Reproduction Topics in Dogs

Melarsomine (Immiticide Rx) and Fertility

Q: How does Immeticide affect a dogs fertility??


A: Cherie-

The safety of melarsomine (Immiticide Rx) was not determined for dogs who might be used for breeding purposes in the studies done for FDA approval. It is an organic arsenical compound, which is similar to the original heartworm treatment medication, thiacetarsemide sodium (Caparsolate Rx). While this medication was also apparently never really tested for use in dogs intended for breeding I know from our practice experience that it did not appear to impair future reproductive capability to treat dogs with thiacetarsemide, as we had a number of both female and male dogs who were successfully bred following heartworm treatment. To the best of my ability to remember these things, we have only had one female dog who has been bred following treatment with melarsomine, so far, and there were no problems with the bitch or the puppies.

There is also no information that I can find on treatment of pregnant bitches with melarsomine but I would strongly advise not attempting treatment of a pregnant bitch. We inadvertantly treated one pregnant bitch with thiacetarsemide and all of the fetuses were deformed and died. Perhaps this was coincidence, but I doubt it. I strongly suspect that the potential for similar complications with melarsomine would be high.

I am sorry that I was not able to find more specific information.

Mike Richards, DVM     

Male Dog Suddenly Interested in His Spayed Mother.

Q: Hi! Dr. Mike, I am a new subscriber. I have a 5 1/2 yr old spayed female standard poodle (Satin). Was spayed at age 3 1/2 after having 1 litter. Out of her litter I kept 1 male pup now age 2. For the past 2 weeks my male dog has been all over his mother as if she were in heat. I took her in to my vet thinking maybe a bladder infection. The urine test showed no signs of infection. We put her on keflex he said in case of vaginitis? She's been on it a week and so far the male dog is still very interested. Are there other conditions that can cause a spayed female to attract a male? There are no close neighbors with females that I'm aware of. She has no vaginal discharge. I've checked that often. Thanks, Kathy  

A: Kathy-

It was pretty smart to consider the possibility of a close by female in heat. Many male dogs will get excited enough by the presence of a female in heat to consider attempting to breed another female who is available but not in heat. Some male dogs seem to be able to detect females in heat over a very long distance so this might still be worth thinking about, especially if the behavior stops.

It can also help to see if a female that seems attractive to one male is attractive to other males.

Having your vet check a swab sample from the vagina to look for signs of estrus or to draw blood for hormonal analysis is also reasonable, especially if this situation repeats itself or if she shows other signs of estrus or of false pregnancy as time goes on.

Sometimes, a small amount of ovarian tissue gets left behind during a spay procedure and this can lead to true estrus occurring in a female dog who is spayed. These females can not get pregnant but it is still better to try to find the ovarian remnant and remove it. There is a test procedure, using human chorionic gonadotropin (HCG) during an apparent episode of estrus to see if it will cause a rise in progesterone levels, indicating functional ovarian tissue is present.

The other possibility is that her son has decided he wants to be the dominant dog and has started to mount her in an attempt to show dominance. It can be really hard to distinguish this from sexual behavior in some cases.

Once in a while cystitis (bladder infection) or vaginitis does seem to make a female dog attractive to males, for reasons that aren't entirely clear, so it is reasonable to treat for this possibility.

Hope this helps some.

Mike Richards, DVM   

Swelling of the Mammary Glands During and After Estrus

Q: Dr. Richards,

Our 11-month old female French Brittany came into her first heat period last month. At that time she had some hardness & swelling in her breasts. The condition has not gone away. Is this a problem to be concerned as I intend to use her for breeding in the future?


Answer: Herbert-

Swelling of the mammary glands during and after estrus in dogs is normal. Dogs have heat periods at such long intervals, compared to other species, because they do not reject the corpus luteum, which produces progesterone which exerts effects similar to a pregnancy, causing the mammary enlargement.

Hardness in the mammary glands is a concern, though. This sometimes indicates a mammary gland infection. It would be a good idea to carefully palpate (examine by hand) her mammary glands several times during the period during and for up to three months after her heat period to be sure you don't miss a mammary gland infection. If the area is hot to the touch, very tender or if there are soft spots in an area that is otherwise hard, you should contact your vet.

