One a month Heartguard versus 6-month shot

[livertw]

I'm always cautious about new products. Daisy just took her last one-a-month heartworm preventive pill. The vet mentioned that there is a 6-month shot available. Has anyone used the shot? What might be the pros and cons? Cost is about the same for the 6-month shot as for six months supply of tablets. :p

[mmgy]

Hey Nancy!!!

I haven't heard anyone "rave" over it, so I'm not inclined to try it, as least not yet. Also, after so many years, I'm in the monthly pill mode......learning a new schedule might be too much stress for my brain!!!

Maybe there will be some testimonial posts after me.

Hi to Daisy!!:D

[lblax]

you save about 15 bucks over 6 months time with the shot

[livertw]

I'd like to save $15...I'll get some actual numbers when I stop at the vet's on my way home tonight.

[Miabella]

I believe there has been controversy with some dogs having reactions to the shot. My vet does not recommend it, and I will continue to give the monthly oral preventative.

[livertw]

I just called the vet and ordered 6 months worth of the once-a-month tablets. I'd rather not worry. Plus I'll have time to do some research (on Rott.net) and be better informed next time.:D

[Miabella]

Fort Dodge Animal Health Steve Connell, DVM
Division of Wyeth Director
9401 Indian Creek Parkway Professional Services
Suite 1500 (800) 533-8536
Overland Park, KS 66210

July 22, 2002

Dear Doctor:

Thank you for purchasing ProHeart 6 (moxidectin), Fort Dodge Animal Health’s
innovative product for six-month protection against heartworm infection in
dogs. The purpose of this letter is to provide you with some new information
regarding a recently approved label indication for ProHeart 6, as well as a
review of the adverse events that have been reported for the product during its
introduction into the marketplace. This update on the performance of ProHeart 6
reflects our desire to share information that has been learned about the
product after its first year on the market.

ProHeart 6 was launched in June 2001 with an indication to prevent canine
heartworm disease caused by Dirofilaria immitis for six months, and to treat
existing larval and adult stages of the canine hookworm, Acylostoma caninum. As
a result of ongoing research on the product, the Center for Veterinary Medicine
(CVM) recently approved an additional label indication for ProHeart 6,
treatment of existing larval and adult stages of canine hookworm, Uncinaria
stenocephala. The addition of U. stenocephala to the ProHeart 6 label broadens
the protection provided against canine hookworm infection, and results in a
product that more closely meets the needs of practicing veterinarians.

Along with the new indication, a second label change will appear in the
“Adverse Reactions” section of the product labeling, and is based on the
reporting patterns received from the field. With over six million doses of
ProHeart 6 (moxidectin) sold during the first year, we have seen a number of
reported reactions that were not seen in pre-approval clinical studies. This is
typical in cases of a new product after introduction to a wide population base.
Through our work with CVM, a new label statement has been approved for ProHeart
6 describing our post-approval experience. The new statement being added is as
follows:

Post-Approval Experience: although not all adverse reactions are reported, the
following reactions are based on voluntary post-approval drug experience
reporting: anaphylaxis/toid reactions, depression/lethargy, urticaria, and
head/facial edema. As with anaphylaxis/toid reactions resulting from the use of
other injectable products, standard therapeutic intervention should be
initiated immediately.

Since introduction, we have received and tracked reports from practicing
veterinarians regarding adverse events subsequent to the clinical use of
Proheart 6. A review of these reports is presented below and includes events
observed when ProHeart 6 was administered alone, as well as those observed when
given with concurrent medications. The numbers presented are unfiltered, as
reported to CVM, which include observations subsequently determined to be
unrelated to product administration.

During the first twelve months of product use, 105 reports of site reactions
post administration (.0016% of doses sold into veterinary clinics) have been
received. These events are predominantly swelling, pain, and/or pruritos that
are observed post administration. The vast majority are self-limiting in
nature, though selected cases have been treated with anti-inflammatories, and
in some cases, antibiotics.

A total of 946 reports of allergic responses post administration (.015%) have
been received. As with vaccines, this category represents the most frequently
reported event. Most of these reactions are mild and have responded to standard
medical intervention. Some, however, have been more severe, including a small
percentage of anaphylaxis cases. The most frequently reported effects have been
vomiting and diarrhea, followed by angioedema and/or facial swelling, urticaria
and gastrointestinal symptoms. Other less common events include ataxia,
weakness, dyspnea, pale mucous membranes, lethargy and fever.

A total of 685 reports of illness post administration (.011%) have also been
received. This category encompasses a wide variety of reports that are received
in a broad timeframe (from one day to several months) post administration.
There is overlap with the allergic events where both allergy and additional
symptoms were recorded. The most frequently reported signs have been vomiting
and diarrhea at variable time frames post administration, seizures or other
neurological signs and lethargy. Other rare, but more serious reports, include
erythema multiforme in 3 cases and autoimmune hemolytic anemia in a low number
of patients, most of whom had received vaccines concurrently.

No common predisposing factors have been identified at this time. In rare
situations, death has been associated with some of the adverse reactions listed
above. While there reactions appear to be idiosyncratic, we want to bring these
to your attention so that you may take appropriate measures in the event you
encounter one. In the case of allergic reactions, prompt therapy using standard
medical intervention (e.g. antihistamine, corticosteroids and fluids as needed;
epinephrine as deemed appropriate on an individual case basis) has been found
to be curative in most instances.

