Wednesday, May 27, 2009

Effects of Early Neutering

This is an excellent article from

Early Spay-Neuter Considerations
for the Canine Athlete by Chris Zink, DVM, PhD

Neuter or not?
Those of us with responsibility for the health of canine athletes need to continually read and evaluate new scientific studies to ensure that we are taking the most appropriate care of our performance dogs. This article provides evidence through a number of recent studies to suggest that veterinarians and owners working with canine athletes should revisit the standard protocol in which all dogs that are not intended for breeding are spayed and neutered at or before 6 months of age.

Orthopedic Considerations
A study by Salmeri et al in 1991 found that bitches spayed at 7 weeks grew significantly taller than those spayed at 7 months, who were taller than those not spayed (or presumably spayed after the growth plates had closed).(1) A study of 1444 Golden Retrievers performed in 1998 and 1999 also found bitches and dogs spayed and neutered at less than a year of age were significantly taller than those spayed or neutered at more than a year of age.(2) The sex hormones, by communicating with a number of other growth-related hormones, promote the closure of the growth plates at puberty (3), so the bones of dogs or bitches neutered or spayed before puberty continue to grow. Dogs that have been spayed or neutered well before puberty can frequently be identified by their longer limbs, lighter bone structure, narrow chests and narrow skulls. This abnormal growth frequently results in significant alterations in body proportions and particularly the lengths (and therefore weights) of certain bones relative to others. For example, if the femur has achieved its genetically determined normal length at 8 months when a dog gets spayed or neutered, but the tibia, which normally stops growing at 12 to 14 months of age continues to grow, then an abnormal angle may develop at the stifle. In addition, with the extra growth, the lower leg below the stifle likely becomes heavier (because it is longer), and may cause increased stresses on the cranial cruciate ligament. In addition, sex hormones are critical for achieving peak bone density.(4) These structural and physiological alterations may be the reason why at least one recent study showed that spayed and neutered dogs had a higher incidence of CCL rupture.(5) Another recent study showed that dogs spayed or neutered before 5 1/2 months had a significantly higher incidence of hip dysplasia than those spayed or neutered after 5 1/2 months of age, although it should be noted that in this study there were no standard criteria for the diagnosis of hip dysplasia.(6) Nonetheless, breeders of purebred dogs should be cognizant of these studies and should consider whether or not pups they bred were spayed or neutered when considering breeding decisions.

Cancer Considerations
A retrospective study of cardiac tumors in dogs showed that there was a 5 times greater risk of hemangiosarcoma, one of the three most common cancers in dogs, in spayed bitches than intact bitches and a 2.4 times greater risk of hemangiosarcoma in neutered dogs as compared to intact males.(7) A study of 3218 dogs demonstrated that dogs that were neutered before a year of age had a significantly increased chance of developing bone cancer.(8) A separate study showed that neutered dogs had a two-fold higher risk of developing bone cancer.(9) Despite the common belief that neutering dogs helps prevent prostate cancer, at least one study suggests that neutering provides no benefit.(10) There certainly is evidence of a slightly increased risk of mammary cancer in female dogs after one heat cycle, and for increased risk with each subsequent heat. While about 30 % of mammary cancers are malignant, as in humans, when caught and surgically removed early the prognosis is very good.(12) Luckily, canine athletes are handled frequently and generally receive prompt veterinary care.

