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No More Homeless Pets Forum
August 2, 2004 The Future of Spay/Neuter |
Dr. Julie Levy of the University of Florida and Dr. Brenda Griffin of Auburn University will answer your questions about the future of non-surgical contraception for animals, high-volume spay/neuter, juvenile spay/neuter, and more. You’ll learn everything you want to know about spay/neuter and the future strategies for ending pet overpopulation.
Introduction from Dr. Levy:
Vaccines that sterilize cats and dogs, long-acting contraceptive implants, less technical and cheaper pet contraception. Surgical spay and castration relegated to a historical footnote. Does it sound too good to be true? Right now it is, but research presented at a recent conference of the Alliance for Contraception of Cats and Dogs suggests that simpler solutions to pet overpopulation may brighten the future. Already, male dogs can be sterilized with a simple testicular injection of Neutersol without sedation.The ideal contraceptive for population control would be simple to administer in the field by lay technicians, prove effective in all ages and both sexes, inhibit sex hormone production as well as prevent conception, be efficacious in all animals treated, produce permanent sterilization with a single dose, and be safe for treated animals and the environment. Oh yes, and we want it to be very inexpensive as well. Not surprisingly, it is unlikely that a single product can achieve all these goals. This week's forum is your opportunity to tell scientists, the FDA, and the drug companies if you think progress in this area is important and what your priorities are.
Tune in this week to learn how close scientists are to developing reliable non-surgical contraception for dogs and cats. Share your thoughts on the role humane agencies should take in developing these new products. Can humane agencies support animal research if it helps to end pet overpopulation? Can animal welfare agencies help shape the way animal research is done and what becomes of the animals used in pharmaceutical research?
Although the future is bright, today we still rely on surgical sterilization as the most powerful weapon against overpopulation of cats and dogs. Veterinarians and humane agencies are sterilizing animals at younger and younger ages. "Neuter before adoption" has become a mantra to replace post-adoption sterilization contracts that are difficult and time-consuming to enforce. Spay/neuter clinics capable of sterilizing hundreds of animals in a day are opening throughout the country. And yet nagging questions remain: Is pediatric neutering safe? Do M*A*S*H-style clinics offer adequate monitoring and pain relief? Do we put individual animals at risk in our rush to end the overpopulation crisis?
Let's ask the hard questions this week. We'll explore the successes and the failures we've encountered and review the growing body of scientific literature on the sterilization of cats and dogs.
Questions
How Neutersol works
How far away are we from Neutersol type products for other animals?
What about the health benefits regular neutering provides? How does Neutersol address that?
Mortality rates in pediatric
Wet labs for vets on pediatrics and feral cats
How to order a feral cat video from Dr. Griffin
Infections at neuter site
What are standard accepted practices for spay/neuter surgeries?
Feral cats disappearing after surgery
Long-term studies on pediatric surgeries
Flank spays
Best anesthesia protocol
Oral vaccines
The future of spay/neuter
Young kittens being stressed after surgery at the shelter
How to talk to vets when experiencing high mortality rates
How Neutersol works
Question from a member:
I've heard a little bit about Neutersol but am not sure I fully understand how it works. I’m hoping you can explain it a bit more. Does it work in male cats and dogs? And does it work on juveniles or just adults? I've also heard that it doesn't work 100% of the time, which is a concern to me.Response from Julie Levy and Brenda Griffin:
Neutersol is the first permanent, non-surgical method of sterilization for companion animals. It is currently licensed for use in the U.S. for chemical castration of puppies 3-10 months of age. It is an intratesticular injection of a zinc compound (zinc gluconate neutralized by arginine), which results in sclerosis of the testes and permanent sterility. It is 99+% effective and very safe. The precise mechanism of action is unknown; the testicles atrophy over weeks to months following injection, resulting in a 70-90% reduction in testicular size in very young puppies and 50% in older dogs. (Atrophy may not be symmetrical). Sterility is immediate in young puppies, but may take up to 60 days in postpubescent males. In most cases, Neutersol can be administered without sedation. An insulin syringe is used to administer a single injection into each testicle and patient discomfort is minimal. Neutersol does not abolish testosterone production, and its effects on hormone dependent diseases and behaviors have not been established. However, studies have revealed a significant decrease in prostate size in Neutersol injected dogs versus controls. This product is a useful option in veterinary practice as well as animal shelters. The obvious advantage is that it eliminates the need for anesthesia and surgery and saves substantial time.Neutersol is also effective in cats, and although this is not an approved use at this time, I am confident it will be in time. Use in adult dogs will also be likely to follow.
The FDA requires an enormous amount of testing prior to approving products; and the testing has to be done in each species and each age group. That is why the initial approval was just for puppies 3-10 months of age - that is not to say it is not effective for others.
Neutersol is cause for celebration! It was more than 20 years in research and development, and millions of dollars. Yes, it takes millions to get product from the laboratory to the market place. That is the reality. So, it is much easier for human drugs to get approval - the $$$ is behind them. Now you know why your prescriptions cost so much!
We are very lucky to have Neutersol available for dogs!!! We need to support this product; then, pharmaceutical companies will be willing to invest the $$ to develop and market others!!! That will be a great day!!!
When that day comes, and it will, I hope I am there to help line the dogs and cats up and sterilize them humanely, safely, and quickly with non-surgical methods
How far away are we from Neutersol type products for other animals?
Question from Carrie:
How far away are we from a Neutersol-type product for adult animals, male kittens, and female babies?Response from Julie Levy and Brenda Griffin:
Researchers are closing in on non-surgical contraceptive strategies for cats and dogs of all ages and sexes. Already, Neutersol has been shown to be effective in male kittens and adult male dogs, although it is not yet licensed for these uses.Since Neutersol relies on injecting the product into the gonads (testicles), this strategy is unlikely to be suitable for use in females, who carry their gonads (ovaries) out of reach inside the abdomen.
Instead, use of long-acting implants or vaccines against reproductive hormones have been pursued for use in females. Luckily, many of these products are also effective in males.