This probably won't be a problem in the future but it is a good idea to be cautious.

Mike Richards, DVM   

Breeding Problem

Q: Dr. Mike I have a question about strictures in dogs on a German shepherd female. The male is not able to get a tie and is an experienced stud. Upon checking her she is very tight. Thank you, Barbara.  

A: Barbara-  

If your shepherd is currently in heat (as it seems) and if the male will not breed with her due to a vaginal defect, it would take some luck to have a defect that could be corrected on this heat period in time for a successful breeding. It would probably be better to consider artificial insemination if your vet feels that the problem won't interfere with delivering puppies or if it can be corrected post-breeding but before the puppies are born. A cesarian section is another possible option in this case but this is a higher risk in dogs than in humans and that has to be factored into any decision to breed.

I can provide more specific information about the different types of vaginal defects and the treatment of those defects if you need it.

Mike Richards, DVM 

Vaginal Hemolytic Strep  

Q: Could you please send me information on the above: how contracted, symptoms, treatment, etc. Thank you.


A: Mary-

I am not sure that I can supply this information reliably. This is one of many issues in veterinary medicine that appears to be unresolved. Beta hemolytic strep are normal residents of the vaginal tract in bitches, according to a couple of reference books I have and at least one published study ( Bjurstrom and Linde-Forsberg, May 1992 issue of the American Journal of Veterinary Research) and this makes it very hard to decide when it is a pathogen (capable of causing disease) and when it is not. In addition it makes issues like whether or not it is infectious harder to figure out, too. Still, there are veterinarians who seem to be pretty sure that it can cause problems in some circumstances. Other bacteria that are normal residents of other parts of the body, such as the respiratory tract, are often suspected of causing disease in some circumstances, too,  so it makes sense that beta-hemolytic strep could be a problem sometimes. If there is no detectable vaginal disease and no history of reproductive problems I would be reluctant to treat a bitch based on culturing this organism on a random culture. If there is visible disease, reproductive problems that there does not appear to be another explanation for or something like that going on, I would try to use an antibiotic selected through culture and sensitivity testing. This is all pretty hypothetical for me, though.  I can't even recall the last time we did a vaginal culture in our practice so you may want to find a theriogenologist (veterinary reproduction specialist) and discuss your concerns if there is a current problem you are trying to deal with. Most veterinary colleges have at least one theriogenologist. Your vet can refer you if necessary.

Mike Richards, DVM      


Q: What is the average gestation for large breed dogs? More specifically, English Mastiffs? Thanks. Kimberly

A: Kimberly- All dogs have the same gestation period regardless of the breed. The gestation period for dogs is 58-65 days, the average being 63 days. The gestation period needs to start the day of the first breeding not the last since you cannot be certain when the bitch is actually bred. If the gestation period falls anywhere out of that time frame, your veterinarian should be contacted.

Mike Richards, DVM    

Mycoplasma and Canine Reproduction

Q: What are symptoms? Can a bitch who did not have mycoplasma pick it up being bred, and if she does, will she get pregnant? Will she have puppies? Can my vet test for mycoplasma now, when a bitch is well into her pregnancy? How to avoid it??? If my bitch has picked it up, will the other dogs get it? What to do?

A: Margaret- I am sorry for the delay in replying to your question. There is some controversy about the whole issue of mycoplasma and its effect on canine reproduction. The major reason for the questions is the abilty to culture mycoplasma from clinically normal bitches approximately 60% of the time. Since that would make mycoplasma a normal inhabitant of the female reproductive tract, figuring out when and if it causes infertility problems is very difficult to do. It is conceivable that it does cause problems in some bitches but it is also very likely that it is being blamed for problems from another cause simply because it is present when bad things happen. If culturing for this organism still seems desirable to you, it can be done but your vet will have to order a special swab for the culture (a guarded swab helps a lot in isolating the organism) and the lab will have to be alerted to look for this organism since it requires special growth media. Mycoplasma organisms are sensitive to tetracycline antibiotics if they are present but there is an good chance that you will just be killing non-harmful residents of the reproductive tract and missing whatever the real problem is unless it also happens to be sensitive to tetracycline antibiotics.

