Site of
Parasite Geographic Development Developmental Diagnostic Procedure/ Zoonotic
(Common Name) Host(s) Location (Adult Worms) Life Cycle Period Stage in Feces Potential
Toxocara canis Dogs High/ Small Infection by embryonated eggs 28–35 days Fecal flotation/non- Very
(canine throughout intestine and transplacental transmission; embryonated eggs high
roundworm) the US larvae undergo liver–lung are 90 × 75 µm,
migration; rodents may serve as subglobular, with
transport hosts; transmammary thick pitted shells
transmission is uncommon
Toxocara cati Cats High/ Small Direct infection by embyronated 38–56 days Fecal flotation/non- Very
(feline throughout intestine eggs and transmammary embryonated eggs high
roundworm) the US transmission; rodents may serve are 65–75 µm;
as transport hosts; larvae may similar to T. canis
undergo liver–lung migration; eggs but smaller
transplacental transmission
apparently does not occur
Toxascaris Dogs Low/ Small Direct infection by embryonated 74 days Fecal flotation/non- None
leonina and throughout intestine eggs; rodents may serve as embryonated eggs
(nonmigratory cats the US; transport hosts; development is are 80 × 70 µm,
roundworm) distribution restricted to small intestine; no slightly oval with a
spotty extraintestinal, transplacental, or smooth shell
transmammary transmission
Ancylostoma Dogs High/ Small Direct infection by ingestion or 15–18 days Fecal flotation/non- High
caninum (canine throughout intestine skin penetration; may undergo embryonated eggs
hookworm) the US; more lung migration; ingested larvae are 70 × 40 µm
common in may mature without lung
warmer migration; rodents may serve as
climates transport hosts; the principal route
of infection is transmammary
Ancylostoma Cats High/ Middle small Direct infection by ingestion or 16–25 days Fecal flotation/non- Low
tubaeforme throughout intestine skin penetration; larvae may embryonated eggs
(feline the US; more undergo lung migration; rodents are 61 × 40 µm
hookworm) common in may serve as transport hosts; no
warmer transmammary or transplacental
climates transmission
Ancylostoma Dogs High in tropical Anterior Direct infection by ingestion or 14–27 days Fecal flotation/non- High
braziliense and and subtropical small skin penetration; larvae may embryonated eggs
(subtropical cats regions/limited intestine undergo lung migration; rodents are 55 × 34 µm; not
hookworm) to Florida and may serve as transport hosts; no easily differentiated
Golf Coast information on transmammary from A. tubaeforme
or transplacental transmission
Trichuris vulpis Dogs High/ Cecum Direct infection by ingestion of 77–84 days Fecal flotation/non- Not
(whipworm) throughout embryonated eggs embryonated eggs thought
the US are brownish, bipolar, to be
and 80 × 30 µm zoonotic
SPECIFIC and by ingestion of paratenic (transport) puppies and kittens requires a strategy to
RECOMMENDATIONS hosts (Table 1). Both roundworms and eliminate parasites as they mature. Both
Puppies and Kittens hookworms may undergo multisystem the Companion Animal Parasite Council
Parasite control in puppies and kittens migrations in puppies and kittens. (CAPC; www.capcvet.org) and the Centers
presents several unique challenges; some Continual infection via multiple routes for Disease Control and Prevention (CDC;
are the result of parasite behavior, whereas and multisystemic migration lead to the www.cdc.gov) recommend deworming
others are the result of host factors and presence of parasites in different stages in puppies beginning at 2 weeks of age and
parasiticidal efficacy. Roundworms and different organ systems during their continuing every 2 weeks through 8 weeks
hookworms, the most common parasites migrations. Because current parasiticides of age; thereafter, puppies can be placed