Already, Suprelorin implants (deslorelin, a GnRH analog) are available in Australia and New Zealand. They are licensed for use in male dogs for 6 months contraception, but research shows they are effective in both male and female dogs and in female cats for one year or more. Fresh implants can be safely re-administered as needed.
Progestin implants have been shown to suppress hormone production and fertility in female cats and dogs for more than 2 years duration. The implants are easy to administer, similar to placing a microchip under the skin. These implants are still experimental and are not likely to reach the marketplace anytime soon.
Antifertility vaccines are also a hot topic of research. One of the most promising is a vaccine against GnRH, a hormone produced in the brain, which is required for production of testosterone and estrogen. These vaccines have been used successfully to control wildlife and food animals and early work is very promising in cats and dogs. Similar to progestin implants, a lot more research will be required before they are offered to the public.
Obviously, a big problem with all of these nonsurgical strategies is that contraception may not be permanent. Implants may need to be re-administered and vaccines may need to be boosted over time. Scientists are working hard to extend the duration of contraception following a single treatment. However, few alternatives are likely to be as predictable and permanent as surgical sterilization.
What about the health benefits regular neutering provides? How does Neutersol address that?
Question from Jude:
Although non-surgical methods seems like a great alternative for pet population control, I am concerned about the other argument for spay/neuter... reduction of cancer and other hormone related diseases. Is it simply a tradeoff, or are health benefits factored in?Response from Julie Levy and Brenda Griffin:
Contraceptive drugs and vaccines work by exerting a targeted pharmacological effect or prompting an immune response that inhibits or blocks some component of the animal's reproductive system, resulting in infertility. These products will greatly facilitate sterilization of dogs and cats since they will not require the commitments of technical expertise, equipment and time that surgical sterilization requires. The ideal contraceptive product would rapidly induce permanent sterilization, eliminate breeding behavior as well as fertility, provide the same health benefits as surgical sterilization, while requiring only a single dose.Furthermore, the ideal product would be effective in dogs and cats of both sexes and all ages, and be safe and easy to administer. Even if the ideal formulation cannot be produced, safe products that induce sterility in dogs or cats, male or female, will be valuable tools in the fight against pet overpopulation.
In terms of health benefits (such as eliminating the risks of certain cancers or reducing the risk of infection), we do not have all of the answers regarding that in the context of non-surgical products as yet. These answers will take time and will vary depending on the product. Surgical sterilization is really our gold standard at this time, but the value of sterility, with or without other benefits, is great. Removing hormonal stress and stress of pregnancy alone hold great promise in terms of benefiting pet health. Owners can always elect surgery at a later time if they so choose.
We are also assuming that surgery has the most "health benefits"; we do not know if that is true either. Allow me to play devil's advocate here, because, we really don't know... In fact, some argue that small amounts of sex hormones may be beneficial to animal health.
To me, two things are clear: the products must be safe (rule number one is to do no harm) and effective (they must sterilize the pets). If they do that, I am very, very pleased. One size does not have to fit all, and we need more tools in our belt in the fight against the "disease" of homelessness and surplus pets. That has the most health risks of anything I know.
With Neutersol, for example, a great product!!! Fits my rule of 2: it is very safe and it works!!!! But, testosterone production is significantly curbed, but not eliminated (surgery eliminates it). We don't have all the answers yet as to what that means health-wise. However, we do know that prostate size is much smaller in Neutersol dogs compared with intact males... That is a very good sign, and suggests that health benefits may be similar in regards to the incidence of prostate disease among Neutersol dogs and surgically neutered dogs. I am very hopeful... we will see.
To me, neutering more dogs and cats safely and effectively is no trade off!
Mortality rates in pediatric
Question from Ann:
I am a big supporter of early age spay/neuter and our group does 2lbs/2months. However, there is another group in town that won't do early age, because they have seen 5 kittens die after surgery and feel the risks are too high. I have tried to explain that this could happen in adult surgeries too. It could be an unknown condition or some other reason besides the early age surgery, but they are adamant that they will not do below 5 months because of this. I have offered countless studies but they say that their vet agrees below 5 months is too young and can cause problems. When you are arguing against this type of emotion and personal experience they had, what can you do to help convince them to try it again and give it more of a chance?Response from Brenda Griffin:
Wow, now there's a question! I am hoping Dr. Levy will have some answers for you here...I have to say, that first off, you can't convince everyone. No such thing as 100%, and that's okay. Just go about convincing everyone else... and in the end, the others will likely follow. Try some of the video resources I described in my answer to the last question; those would be great to give them to watch.
Second, it will be very hard for them to "go against" the advice of their own vet. Difficult situation. Maybe the vet will attend a CE on pediatric spay/neuter sometime.
Keep up your good work... and let's see what other advice Dr. Levy can offer.
Response from Julie Levy:
Death after surgery should be a rare event, regardless of the age at which it was done. It's hard to say much without knowing more. Did the kittens die at the same time or were all the deaths unrelated? A cluster would suggest something unusual, such as an outbreak of panleukopenia, a medication error, or a high-risk litter. Intermittent deaths might suggest a more systematic problem such as inappropriate anesthetic protocols or monitoring.To put surgical death rates in perspective, the rate of death in our feral cat sterilization program is 0.35% (3.5 deaths per thousand surgeries). We sterilize cats as young as 12 weeks in that program. In our foster program, we've sterilized more than 2000 kittens as young as 7 weeks, and I can count the deaths on one hand.
There is no question that kittens and puppies can be safely sterilized at very young ages. There are differences in how we handle them compared to adults, such as short fasting times, attention to preserving body temperature, and rapid recovery times. I am a big believer that most animals that are healthy enough for adoption should be healthy enough to be sterilized. "Neuter-Before-Adoption" takes the guesswork out of sterilization contracts and guarantees that we won't unwittingly contribute to the problem we are trying to solve.