Mike Richards, DVM    

Delaying First Estrus

Q: Dear Dr. Mike, Your address was given to me by a friend in Vancouver and I hope you can direct me to better information than I've located here in Santorini. I have a 5 and a half month old Rhodesian Ridgeback who plays every day on the beach with her other doggie friends. My worry is that she might possibly go into heat quite soon and I would like to protect her from an unauthorized pregnancy. I am seriously consdering breeding her next year so I don't want to spay her just yet, but the only veterinary advice I can get here is limited and often seems dated to me. Our vet uses injections of some sort to control fertility and I'm not sure if this is safe, or what the side effects might be. I'd like to find out more about birth control for Miss Grace, as well as when I might expect to encounter this problem. So far, she seems highly uninterested although there are some rather eager poodles following her around. Thank you for your time and I look forward to your insight. Sincerely, Majda and Grace.

A: Majda- I am pretty sure that there is no method of stopping or delaying estrus that is suitable for use in a first estrus situation. To the best of my knowledge all of these products suggest use in the second or subsequent heat periods only. My best advice is to watch her carefully, keep her confined where it is impossible for male dogs to get to her and do not attempt to walk her alone during the heat period. I have had several clients who were unable to fend off amorous males during estrus while walking their bitches on a leash. Two people, walking together, can usually handle any males that might appear.

Mike Richards, DVM

Herpes Virus Titer

Q: Dear Dr. Mike, I have a Brussels Griffon bitch who is currently bred (should be about 28 days pregnant). Her first litter of four was lost to herpes virus. Her titer tested high before she was bred this time. I'm hoping we can avoid this disaster on this breeding, otherwise she will be spayed. I was told by knowledgeable toy breeders that giving folic acid during gestation would help in the avoidance of a) cleft palate and b) resorbtion (sp?). I'm giving her 200mcg of folic acid daily ....she weighs 10 lbs. Is this a reasonable dose for her size? Do you think there might be a connection between this nutrient and the problems mentioned? I'm aware that this is just anecdotal evidence I'm going on, and have no idea if there is a more scientific basis. Thank you for your time and knowledge. Joan

A: Joan- Usually dogs that lose puppies to herpes virus on their first litter have high enough titers against the disease to protect subsequent litters and the problem doesn't recur.

Folic acid can be given in dosages up to 5mg per day so the dose you are giving certainly seems to be in the safe range.

I am not aware of the benefits from it you mention (protection from losing litters and cleft palate) but that doesn't necessarily mean they aren't real benefits.

Mike Richards, DVM    

Behavioral Problems Pre and Post Season

Q: My 25 month old Doberman bitch becomes "freaky" about 2 months before her seasons and then once again about 3 weeks after. this is especially bothersome when trying to show her. I realize that most bitches have some behavioral changes associated with their seasons and I have found that this seems to get better as the bitches get older. My question is whether or not calcium supplements beginning several weeks before her season would hurt her. I know that calcium supplements can predispose to OCD in a puppy but I was wondering if a mature bitch would have any problems. I know that in people, research has shown that calcium supplements can prevent about 85% of the symptoms of PMS in women. Perhaps it could help in dogs as well. Before I try it, I'd like your opinion as to whether or not it could harm her. Thank you, Jean

P.S. I know that her behavioral changes 2 months before are hormonal because my male starts his marking in the house like clock work at this time.

A: Jean - It is unlikely that calcium supplementation would cause problems in an older dog unless she was bred during the heat. Excess calcium supplementation during pregnancy seems to predispose the bitch to eclampsia (hypocalcemic seizures). I do not know if it would help but can not see any reason not to try it and see.