of young pets, are acquired through are most effective in eliminating the adult on monthly broad-spectrum agents that
several routes: embryonated eggs, milk or stages of roundworms and hookworms in include heartworm and/or flea control and
colostrum, via the uterus and placenta, the intestine, control of these parasites in also possess activity against roundworms
HARTZ® COMPANION ANIMALSM • SEPTEMBER 2006 • VOL. 4, NO. 3 5

6. TABLE 2: Selected Broad-Spectrum Canine and Feline Internal Parasiticides
Host Species:
Chemical Name Product Name Parasites Removed Dosage/Regimen Minimum Age
Pyrantel ®
Hartz Advanced Care™ Rid Worm™ Dog: TC, TL, AC, US 5 mg/kg No minimum age
pamoate Chewable Flavored Wormer Tablets; Discretionary treatment
Nemex™, Nemex™-2 (Pfizer Animal
Health); many others
Pyrantel Drontal® (Bayer Animal Health) Cat: Tca, AT, DC, TT 5 mg/kg praziquantel and 4 wk and >1.5 lb
pamoate– 20 mg/kg pyrantel pamoate
praziquantel Discretionary treatment
Fenbendazole Panacur® C Canine Dewormer Dog: TC, TL, AC, US, TV 50 mg/kg/day for 3 days 6 wk
(Intervet) Discretionary treatment
Febantel– Drontal® Plus (Bayer Animal Health) Dog: TC, TL, AC, US, TV, 10 mg/kg febantel, 5 mg/kg 3 wk and >2 lb
pyrantel DC, TP, EG, EM pyrantel pamoate, and 5
pamoate– mg/kg praziquantel
praziquantel Discretionary treatment
Ivermectin Heartgard® Chewables for Cats Cat: DI (L3/L4), AT, AB 24 µg/kg q30d 6 wk
Ivermectin– Heartgard® Plus Chewables for Dogs; Dog: DI (L3/L4), TC, TL, AC, 6 µg/kg ivermectin and 6 wk
pyrantel Iverhart™ Plus Flavored Chewables AB, US 5 mg/kg pyrantel pamoate
pamoate (Virbac); Triheart® Plus Chewable q30d
Tablets (Schering-Plough Animal Health)
Milbemycin Interceptor® Flavor Tabs® for Dogs Cat: DI (L3/L4), Tca, AT Cat: 2.0 mg/kg q30d Cat: 6 wk or >1.5 lb
oxime and Cats (Novartis) Dog: DI (L3/L4), TC, TL, AC, TV Dog: 0.5 mg/kg q30d Dog: 4 wk or >2 lb
Milbemycin Sentinel® Flavor Tabs® (Novartis) Dog: DI (L3/L4), TC, TL, AC, 0.5 mg/kg milbemycin oxime 4 wk or >2 lb
oxime–lufenuron TV, eggs of CF and 10 mg/kg lufenuron q30d
Selamectin Revolution® (Pfizer Animal Health) Cat: DI (L3/L4), Tca, AT 6 mg/kg q30d Cat: >8 wk
Dog: DI (L3/L4), CF, SS, OC, DV Dog: >6 wk
AB = Ancylostoma braziliense; AC = Ancylostoma caninum; AT = Ancylostoma tubaeforme; CF = Ctenocephalides felis; DC = Dipylidium caninum; DI = Dirofilaria immitis; DV =
Dermacentor variabilis; EG = Echinococcus granulosus; EM = Echinococcus multilocularis; L3 = third-stage larvae; L4 = fourth-stage larvae; OC = Otodectes cynotis; SS = Sarcoptes sca-
biei; TC = Toxocara canis; Tca = Toxocara cati; TL = Toxascaris leonina; TP = Taenia pisiformis; TT = Taenia taeniaeformis; TV = Trichuris vulpis; US = Uncinaria stenocephala.
and hookworms (Table 2). This monthly described for puppies. If pets are not Adult Dogs and Cats
strategy serves two purposes—it helps maintained on monthly broad-spectrum Surveys indicate that dogs and
improve pet owner compliance and agents, annual or semiannual fecal cats remain susceptible to parasites
provides continuous roundworm and examinations using centrifugal flotation throughout their lives, although the risk
hookworm control. It should be noted should be performed. Appropriate of disease diminishes somewhat as pets
that only pyrantel pamoate can be used treatments should then be administered age. Adult dogs and cats are also less
in puppies as young as 2 weeks; other based on results of fecal examinations likely to harbor burdens of intestinal
available agents can be used in puppies (discretionary deworming). roundworms and hookworms that are
and kittens starting at 3 to 4 weeks of age. It is important to remember that pets as large as is seen in puppies or kittens.