With this in mind, it is also important that everyone work within his/her comfort zone. Veterinarians who have had a bad experience might prefer to restrict the animals on which they perform surgery. In doing this, they are looking after the welfare of the animals, which should always be the primary concern.
Change does not happen in a day. Some groups have embraced early neutering with gusto and others have been more cautious. Since everyone is working toward the common goal of ending overpopulation in their own way, it's more important to focus on what we all agree on than on the few differences we have.
Wet labs for vets on pediatrics and feral cats
Question from Sandy:
How useful do you think wet labs are in helping convince vets to try pediatric spay/neuter and also on feral cats? If you think it is useful, how do you go about setting one up?Response from Brenda Griffin:
Hi, great question!!!!!I think wet labs are very helpful for teaching pediatric spay/neuter. Having the opportunity to see one and do one in that setting can really jump start the learning curve and be a real confidence builder. I find that vets are often "scared" to perform surgery on very young/small patients. Once they see it is easy and okay, they are ready to go.
I teach a pediatric Spay/neuter wet lab at the Annual Veterinary Conference hosted each year by Auburn University College of Vet Med. I have had vet's tell me how surprised they were by how easy it was. One very skeptical and nervous vet emailed me a few months after the lab to tell me she had since spay/neutered almost 800 puppies and kittens since participating in the lab. I almost fell out of my chair. There's a testimonial!
After attending the NMHP Symposium in California, one attendee who heard me singing the praises of wet labs set up several in her area hosted by the Animal Match Rescue Team (AMRT). Their web site is www.amrt.net. They may be able to give you ideas on how to organize a lab based on their experience.
For feral cats, I would suggest a video telling them all they need to know. I got weary of all the calls I received where vets basically were requesting a feral cat how-to manual. Well, a picture is worth a thousand words, so we made a video. And we sell it dirt cheap; we just want to get the word out. See below.
"Working with Feral Cats in Practice"
an instructional video by
Whitney Lemarr (Class of 2004) and Dr. Brenda Griffin,
College of Veterinary Medicine, Auburn University
Copy write 2003, Biomedical communications, AU
(Details and ordering instructions below)
Also of interest to you may be these resources for veterinarians:
Video: "The Case for Early Neutering"
Available from the American Humane Association, phone #303-792-9900
Video: "Early Age Neutering: A Practical Guide for Veterinarians"
Available from UC Davis/AVAR, phone #530-759-8106
Go for it!!!
Response from Julie Levy:
Nothing beats first-hand experience. Trying out a scary new procedure under the watchful eye of a trusted experienced colleague is a real confidence builder.This can be done in several ways. Formal wet-labs are nice because they are organized specifically for teaching. Educational materials, lectures, demonstrations, and practice can be organized to provide a thorough review and step-by-step practice.
The limitations of formal wet-labs are the cost and effort that needs to go into them, as well as the limited times and places they can be offered. One should also be cautious about running afoul of regulations that are designed to protect animals used for teaching. You may know that your animals are well cared for, but that does not absolve you of the need to comply with state and federal regulations (which are constantly changing). The last thing you want is to be cited for an animal welfare violation because your paperwork was not in order.
If a formal wet-lab can't be organized, an alternative is to invite your veterinarians to observe and perform surgeries somewhere they are already being done. This has the advantage of providing a "real world" context, and they can observe how the supporting environment is organized. Spay/neuter clinics and shelters are great places to see quality pediatric surgery being performed and to witness the quick recoveries these patients have compared to adults. Large-scale feral cat neutering clinics operate all over the country and provide examples for how the cats can be safely handled, methods for efficiently sterilizing large numbers of cats, and how to incorporate volunteers into the process.
The benefits of visiting other facilities is that vets can get their feet wet without putting their practice and private patients at risk. In my experience, once they've done it a few times, the fears evaporate and they tend to loosen up on their own turf as well. Anyone who has spayed a puppy will curse the necessity of performing surgery on a 100-pound obese in-heat female dog in the future.
How to order a feral cat video from Dr. Griffin
To obtain a video, please send a check for $10 for each video (specify which/how many), payable to Auburn University Foundation, to Dr. Brenda Griffin, Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849.
"Working with Feral Cats in Practice"
an instructional video by
Whitney Lemarr (Class of 2004) and Dr. Brenda Griffin,
College of Veterinary Medicine, Auburn University
Copy write 2003, Biomedical communications, AU
The purpose of this video is to provide veterinary practitioners with the information and techniques required to assist clients with management of feral cats using the method known as trap-neuter-return (TNR).
This video includes:
1. An overview of feline overpopulation and methods of control, including TNR
2. Detailed descriptions of feral cat trapping and holding procedures, and precise step-by-step instructions on how to anesthetize and treat feral cats in veterinary practice
3. An overview of how to establish and run a large scale TNR operation
The video describes in detail issues and techniques involved in working with feral cats. References for additional sources of information and equipment are included.
"Promoting Pet Health and the Human-Animal Bond Through Spay/Neuter Counseling"
an educational video by
Kim Smith (Class of 2004) and Dr. Brenda Griffin,
College of Veterinary Medicine, Auburn University
Copy write 2003, Biomedical communications, AU
This video and accompanying printed materials are designed to help veterinary and animal care professionals as they prepare to counsel clients about this essential topic. The video consists of general background and medical information on sterilization followed by realistic scenarios that are frequently encountered in practice. The video illustrates diplomatic and medically sound counseling techniques that inform and reassure the client as they elect to spay or neuter their pet.
Scenario I: Risky Business
Miss Hammond is concerned the surgery will be too traumatic for her beloved pet and really doesn’t see the need to spay.
Scenario II: Cut Off His What?!
Mr. Heath fears neutering will change his pet in some way.
Scenario III: How Much is the Doggie in the Window?
Mrs. Smith is ready to make some money by breeding her purebred dog.
Scenario IV: Just One Litter
Miss Lowe feels it is best for her cat to have a litter of kittens first. She would also like to teach her children about the Miracle of Birth.
Scenario V: Pound Puppies
Mr. Allen adopted his dog from the shelter and doesn’t see the need for the spay contract.