Behavioral Considerations
The study that identified a higher incidence of cranial cruciate ligament rupture in spayed or neutered dogs also identified an increased incidence of sexual behaviors in males and females that were neutered early.(5) Further, the study that identified a higher incidence of hip dysplasia in dogs neutered or spayed before 5 1/2 months also showed that early age gonadectomy was associated with an increased incidence of noise phobias and undesirable sexual behaviors.(6) A recent report of the American Kennel Club Canine Health Foundation reported significantly more behavioral problems in spayed and neutered bitches and dogs. The most commonly observed behavioral problem in spayed females was fearful behavior and the most common problem in males was aggression.(12)

Other Health Considerations
A number of studies have shown that there is an increase in the incidence of female urinary incontinence in dogs spayed early (13), although this finding has not been universal. Certainly there is evidence that ovarian hormones are critical for maintenance of genital tissue structure and contractility.(14, 15) Neutering also has been associated with an increased likelihood of urethral sphincter incontinence in males.(16) This problem is an inconvenience, and not usually life-threatening, but nonetheless one that requires the dog to be medicated for life. A health survey of several thousand Golden Retrievers showed that spayed or neutered dogs were more likely to develop hypothyroidism.(2) This study is consistent with the results of another study in which neutering and spaying was determined to be the most significant gender-associated risk factor for development of hypothyroidism.(17) Infectious diseases were more common in dogs that were spayed or neutered at 24 weeks or less as opposed to those undergoing gonadectomy at more than 24 weeks.(18) Finally, the AKC-CHF report demonstrated a higher incidence of adverse reactions to vaccines in neutered dogs as compared to intact.(12)

To spay or not to spay

I have gathered these studies to show that our practice of routinely spaying or neutering every dog at or before the age of 6 months is not a black-and-white issue. Clearly more studies need to be done to evaluate the effects of prepubertal spaying and neutering, particularly in canine athletes.

Currently, I have significant concerns with spaying or neutering canine athletes before puberty. But of course, there is the pet overpopulation problem. How can we prevent the production of unwanted dogs while still leaving the gonads to produce the hormones that are so important to canine growth and development? One answer would be to perform vasectomies in males and tubal ligation in females, to be followed after maturity by ovariohysterectomy in females to prevent mammary cancer and pyometra. One possible disadvantage is that vasectomy does not prevent some unwanted behaviors associated with males such as marking and humping. On the other hand, females and neutered males frequently participate in these behaviors too. Really, training is the best solution for these issues. Another possible disadvantage is finding a veterinarian who is experienced in performing these procedures. Nonetheless, some do, and if the procedures were in greater demand, more veterinarians would learn them.

I believe it is important that we assess each situation individually. For canine athletes, I currently recommend that dogs and bitches be spayed or neutered after 14 months of age.


1. Salmeri KR, Bloomberg MS, Scruggs SL, Shille V.. Gonadectomy in immature dogs: effects on skeletal, physical, and behavioral development. JAVMA 1991;198:1193-1203
3. Grumbach MM. Estrogen, bone, growth and sex: a sea change in conventional wisdom. J Pediatr Endocrinol Metab. 2000;13 Suppl 6:1439-55.
4. Gilsanz V, Roe TF, Gibbens DT, Schulz EE, Carlson ME, Gonzalez O, Boechat MI. Effect of sex steroids on peak bone density of growing rabbits. Am J Physiol. 1988 Oct;255(4 Pt 1):E416-21.
5. Slauterbeck JR, Pankratz K, Xu KT, Bozeman SC, Hardy DM. Canine ovariohysterectomy and orchiectomy increases the prevalence of ACL injury. Clin Orthop Relat Res. 2004 Dec;(429):301-5.
6. Spain CV, Scarlett JM, Houpt KA. Long-term risks and benefits of early-age gonadectomy in dogs. JAVMA 2004;224:380-387.
7. Ware WA, Hopper DL. Cardiac tumors in dogs: 1982-1995. J Vet Intern Med 1999 Mar-Apr;13(2):95-103
8. Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters D, Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1434-40
9. Ru G, Terracini B, Glickman LT. Host related risk factors for canine osteosarcoma. Vet J. 1998 Jul;156(1):31-9.
10. Obradovich J, Walshaw R, Goullaud E. The influence of castration on the development of prostatic carcinoma in the dog. 43 cases (1978-1985). J Vet Intern Med 1987 Oct-Dec;1(4):183-7
12. Meuten DJ. Tumors in Domestic Animals. 4th Edn. Iowa State Press, Blackwell Publishing Company, Ames, Iowa, p. 575
13. Stocklin-Gautschi NM, Hassig M, Reichler IM, Hubler M, Arnold S. The relationship of urinary incontinence to early spaying in bitches. J. Reprod. Fertil. Suppl. 57:233-6, 2001
14. Pessina MA, Hoyt RF Jr, Goldstein I, Traish AM. Differential effects of estradiol, progesterone, and testosterone on vaginal structural integrity. Endocrinology. 2006 Jan;147(1):61-9.
15. Kim NN, Min K, Pessina MA, Munarriz R, Goldstein I, Traish AM. Effects of ovariectomy and steroid hormones on vaginal smooth muscle contractility. Int J Impot Res. 2004 Feb;16(1):43-50.
16. Aaron A, Eggleton K, Power C, Holt PE. Urethral sphincter mechanism incompetence in male dogs: a retrospective analysis of 54 cases. Vet Rec. 139:542-6, 1996
17. Panciera DL. Hypothyroidism in dogs: 66 cases (1987-1992). J. Am. Vet. Med. Assoc., 204:761-7 1994
18. Howe LM, Slater MR, Boothe HW, Hobson HP, Holcom JL, Spann AC. Long-term outcome of gonadectomy performed at an early age or traditional age in dogs. J Am Vet Med Assoc. 2001 Jan 15;218(2):217-21.