Mike Richards, DVM

Lab Won't Breed

Q: Dear Dr.Mike, I have a three year old yellow lab that I recently tried to breed. We waited about a week to ten days after we noticed she was in heat and brought her to the breeders house. Every time the male went to sniff her she swung around and put up her hair. We tried two different males. She acted the same way toward both of them. We tried about every day after that for a week or so. I never noticed a change in the color of her discharge. I don't know what we did wrong. Do you think she is a dog that will never be able to be bred? Should we try again next heat cycle or have her done artifically. I would really apperciate your advise it would help a great deal. Thanks for your time.

A: There could be several things going on. The behavior of your female indicates she may not have been in true estrus - that part of the heat cycle when the female will allow a male to breed her. Most females growl or snap at the male when they are not quite ready for breeding because they still may be in the proestrus phase of the cycle. The proestrus stage usually lasts from 4-9 days and includes signs of bleeding, vulvular swelling and increased urination but this stage can last up to 2-3 weeks in some animals. Heat cycles vary from dog to dog and most of the numbers written are averages so this needs to be taken into consideration when deciding the time for breeding. Other females will exhibit this behavior when they are frightened, even if they are in true estrus. It is best to keep a log if possible of when the heat cycle starts - when bleeding and swelling is first noticed, when those signs disappear, etc. and time interval between heats if you have not already done so. This may help with determining the length of her cycle. Having your veterinarian perform cytology during the heat cycle will also help determine the optimum time for breeding. Using progesterone and lutenizing hormone testing may allow an even closer estimation of the time of ovulation. Some females would rather be bred at home instead of being taken to the male - feeling more comfortable on familiar territory. Other females may feel more comfortable (if bringing her to the male) to bring her a week or so before the expected heat (reason for the log), boarding her at the male's home so they can see each other and allowing them to breed on "their" terms. Then there are those females that will not breed no matter what. If it is really important to have a litter from a particular female that will not breed no matter what is tried, there is always artificial insemination.

The most common mistake in breeding dogs is simply missing the time when they are receptive to the male. This can happen as early as 2 or 3 days into the estrus and can be as late as 21 days after first signs of bleeding and vulvar swelling. The best approach is to attempt breeding every other day from the first days of the heat period. The only problem with this is that it requires a lot of cooperation from the owner of the stud dog.

Good luck!

Mike Richards, DVM

At What Age Fertile

Q: I have this bitch who gave birth to a couple of lovely puppies about five months ago, now my question is, these puppies are attempting to mate with their mother, I have no idea as to how successful they've been but nonetheless I'm very worried, I'd like to know if these five month old dogs could make her pregnant, do they produce gametes at such an early age? I've talked to a couple of veterinarians and they've told me about the ways to avoid these problems, such as an injection that makes her sterile for a couple of months and the surgical alternative, the last one being very cruel, in a way removing the dogs reason for existing and leaving offspring. Is it safe to apply the injection at home or should i let a professional do it? I have absolutely no idea of how to go about this and what substances to use. I would greatly appreciate an answer. Keep up the good work!

A: It is very unlikely that 5 month old dogs can impregnate a female but not totally impossible. A few dogs do become fertile in this age range. I am not aware of an injection that will postpone estrus that is still available. The only product for postponing estrus that I am aware of is megestrol acetate, which is available as Ovaban or MegAce. Both of these are prescription products and your vet would need to prescribe them. There is an increased risk of pyometra with the use of progesterone products to delay estrus but for some situations this is an acceptable risk.

I am somewhat baffled by your perception that spaying a female dog is cruel. The majority of my female patients are spayed and they seem to enjoy life and to participate in family activities with the same enthusiasm as they always exhibited. They just don't get pregnant and produce puppies. It would be nice if there were homes for all the puppies born but that just isn't the case and breeding responsibly is very important due to this. In addition, there are some health benefits for the female dog associated with spaying, including freedom from the complications of birthing puppies, reduced risk of mammary cancer and uterine infections. Uterine infections (pyometra) are a serious problem in dogs due to the way in which they cycle and can easily result in death. Veterinarians see the downside of reproduction much more than the positive side in our day to day practice of medicine and I believe that some clients do feel that we miss the good points --- but that it the perspective the job gives us!

Mike Richards, DVM


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...