Scene VI: The Cat Lady
Miss Green is feeding some feral cats and needs some advice from her veterinarian.
Infections at neuter site
Question from a member:
We get puppies from area shelters that have done Neutersol and are seeing a lot of infections at the neuter site. It makes me wary of supporting Neutersol seeing this many problems in just our small experience! What do you attribute this to? Are they just not doing the injection properly or is there something else?Response from Brenda Griffin:
First, I would ask if the injection technique is correct. It is extremely important to follow the instructions very precisely. I have injected many pets and have seen no problems with the appropriate technique, nor were they reported in the field studies. The experience of others may be different than mine, but from all I have seen and experienced, the key to preventing and minimizing problems is to use the appropriate technique.Be sure to use an insulin syringe. The needle is tiny, almost as fine as a strand of hair. If you use a bigger needle, you are likely to have problems. If the Neutersol leaks out of the injection sight in the testicle into the scrotum, it can be very irritating!!!!!
Also, be sure the pup is calm during injection and is kept quiet for a couple of days afterward. Be sure the needle is positioned just as it is written in the instructions, and do not inject too fast. Also, do not shave or scrub the area before injecting; scrotal skin is very sensitive and may react just to that.
Also, keep in mind that with surgery, well, that is not perfect either. You can end up with infection, hematomas (blood filled scrotum), suture reaction, dog licking the incision open.... etc. etc.
We need to do our best to minimize problems, but as with anything, there are bound to be a few minors ones that crop up here and there. A severe reaction in my experience is very rare indeed with Neutersol.
Response from Julie Levy:
It would be helpful to know what percentage of puppies is having reactions. Maybe there have been just a few out of many that were treated, but they made a big impression because it is a new technique. The more people talk about it, the bigger the problem seems.Of course, all adverse reactions to drugs should be reported to the manufacturer and to the FDA. In this case, they should also be reported to the shelter vets that are using it. Have these cases been reported? If so, how were they resolved? As a profession, veterinarians tend to get caught up with their hectic schedules and can forget about the importance of reporting. This is especially crucial when we are using new products. On the other hand, we need to be careful about becoming part of a rumor mill if we don't have any first-hand experience ourselves. So many false rumors circulate and grow on the Internet
nowadays that there are now multiple web sites devoted to debunking them.
With those cautions in mind, I agree with Dr. Griffin that if reactions are occurring at a high rate then injection technique should be the first concern. It is also important that puppies be kept quiet for a few days after treatment and that they wear an E-collar if they have a tendency to chew or lick the injection site.
You are right to be concerned. My experience with the Neutersol group is that they are very responsive to questions. I recommend that you document the problem and then call up the company to discuss what you have observed. If there is a question about the use of Neutersol, maybe they can send a representative to review the way the drug is being used.
What are standard accepted practices for spay/neuter surgeries?
Question from Erica:
We do a lot of feral cats and take them to a variety of veterinarians. It seems that many do things quite differently. Some use anesthesia protocols where the cats are very groggy afterwards, some use the same gloves to neuter multiple cats, and others don't use masks or gloves saying that it is completely sterile without doing so.We have certain things we would prefer but don't know how to tell veterinarians this without their taking offense. We are afraid they won't do surgery for us then but are uncomfortable with some of the things like using the same pair of gloves on multiple neuters.
How do you know what is the standard accepted practice for spay/neuter policies and procedures and how do you approach veterinarians to talk about these if you are a lay person?
Response from Julie Levy:
It is true that vets will have lots of ways to do things that lead to the same result in the end: a safely sterilized cat. A lot of the preferences have to do with the resources at hand, including the cost of materials, the skill of the staff, the number of personnel, the space in the facility. Others are more related to personal experiences (good and bad) and what was available at the time they were trained. Once something works well it is not always a good idea to experiment with new ideas.On the other hand, there are also minimum standards of care that should be met for all animals, even the homeless ones. The problem is, we don't all agree on where to draw the line.
For example, the veterinary profession is becoming more conscious of post-operative pain in animals, and progressive practices provide high quality analgesia for all of their surgery patients as part of the package. Other practices leave it up to the owner to decide if they are willing to pay for pain relief. Still others (including many humane agencies) only provide pain relief in exceptional circumstances. Issues of cost, practicality, safety, and tradition all come into play in these decisions.
My specialty in infectious diseases, and I place a high priority on using practices that prevent the spread of fatal diseases such as FeLV and FIV. For example, I feel strongly that we should use "universal precautions" to prevent blood and other body fluid contamination between patients. That means no sharing of needles or instruments or gloves, sterilizing tattoo equipment between patients (practically impossible), not reusing suture tails, decontaminating endotracheal tubes, and avoiding cold sterilization of instruments.
Other vets feel that compromises to save resources for "herd health" mass sterilization are ok. I think everyone has to find there own comfort level and each group needs to know what their own standards are when they negotiate with vets. I think it is a good idea to have a formal meeting with new vets before presenting any cats for surgery to review the protocols and make sure everyone agrees.
Finally, each state has a veterinary practice act that defines many standards of care. All private and shelter clinics have to meet these standards, regardless of which animals they practice on.
Feral cats disappearing after surgery
Question from Jen:
We currently do a high volume MASH clinic for feral cats. We feel we are working very hard to uphold quality and sterile procedures. Recently though we are finding that many of the cats we return back to caretakers are not being seen - either at all or infrequently. Some of our volunteers are now worried that maybe we are doing something wrong and that we shouldn't be doing high volume surgeries. I am hoping that it is because they just need to get away because of the stress of the situation or because now they are fixed and are less likely to roam or they are friendly and getting picked up by people to adopt them; but now I am worried too. How can we make sure we are doing right by the cats and still maintaining our surgeries to get the numbers down?Response from Brenda Griffin:
I am sure Dr. Levy will have a lot to offer here, but here is my experience...We always warn caretakers that bring cats to our clinic that the cats may lay low for days or even weeks following spay/neuter. We try to inform them of this, without alarming them. We also explain that in the vast majority of instances, the cats return to their usual behavior and routines in time, and we emphasize how improved their welfare will be. They will be cats, we tell them... and, they will try to make you fell "guilty" for trapping them and bringing them in, but ultimately, they will be much healthier for it, and it is the right thing to do. When the alternative is multiple litters of kitten, a high kitten mortality rate, fighting, territorial aggression/marking, and continued hormonal stress and welfare issues for the cats, plus nuisance complaints, and the moral issues of allowing uncontrolled reproduction, the reality that it is the best thing sinks in. Stick to the facts. Get them to think logically, be patient. They love the cats and it may be hard, but as you know, it is the right thing to do.