If monthly broad-spectrum control are susceptible to and may harbor parasites A number of strategies have been
strategies are not used, an alternative that are not eliminated by broad-spectrum employed to control parasitic infections
strategy of biweekly deworming from 2 heartworm preventives. Examples include in adult pets. Among them are continual
to 8 weeks of age followed by monthly tapeworms, coccidia, and Giardia. These monthly administration of broad-
deworming through 6 months of age can and other parasites drive the need for spectrum heartworm preventives; annual,
be employed. Because of the differences accurate fecal examinations conducted at semiannual, or quarterly use of broad-
in the life cycles of canine and feline regular intervals. The frequency of spectrum dewormers; and discretionary
roundworms, kittens can be treated fecal examinations (e.g., one to four deworming based on results of fecal
biweekly between 3 and 9 weeks and times/year) varies based on the age of examinations. The strategy of
then placed on broad-spectrum agents the pet, prior infection status, and continuous monthly use of broad-
or treated monthly for 6 months as potential exposure. spectrum heartworm products is often
6 HARTZ COMPANION ANIMAL
® SM
• SEPTEMBER 2006 • VOL. 4, NO. 3

7. HARTZ
®
IMPORTA N T NEWS FROM e nation, introdu
ced
k products in th
ian: ing provider s of flea and tic t is registe red by the US
Dear Veterinar one of the lead ™ Drops for Cats. The produc retail
n Corporation, ® be available in
is spring, The Hartz Mountai d Hartz U ltraGuardplus er 12 weeks of
age, and it will
Th t calle kittens ov
secticide produc use on cats and
a new topical in ncy (EPA) for d
l Protection Age harmful fleas an
Environmenta d. protected from
in the weeks ahea make sure that all pets are ent the ca re provided by
stores nationally community – to ort and supplem tz®
the veterinary ts that can supp their pets. Har
ur goal is the same as that of effective, wel l-tested produc no flea and tic k protection on the number of
O
mmitted to offe
ring icans use lp expand
ticks. We are co illions of Amer ners and may he
ely show that m ative for pet ow
veterinarians . Surveys routin ec onomical altern
Cats offers an
us™ Drops for m ectoparasites
.
UltraGuardpl are protected fro
companion animals that enprox,
adulticide, Etof
s s a well-tested l
tive ingredient ula that combine -a-month topica
Well-tested ac ats contains an
all-new form
consumers an ef
fective, once
ps for C t offers
uardplus™ Dro ene. This produc
Hartz® UltraG R), (S)-Methopr er ticks, and mosquitoes. e insecticide
ow th regulator (IG as, flea eggs, de 1
insect pests . Th e feline
and an insect gr ickly to kill fle food crops from
treatment that
works qu to protect ntly availabl
ound the world in another, curre
by governments ar d is an ac tive ingredient er Hartz ® feline topicals
been registered pets in 2004 an one used in form
Etofenprox has ation for use on icide from the
first EPA registr different insect
received its is a completely e use.
t2. Etofenprox story of effectiv
topical produc ch has a long hi other insects .
3
rin). ethoprene, whi flies, ants, and
(phenoth r Cats is (S)-M , mosquitoes,
plus™ Drops fo fight infestatio
ns of fleas
e same series
tz® UltraGuard than 20 years to n underwent th
The IGR in Har used for more Cats formulatio y flea
(S)-Methopren
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aGuardplus
™ Drops for uding veterinar
the Hartz Ultr
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city
products used the EPA’s lo
A registration, required for all
insecticidal
rmined to be in
In orde r to receive EP xicity tests n was dete
ty, and acute to , the formulatio
of efficacy, safe ute toxicity tests ve felines. An
ts. Through the ac events in sensiti
and tick produc 40 CFR 156.62
).
oduce adverse ese
category (Categ
ory IV - oduct can pr owners about th
y insecticide pr to educate pet sages in
study results, an otection is an ongoing effort important mes
ith excellent flea and tick pr blicizes these
u know, even w tely. Hartz pu
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As yo mitment to appropria
ent of our com d tick products
important elem of using flea an efforts. ians to report
d the importance ebsites and other outreach e urge veterinar
health issues an ochures, our w ld they occur, w a week
advertising, co
nsumer br pets, shou day, seven days
adverse event in nsumer Relations 24 hours a
e th e chance of any t Hartz ® Co
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While Hartz se
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ians and pet ow pport.
any incident to us. Veterinar their questio ns and other su
14 for answers to
at 1-800-275-14
Sincerely,
, DVM Services
Jill Richardson and Technical
umer Relations
Director, Cons 33231
l.jsp?Rec_Id=PC
/Detail_Chemica et_igr.htm
esticideinfo.org ents/press.asp?
prm_id=568 ctsheets/factshe
. http://www.p /news_ev s/ingredients/fa
1 PAN Pesticides Database w.sergeants.com pd1/biopesticide
Available at ww w.epa.gov/oppbp
2 Sergeant’s news release. fact sheet. Availa
ble at ww
tection Agency
3 U.S. Environmental Pro

8. WOLBACHIA AND HEARTWORM DISEASE (continued from page 3)
within a human pathogenic nematode. PLoS Biology Immunol Immunopathol 106(3–4):303–308, 2005. endosymbionts Wolbachia. Int J Parasitol 29:
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implemented in regions where of ascarids and hookworms from breeding parasiticides can then be administered
heartworm prevention is necessary for all bitches. These strategies require intense as necessary. Annual fecal examinations
or most of the year. Veterinarians must use of available parasiticides during the and discretionary use of parasiticides are
still conduct fecal examinations to assure gestation period and should be used only especially important in senior pets that
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controlling parasites. It is sometimes agents.
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