As is the case when prescribing any medication, careful examination of the dog
prior to administration, consideration of appropriate laboratory tests in dogs
that may have chronic conditions, and advice to the owner to watch for signs of
drug intolerance is good medical practice. If a drug reaction or intolerance is
suspected, examine the patient, provide the necessary supportive therapy, and
contact Fort Dodge Animal Health Professional Services veterinarians at
1-800-533-8536.

As a manufacturer of novel innovative products, we feel it is important to
provide timely information regarding label changes and current information on
post-approval experiences. Millions of doses of ProHeart 6 (moxidectin) have
been used safely and effectively during its first year in the market, and we
trust that this has been your experience as well. We will continue to provide
you with any pertinent information regarding ProHeart 6.

Thank you for your attention regarding these important issues. You are
encouraged to contact one of our Professional Services veterinarians at the
number listed above if you have any additional questions or concerns.

Sincerely,

Stephen A. Connell, DVM
Director, Professional Services
Fort Dodge Animal Health

ProHeart 6 is generally well tolerated. Use with caution in sick, debilitated,
or underweight animals. A small percentage of dogs showed mild, transient
swelling or itching at the injection site. While rare, digestive, neurological
or hypersensitivity reactions may occur. Read the attached package insert for
more information. To obtain additional information including a copy of the
product labeling, visit the website at www.proheart6dvm.com or call
1-800-685-5656.

[KristaS]

As with most medications we give to our dogs or take ourselves, there is a risk with the pro heart injection. Yes, some dogs had adverse reactions, and unfortunately some of them died. But from over 6 MILLION pets who recieved the injection last year .0276% of those dogs had a reaction of some kind. I witnessed or gave the injection to maybe 500+ dogs (figuring we see ~ 35 pets per day and give the injection to at least one) and to date haven't had any reported reactions. Like I said, there are risks, but the benefit of knowing your pet is protected, not wondering if they threw it up in the yard or having to remember every month is reason enough for me to give this to Caly. Of course that is just my opinion.

[MARYDVM]

We have been using the Proheart injection for over a year now. In that time, had one reaction (vomiting, lethargy that lasted about 12 hours and resolved without treatment) in a dog that had also been vaccinated at the same time.

The primary advantage to the injection, is eliminating the chance of heartworm infection due to human error. There are a number of people who have had their dogs become infected with heartworms (including some on this forum) because they forgot to give one or more pills.

The primary disadvantage, is that the product remains in the body for 6 months, so if the dog has a reaction to it, it may be worse than with a medication that is passed out of the body within 24 hours of administration.

We carry the three types of heartworm prevention (ouch! inventory!) to give our clients a choice that fits their needs. I will go with the pills, or spot-on, rather than the injection, if the dog has ever had an allergic reaction (vaccination, drug, food) before. Or if the dog is elderly and has any health problems. Or if the dog is underweight for any reason. On the other hand, I particularly recommend the injection to clients with a history of missed appointments and lapses in preventative administration. Also very handy for clents who are moving, and have other things to worry about than where the dog's pills are. Our prices for pills and injection are identical.

[Debbie]

I was just at the vet and looked into this very issue. The vets in my office are discouraging use of the shot for the reasons that have been already been mentioned. I was particularly concerned about potential adverse reactions to a drug that would be in their system for 6 months.

Plus I would have had to make two trips - one for the heartworm test and then back again to get the shot once the test proved negative. That would have been a huge inconvenience since I have three dogs. No way do I want to have to four trips a year for heartworm prevention when one currently suffices.

Heartgard Plus protects against more intestinal parasites than the shot does, too.

My vet writes me a prescription so I can order the meds through the UPCO catalog which saves me quite a bit.

[KristaS]

What kind of heart worm test does your vet have? Our test only takes 6-7 minutes and we can administer the injection or get the pills together right after the test is negative.

[Debbie]

I don't know....but I know it's not immediate. I'll have to ask why they don't use one that is. I wonder if there is any problem with false readings?

[Birdie'sMom]

I was just at my vet on Monday and someone in the waiting room was asking about the shots. The vet said that they do not recommend it because it doesn't seem to work as well as the pills and that they only suggest it for people who have a hard time getting their dogs to take the pills.

[JeanT]

KristaS, Debbie- I was told by a vet that the "quick" test, reading a blood smear under the microscope in the office, will only let you know if the immature HW (microfilae?) is circulating in the bloodstream. The other test (which some vet offices have the equipment to test in-house) will test for mauture HW. The "quick" smear misses adult HW entirely. I think it's OK for dogs who have consistently been on preventative, though.

[KristaS]

The "quick" test I was refering to is a snap test where the blood is added to an anti coagulant and placed in the test which is snapped when the blood reaches a certain point in the testing device. The blood then reacts w/ the control indicator and if the dog has heart worm it will react w/ one or more of the three other possible indicators which would show up as blue dots. This probably doesn't make much sense, but I'm just trying to say our test isn't just a smear that could possibly be misread due to human errors, it is an actual test that just takes less time.