Check out our program at www.auburn.edu/catnap
By the way, Dr. Levy's is the largest and the original veterinary college based program. We are just copycats!
Response from Julie Levy:
Some cats are so freaked out by the whole trapping and surgery procedure that they move to a new location once they are released. Often, these cats will reappears days or weeks later.If this happens a lot, I would investigate further. Visit the colony sites and talk to the caretakers about their procedures. Could the management of the colony be improved to make the area more attractive to the cats?
There is also a concern that cats who disappear have become ill or had surgical complications. This is the worse possible outcome and the one that we fear the most.
If the disappearance of cats is a recent development, this should prompt a thorough search for any changes in procedures that might have triggered it. A review of clinic procedures and perhaps a visit from an outside consult (unbiased observer) would be helpful.
Long-term studies on pediatric surgeries
Question from Crystal:
If I had a dollar for every person who said, "Gee, I didn't know my five-or-six-month-old cat could go into heat and have kittens!" I'd be rich enough to start my own spay/neuter clinic! For this and many other reasons, I'm inclined to believe that early-age spay/neuter is the way to go for shelters and rescues.My question is... have any studies been done on the long-term effects of early-age spay/neuter? The kittens I have seen who have been spayed or neutered at a young age all seem to bounce back beautifully and are romping and playing the next day. But are there long-term negative effects once they grow up?
Thank you for your time. I believe that spay/neuter is the only way we are ever going to make a difference in pet overpopulation.
Response from Brenda Griffin:
Although virtually all animal shelters require adopted pets to be sterilized, the compliance rate of owners according to the American Humane Association is only approximately 50-60% on a national basis, despite implementation of spay/neuter contracts, coupons, other incentives and time-consuming follow-up. For these reasons, the American Veterinary Medical Association advises that all pets be neutered before adoption, including puppies and kittens as young as 8 weeks of age.The ideal age to spay/neuter dogs and cats is unknown. Currently, the most common age or the "traditional age" for recommending spaying/neutering is 6 months. This recommendation, however, is not based on research indicating that this is the ideal age to perform these procedures, but was probably chosen because anesthetic and surgical techniques were less advanced at the time and surgical success was more likely in a larger patient.
Approximately 30 years ago, humane organizations began sterilizing young puppies and kittens. Understandably, many veterinarians expressed concerns and questions regarding the short- and long-term safety of sterilizing pediatric patients. In response to these concerns, numerous controlled prospective studies and retrospective cohort studies have been performed to verify the safety of early age spay/neuter. Based on these studies, we can now conclude that sterilizing young puppies and kittens is a medically sound practice, and is not associated with any serious medical or behavioral risks. In addition, early age spay/neuter offers many advantages including well-established, safe anesthetic and surgical techniques, shorter surgical and recovery times, and avoidance of the stresses and costs associated with spaying while in heat, pregnant or with pyometra.
There are also numerous long-term health benefits including virtual elimination of the risk of mammary and testicular tumors. Finally, in addition to benefiting the individual patient, early age spay/neuter helps veterinarians to fight the single largest killer of dogs and cats: overpopulation and euthanasia of unwanted, homeless pets.
Reasons to Perform Early Age S/N:
- No substantial medical reasons to wait
- Guaranteed compliance
- No "whoops litters" (pregnancies at <6 mos)
Controlled studies have been done looking at everything from body composition to growth rates, immune function, urinary tract disorders, behavior, and long term effects. So many studies have been done; it would take me several pages to describe them all to you. No significant differences have been found in cats spayed or neutered at an early age versus a traditional age. Most recently, a retrospective study done at Cornell by Spain and Scarlett showed that no serious long-term medical or behavioral risks are associated with early age sterilization.
In cats, there is no increase whatsoever in the risk of urinary tract disease, and development (including size and function) of the urethra is normal in neutered cats compared to intact controls, regardless of age at neuter. For cats, this has always seemed to be the biggest concern among practitioners - the thought that if spayed/neutered too young, the urinary tract would not develop correctly. It is clear from numerous studies that it develops just fine! The one thing I would say is that for female puppies, there is a higher risk of incontinence later in life if spayed before 12 weeks of age (Spain and Scarlett showed that). Bear in mind, that incontinence in female dogs is easily and inexpensively treated, and in the study was not associated with relinquishment, which was notable to me. Finally, bear in mind all health benefits those young pups got from being spayed that young, no mammary cancer, no uterine infection... all good things. This increased risk of incontinence does NOT occur in cats.
See below for a handout I like to use to explain all the medical benefits of S/N
SPAYING/NEUTERING
Why it's medically best for your pet
FOR YOUR FEMALE DOG OR CAT:
Spayed females are often healthier than those who are not spayed. Intact females commonly develop problems such as:
Breast cancer
Ovarian or Uterine Cancer
Uterine Infections
Vaginal Prolapse
These problems can be life threatening.
- Breast cancer occurs more frequently in dogs and cats than in humans.
- Mammary tumors are the most common tumors in female dogs and nearly 50% are malignant. A dog spayed before she has had her first heat cycle has virtually NO RISK of developing breast cancer. Her risk dramatically increases if she is spayed after experiencing heat cycles.
- In cats, mammary tumors are the 3rd most common type of cancer and nearly 90% are malignant. They have usually spread to other parts of the body by the time they are diagnosed. A cat spayed before she is 2 years of age is 7 TIMES LESS likely to develop mammary tumors.