Thursday, May 21, 2009

Puppies trying to "run the show"...

This is a response to an email from one of my new puppy owners re: puppies trying to "run the show"...

This is easier to explain in a live conversation. He's basically decided to manipulate you, because he can.

They need a firm, but loving approach to raising. I wish you could watch Luna interact and play with them. She is very rough, she is not gentle in any way, and she puts their entire heads and bodies in her mouth and holds them in a vice grip until they are squealing, running, and desperately trying to get away from her because what started out as play turned very quickly into 'mommy' having complete and total control over them and took it to a level for them that was unpleasant, and she didn't let them get off the hook easily (she continued to pursue them and bat at them with her front paws, and maul them, and chase them ....all playing from her perspective.... but ultimately they got overwhelmed and decided, "this isn't fun anymore"). Once they flee, she leaves them alone, they leave her alone.

When they bark at me, I scare the crap out of them and lunge at them and bark or shout back and say "enough" or no. I basically go after them like Luna would and make their "demand" unpleasant because I give it right back to them. Here's a classic example of what Shillelagh (O'Leary) was doing to Stephanie yesterday. Stephanie crawled in her crate with her and Shillelagh was relentless about eating her hair and biting at her. The more Stephanie laughed, the more out of hand Shillelagh became. To Shillelagh, Stephanie was a littermate to chew on. To Stephanie, she couldn't get control of the puppy and make her stop. I intervened and reached in the crate, grabbed Shillelagh by her lower jaw with my right hand, while pressing my thumb nail down....HARD... on her tongue. As she backed away and pulled her head away, I kept pressing and she squealed. When she was opening her jaws and backing up to get away from me, because now the fun game became unpleasant for her, I said in a firm tone, "Leave it!". She didn't touch Stephanie again! I am not abusive with them, but I am not gentle either.

The puppies were the hardest on Alyssa, my youngest, because they would gang up on her and all maul her at the same time. I would go after them like a mad woman and they learned really fast, stay away from Alyssa! I also taught Alyssa how to establish her dominance over them, how not to run away from them and encourage the chasing, and how to "pop" them if they started jumping up on her. Don't misunderstand discipline as abuse, it's not. Those of you that have owned dogs and large animals know what I'm talking about. It's about establishing under no uncertain terms, that you (and all humans for that matter) are the ALPHA over the dog, at ALL times! Nothing is for free. Start using their meals as training opportunities. I had a trainer once recommend the entire meal to be fed through training spurts throughout the day. She also taught me how to teach my dogs that NOTHING is free. They must earn their right to everything in their lives, and you are the resource! They need you to survive.