FOR YOUR MALE DOG OF CAT:
Intact males are at risk to develop serious problems such as:
Testicular Cancer
Prostate Disease
Hernias
Perianal Tumors
Flank spays
Question from Liza:
What are the advantages and disadvantages of the flank spay (in cats)?Response from Julie Levy:
Great question Liza.Let me start by saying that the benefits of one approach over the other are not so great that they exceed other issues, such as the comfort zone of the surgeon.
The flank approach places the incision on the flank of the cat about halfway down the side from the spine. The left side is more commonly used than the right, but it can be done on either side. The midline incision runs on the middle of the abdomen. The full uterus and ovaries can be removed from either approach. Out of tradition, the flank approach is taught in the UK, whereas the midline approach is taught in the US.
Benefits of the flank approach:
- It's a little faster (at least for me)
- An incisional complication will not lead to evisceration
- It is out of the way of mammary glands in lactating cats
- Caretakers can monitor the incision without handling the cat
- Good for cats with pyoderma of the ventral abdominal skin
Disadvantages of the flank approach are mainly due to the inability to perform a thorough exploratory of the abdomen.
- Harder to confirm that a cat has been previously spayed
- Nearly impossible to retrieve a dropped vessel, ovary, or uterus
- Unable to figure out those cats with weird anatomy that are missing parts of their reproductive tracts.
For feral cats, I prefer the flank approach. It's just a little easier for me. I don't like to spay juveniles this way because their tract is a little tighter and tears easier. It's harder to get the whole thing out via the flank in kittens. I also don't like to do pregnant cats via the flank, mostly because it leaves a large visible scar. However, I have ended up spaying both pregnant cats and cats with pyometra this way.
For pet cats, I prefer the midline approach. Sometimes hair on the incision line grows back kinky or another color or the scar is visible at the surgery site. There are no cosmetic problems with a midline approach. I don't think feral cats are as vain as pet cats.
Response from Brenda Griffin:
Some surgeons prefer a flank approach rather than the traditional ventral midline incision. The flank approach allows caretakers to monitor a cat's incision from a distance and helps prevent evisceration should dehiscence of the surgical wound occur. A video entitled "Left Lateral Flank Spay" is available from the National Humane Education Society by calling 304-724-6558. The flank approach is not generally recommended for pregnant queens, but is desirable for lactating queens. I think Dr. Levy has covered this question very thoroughly, and I agree... as long as the surgeon is experienced, the cats should do well with either approach. I usually do the ventral mid-line approach myself.Can you believe that Dr. Levy taught me to spay a cat when I was a senior student, which is when she was an intern (her first year out of vet school) at the MSPCA! Years later, I learned the flank approach at one her Operation Catnip clinics!
Best anesthesia protocol
Question from Cathy:
Can each of you detail your anesthesia and other drug protocols for high-volume (50 or more) spay days? What kind/how do you give pain management drugs? What about drugs to wake the cats up faster after surgery? What is your reasoning for the particular protocol(s) you recommend? Have you made any changes to your protocols since inception of your programs, and why? Is there anything in particular you would NOT recommend or would warn against? Thank you.Response from Julie Levy:
Our situation is pretty specialized. We only sterilize feral cats in large-scale clinics once a month.The ideal anesthetic for us would be cheap, easy to administer to cats in their traps, allow a dosing scheme that does not require weighing the cats, have a rapid induction with minimal vomiting, provide predictable surgical anesthesia without the need for supplemental drugs, support the physiologic status of the cats, be rapidly reversible, provide potent and durable analgesia, and be completely safe for the cats and personnel. It would also be nice if the drugs were not controlled by the DEA.
Such an anesthetic has not yet been discovered, so we make lots of compromises. We use "TKX." To make this cocktail, take one vial of dry Telazol and add 4 ml of ketamine (100 mg/ml) and 1 ml of large animal xylazine (100 mg/ml). Regular adult cats receive 0.25 ml injected "intracat." Very large toms and advanced pregnant cats get 0.3 ml. Kittens get 0.1-0.15 ml. This is an off-label use of the drugs and no studies have been performed on the stability of the mixture. It costs about $1.70/cat.
TKX is very predictable with a low mortality rate (3.5 deaths/1000 cats). Cats are recumbent within 5 minutes of injection and usually remain in a surgical plane of anesthesia long enough to complete the surgery. We have isoflurane machines that are used to supplement cats by mask if they are too light for surgery. At the end of surgery, an equal amount of yohimbine is given IV to speed recovery. Some groups reduce the recovery time by cutting back on the TKX dose.
Although mortality is very low, we have also documented low blood pressure and low oxygen levels in more cats than we are comfortable with. We also have slow recoveries (partly due to hypothermia that develops), which forces us to release cats to their caretakers before they are fully recovered. I am certain that the analgesia provided by TKX, especially after reversal, is not optimal.
For these reasons, we are experimenting with other drug combinations to improve the safety and pain control of our anesthetic procedures. Currently, we are studying a cocktail of medetomidine, ketamine, buprenorphine. Stay tuned!
Here's an abstract of a paper we wrote about our experience with TKX.
J Am Vet Med Assoc. 2002 May 15;220(10):1491-5.
Use of the anesthetic combination of tiletamine, zolazepam, ketamine, and xylazine for neutering feral cats.
Williams LS, Levy JK, Robertson SA, Cistola AM, Centonze LA.
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
OBJECTIVE: To evaluate the use of the anesthetic combination tiletamine, zolazepam, ketamine, and xylazine (TKX) for anesthesia of feral cats at large-scale neutering clinics.
DESIGN: Original study. ANIMALS: 7,502 feral cats.
PROCEDURE: Cats were trapped by their caretakers for a feral cat neutering program from July 1996 to August 2000. The anesthetic combination TKX was injected IM into cats while they remained in their traps. Each milliliter of TKX contained 50 mg of tiletamine, 50 mg of zolazepam, 80 mg of ketamine, and 20 mg of xylazine. Females were spayed by veterinarians, whereas males were castrated by veterinarians or veterinary students. Yohimbine (0.5 mg, IV) was administered at the end of the procedure. Logs were kept of the individual drug doses, signalment of the cats, and any complications encountered. These data were analyzed retrospectively (1996 to 1999) and prospectively (2000). RESULTS: Of the 5,766 cats for which dosing records were complete, 4,584 (79.5%) received a single dose of TKX. The mean initial dose of TKX was 0.24 +/- 0.04 ml/cat, and the total mean dose of TKX was 0.27 +/- 0.09 ml. Overall mortality rate was 0.35% (26/7,502) cats, and the death rate attributable solely to potential anesthetic deaths was 0.23% (17/7,502) cats.
CONCLUSIONS AND CLINICAL RELEVANCE: The use of TKX for large-scale feral cat neutering clinics has several benefits. The TKX combination is inexpensive, provides predictable results, can be administered quickly and easily in a small volume, and is associated with a low mortality rate in feral cats.
Response from Brenda Griffin:
Dr. Levy's response and mine are virtually the same. We sterilize 60 - 100 cats in a morning and use TKX. We advise that cats be held in their traps overnight by their caretakers prior to release. Some cats do have more prolonged recoveries than others with this anesthetic cocktail.TKX is prepared by reconstituting one vile of Telazol (500mg) with 4ml of Ketamine (100mg/ml) and 1ml Xylazine (100mg/ml). It should be noted that this is the concentration of Xylazine marketed for use in large animals and not the 20mg/ml small animal product. The dosage of TKX is 0.25ml per cat IM. A maximum dosage of 0.3ml per cat should not be exceeded. For very small kittens a slightly smaller dose of 0.15-0.2ml is used. This provides 20-30 minutes or more of anesthetic time. If additional time is required, an inhalent anesthetic such as Isoflurane should be used. Reversal (if needed) is achieved with Yohimbine (2mg/ml; 0.5ml per cat IM or IV). An additional dose of Yohimbine may be given after 30 minutes if results are inadequate.
Alternatively, a cocktail known as KDT) may be used. This is prepared by adding 10 ml vial of Ketamine (100 mg/ml), 1.0 ml medetomidine (Domitor, 1 mg/ml), and 3 ml butorphanol (Torbugesic, 10 mg/ml) to an empty 15 ml vial. Alternatively, the cocktail could be mixed in a 10 ml vial of Ketamine by first removing and discarding 1 ml of Ketamine to allow adequate space in the vial to add 0.9 ml medetomidine and 2.7 ml butorphanol. Dosage is 0.6 ml per average cat (slightly more for large cats and slightly less for small cats). Reversal is accomplished with antipamasol (Antisedan 5 mg/ml) at a dosage of 0.2 ml IM per cat. This does not buy you as much anesthetic time in my experience as TKX, and spays require supplemental isoflurane. Recovery time, however, is usually quicker. If I am working alone (not in the high volume clinic) doing a few cats myself, I use this.
Nothing is perfect, but we do the best we can to keep it safe, cost-effective, and balanced anesthesia, with good pain control.
Oral vaccines
Question from Marge:
I've read about injections for male puppies and implants for contraceptive purposes. What about oral vaccines for female cats? Is there anything available for female cats and where can I find it?I read about promising results from the late 90's for an oral vaccine using salmonella to cause production of antigens, which prevent contraception in cats. The article said this should be available in 2-4 years - what happened?
I'm feeding a feral cat colony and need some alternatives to surgical spay/neuter. Several weeks ago, I lost a female within 24 hours after spay surgery (no obvious underlying cause) and am looking for a better way - preferably through some oral dosing. What about ovaban?
Response from Julie Levy:
Wouldn't it be great if we could sterilize feral cats with oral baits similar to those that are used to immunize wildlife against rabies!There are two hurdles to overcome. The first is probably easier: to develop an oral vaccine that would sterilize cats. This is what you've heard about in the past, but so far efforts to develop such a vaccine have been unsuccessful.
The second hurdle is more of a challenge. That is how to assure that non-target animals, the food chain, and humans are not inadvertently contaminated by exposure to the vaccine in the environment. The vaccines currently under testing are not specific for a single species. Even delivery systems that target cats would be unlikely to affect just domestic cats and not wild felid species. In the case of rabies, it's not a big deal if the wrong animal is immunized by an oral bait. However, it would be a tragedy if endangered wildlife fell prey to untargeted sterilization.
Ovaban and other drugs have been used in the past for controlling feral cats but are not a practical solution for most situations. These drugs are associated with a fairly high rate of adverse side effects and have to be given to cats in a controlled and continuous basis - not an easy thing to do in a feral cat colony.
The future of spay/neuter
Question from Mary:
I'd be interested to see where you think spay/neuter will be in 20-30 years? Do you think we will always have surgical, or do you think it will be completely oral or nonsurgical? Will non-veterinarians ever be licensed to do it if it is nonsurgical, and how will that affect the veterinary profession?Response from Julie Levy:
Great question!I think the answers will be different for different situations. For pets that are under more constant control, there will probably be more surgical and nonsurgical options. Some treatments might need to be administered repeatedly whereas others, like surgery, would be used once only.
I don't see any movement toward extending surgery rights on dogs and cats to non-vets, but if you think about it, trained and untrained technicians already legally sterilize food animals and ferrets. I don't see why non-vets would be prohibited from administering nonsurgical treatments (like other medical treatments), as long as it was under the direction of a vet.
What we do regarding sterilization in the future may also be affected by society. Already, there are some European countries that do not have dog overpopulation problems because owners are so responsible. Some of these countries have banned elective sterilization as an unnecessary invasive procedure. Although framing the responsibility to "not neuter" in the context of an animal welfare issue seems so foreign to us, it does make an interesting discussion point.