George (O'Manny) used to love barking at me when I was reprimanding an overzealous puppy that was jumping up on me. If I was disciplining his littermate, he'd bark and bark and bark. I'd finish the discipline, then run after George and grab him by the scruff of the neck and roll him over sideways until he yelped and relented and thought to himself, "why did she do that to me, that wasn't cool?". They learn quickly to do what is pleasant and to do what I expect, because if they don't, I'll turn into Luna and do unpleasant things to them!

Lets take nail dremmeling for example. They don't like it! They squirm, squeal, bite at my hand, bite at the dremmel, anything they thing they can do to get away from the undesired task. The more they bite, squirm, or squeal, the firmer my grip gets. They'll even pee on themselves and me. Because I'm always alone when I do the nails (no one to hold peanut butter to distract them), I will wrestle with them for a few minutes before they finally realize I'm not giving up. Once they relax and give in, I get the job done quicker, praise lavishly when I'm done, then they can carry on about their business. As we progress through each Sunday, they actually figure out from week to week the less they struggle, and the more cooperative they are, the faster I get the nail dremmel job done and the faster they get to go back to whatever it was they were doing. They are not dumb dogs, but they will make you feel like dumb owners.

I have 15 years of expeience and have raised so many Swissy puppies, I think I actually think like a Swissy. They are going to be testing boundaries and limits with you all. I highly recommend Karen Pryor's book on "Don't Shoot the Dog". Swissies love to please you and make you happy. They aim to please, always remember that. They'll do anything for a snack, treat, or foodl.

If they jump up a lot, which Luna does and her mother, Rixey,'ll have to work really hard on the sit stay. They get no love, no food, no treats, NOTHING, unless they are sitting first. When their leash is attached, you can step on it quickly so they can't jump up. DO NOT let a 100+ pound animal jump up on you. MAKE THEM SIT or DOWN first. They will learn, because they want to please you. If you establish this now, while they are little and puppies, the sit or down will become a habit. I had to "rewire" Luna from an automatic sit when greeting family or strangers, to actually commanding her to a "stand stay" when she was in the ring being judges. It was worth it to me to keep her feet "four on the floor" when she would first sit for judges on examination.

Imagine the concept of a 100 pound mother staving off 9 ravenous little puppies wanting to nurse, when she's dried up and doesn't want them to nurse. It is not a pretty scene for several minutes. The most stubborn ones keep coming back for more, and the more they come back to try and nurse, the more aggressive and firm Luna gets. She tries with just a bark warning, but then she'll actually chase away and pin down the ones that don't get her first warning....and I've seen her have them completely on their backs with their entire heads in her mouth and she won't stop until they turn into jello and just lay there, completely relaxed.....submitting, basically.

When they jump up on me, I grab their little paws and hold onto them and squeeze in between their pads. The don't like it, they pull back, then they squeal. When they realize that if they do something unpleasant to me, I'm going to return something unpleasant to them, they figure out really quickly to act and behave in socially acceptable ways.

As for the biting, I would scream bloody murder and scare the daylights out of the puppy, even though it didn't actually hurt. I like to set the precedent and tone that human skin is like butter. When they chew on each other, they know their limits by how loudly the puppy being bit screams or gives it back to them.

While they are still young and impressionable, you need to become "mom" and establish dominance over them at all times.

Shillelagh is really vocal about being in the crate while she can't see us, but she hears us. Last night, every time she started to bark or whine, I squirted her from a distance with a water bottle. She was not happy. She continued to bark, I continued to squirt. She was soaking wet, but figured out in about 10 minutes, if I bark, I get squirted, if I'm quiet, no one squirts me. The water didn't hurt her, but getting wet was unpleasant. If you return your discipline with something unpleasant to them, they figure out pretty quickly they don't want to experience unpleasant things.

Hope this helps!