Response from Brenda Griffin:
The future of spay/neuter... I dream of it... I do see a day when we have a variety of options for sterilizing pets, and these tools will help us to sterilize many more dogs and cats. I think it will be different strokes for different folks; one size will not fit all.And, yes, I think there will be methods that can be prescribed by vets (and not solely administered or performed by them). There is already precedent for that: Neutersol, the first non-surgical sterilant, is licensed to be given by OR on the order of a veterinarian, so it can be given by non-licensed individuals.
You know, pet overpopulation is a societal problem. In Sweden, Norway and Germany, where the unquestioned societal norm for pet owners is to control their pets' reproduction, pet overpopulation does not exist. They do not spay/neuter there; they control their pets, they just do, period. We have to shape our society - see the cat, feed the cat, sterilize the cat. That is my dream.
Thanks for all of the wonderful questions this week.
I invite you to visit our newly launched shelter medicine website: www.aumaddiessheltermedicine.org
Keep up all of your good work for the animals. Each and everyone matters. And remember, collaboration is key to solving the problem.
Young kittens being stressed after surgery at the shelter
Question from Lea:
Our organization does some work with a large municipal shelter that does on-site spay/neuter before adoption. We are very thankful of that.We have been concerned lately about their protocols with a new staff veterinarian. They previously did not do surgery unless the juveniles were at least 2 pounds and at least close to 8 weeks. There is a small yet effective foster program for the ones that are pulled but are too young, and most are willing to keep them as long as needed.
However, we are seeing ones done that are 5 and 6 weeks and as small as 1.5 pounds or even just under that. I know there are vets that have been doing pediatric s/n for years, and are doing very young and small like that, but this vet is not only new to pediatric s/n, but new, period.
The little ones get adopted so quickly, and this shelter, being very large, municipal, short-staffed, and very low on volunteers, doesn't have time to do counseling or follow-up. But many of those that are around for a couple of days or so, look like they aren't recovering well. That usually gets attributed to the upper respiratory that perpetually goes around in shelters, and that may be so. But we are worried that at that age, their immune systems just can't handle it and wonder if this is serious enough to be addressed. We don't want to offend the vet or the rest of the staff, but we are concerned.
Response from Julie Levy:
I've sterilized very small kittens without problems, although I don't see the benefit of doing them much younger than the age of adoption. On a technical level, the anesthesia and surgery are no problem. Is this shelter adopting out 5 week-old-kittens?The bigger issue is whether it is a problem to add an additional stressor at the time when kittens are undergoing weaning stress and may be in the gap between good maternal immunity and their own acquired immunity. This can be a difficult time for juveniles, and surgery can be another drain. Delaying the surgery to 7 or 8 weeks may help reduce that drain, but it does not remove it entirely.
In general, I believe that time in the shelter should be minimized due to the risk of infectious diseases such as upper respiratory infection. The shelter may be trying to do this by neutering the juveniles young and adopting them out quickly. An alternative is to put them in foster homes until they are older, then bring them back for sterilization and adoption. During kitten season, it may not be possible to provide enough foster space for all of the underage kittens, and it can be complicated to manage such a system.
I wonder how many people reading this are wishing they had these problems: vets wanting to sterilize cats and dogs very young and the shelter adopting out animals very quickly! So many groups can't find vets to sterilize before 6 months and so many shelters are nothing more than a holding facility for condemned animals. I think I'd count your blessings. How about arranging a big "thank you" party for the shelter for being so progressive? After you've made a public display about how much you support the shelter, you might arrange a private meeting about how you'd like to help improve any problem areas.
How to talk to vets when experiencing high mortality rates
Question from Jessica:
We are very fortunate to have a supportive spay/neuter clinic in our area to whom we take a lot of our feral cats, but our mortality rate is much higher than what you suggested in a previous answer. We have had at least 10 cats die in the past year out of the approximately 1,000 cats and kittens we have done there, maybe even a few more. When we raise our concerns the staff explains that this is to be expected, because feral cats cannot be examined or given any pre-op blood tests, etc., and also because ferals may be malnourished and under greater stress than the companion animals on whom they do surgery.We suspect there may be an issue with their anesthesia protocols but don't know how to verify this nor how to discuss the issue with them without putting them on the defensive. The cats are sometimes still groggy 6 or 8 hours after surgery. But we also feel we are the advocates for the cats and must speak to them about this high mortality rate.
We really appreciate all they have done for our feral cat program and want to keep a good relationship. However, it is uncomfortable to always worry that the cats we take in may not make it out. Can you suggest what we should be looking for to help pinpoint the potential areas causing this problem and how we could document it, since we are not vets or medical professionals?
Response from Julie Levy:
The first step is to document the actual mortality rate. Exactly how many animals have died compared to how many have been anesthetized? The next step is to institute a policy of having necropsies performed on all of the cats that die. We do this, and approximately half of cats that die have an identifiable contributor such as heartworms, cardiomyopathy, cancer, etc. Sometimes it is due to a surgical error that leads to hemorrhage. This is important to know, so we can inform our surgeons ofany problems encountered in their patients.
I do agree that feral cat anesthesia and surgery presents some special challenges that pet cats do not. They are extremely stressed, they may have poor body condition and large parasite burdens, traumatic injuries, or undetected metabolic problems or cardiopulmonary diseases. Since we cannot examine the cats before anesthesia, we are at a disadvantage in protecting their health.
If the death rate appears too high, then a close examination of the causes of death, as well as any procedures that may have changed or might not be optimal for feral cats should be carried out. Why did cats die and in what stage of their care did it occur? Sometimes procedures evolve without anyone being aware of it, so an advisory visit from someone who does not usually work at the clinic can be helpful.
Long anesthesia recovery times are a problem for cats in Operation Catnip as well. We use injectable anesthesia, and some cats are not fully recovered until the following morning. This can cause problems in kittens, who may develop hypoglycemia if they fast too long.
A thorough review of the findings over time will help you to determine if there are systematic problems or this was just a bad year. Our fatality rate varies a lot from year to year, but over time, it averages 3.5 cats/1,000.
