What causes miscarriage in dogs? When your whole litter of puppies died, you’re left wondering what happened. Canine brucellosis is always in the back of our mind, and it needs to be the first one ruled out. There are, however, other infectious causes of dog miscarriage:

Leptospirosis in Dogs

Leptospirosis has once again become a major player the last few years. The Lepto vaccination was abandoned in breeding female dogs the past ten years, which created a lack of immunity in breeding populations. Lepto is carried by wildlife and rodents, a major reservoir for the disease. It results in late-term abortion or embryo death, causing one or two puppies to die before whelping starts. There have also been a couple cases in recent years in which a mom aborted the whole litter in late gestation. However, abortion storms are not common.

Leptospirosis Diagnosis in Dogs
Diagnosis can be made with the aborted puppies – ice them down and get them to the lab as soon as possible. Lepto can also be diagnosed by measuring a rising titer with mom. On a single sample titer, you must know what titer the lab calls a positive; positive levels differ from lab to lab. If the dam is not vaccinated, the titer is caused by wild Lepto. If the female was vaccinated, the Lepto titer could be caused by the vaccine – a two sample rising titer will diagnose.

For a rising titer, we draw blood on mom as soon as abortion happens and repeat in three to four weeks. If the first is, for example, 1:100 and the next titer is 1:1000, then it is Lepto. Rising titers are a bit confusing to understand, but if the titer raises fourfold, the result is positive with the cause being mom fighting Lepto infection. This gives you the diagnosis.

How to Prevent Leptospirosis in Dogs
Leptospirosis hates dry environments and does not survive long in desert conditions, unless there is water. Eliminating standing water and being sure your kennel runs and exercise areas are on a well-drained slope will decrease exposure. Most Lepto bacteria are acquired from water contaminated with urine from wildlife or rodents. Eliminating the chance of standing water decreases your chance of exposure. You see the benefit of building kennels on raised decks to avoid exposure to Lepto and parasites.

Lepto vaccination is the cure for diagnosed Lepto abortion and will shut the puppy losses down quickly. Vaccinate twice, two weeks apart to get maximum immunity fast. Parvocidal disinfectant will be effective in eliminating the bacteria from the area. Breeding stock on the ground is at risk and should all be vaccinated yearly, especially in high-Lepto areas.

Strep Zoo in Dogs and Other Strep Canis Species

It is difficult to evaluate the fertility role in Strep as we find Strep species in normal females’ vaginal cultures. Streptococcus zooepidemicus (Strep Zoo) has been found to cause infertility and has been cultured from placenta of puppies that are born dead.

Strep Zoo in Dogs Symptoms
Kennels with Strep Zoo can start with minor respiratory issues and then later move to infertility or puppy death; however, you do not have to see a respiratory issue to have the reproduction issue. When things do not quite fit, look for bacteria and especially Strep Zoo. Breeders often report females starting to belly down, then suddenly looking empty. Some report minor vaginal discharge but most will not be apparent. The embryo is killed before bone development so mom reabsorbs fetus.

Diagnosis
You can diagnose using the horse PCR test for Strep equi subspecies zooepidemicus. It seems to be reliable. Humane groups have lost dogs due to respiratory issues with Strep Zoo, but there is no knowledge of kennels to date with respiratory death issues.

Strep Zoo in Dogs Treatment
Respiratory issues have been easily treated with Clavamox. Breeding issues are solved by putting the female on antibiotic while in heat, continuing until the female is out of heat. We repeat the antibiotic at whelping for one week after giving birth. Our goal is to eliminate Strep from the reproductive tract when most susceptible to uterine infection – when cervix is open – breeding and whelping. Some have tried flushing the uterus with antibiotic while in heat, but the benefits have not been proven. Most specialists are moving away from flushing the reproductive tract because of irritation and the risk of introducing additional bacteria into the uterus with the procedure.

Canine Herpes and Breeding

Canine herpes is a big contributor to puppy death in the first week of life. The most susceptible time is three weeks before and three weeks after birth. Puppies are often born alive – exposed in vaginal vault to herpesvirus – and “fade out.” In uterus herpesvirus exposure, you can get mummies and live babies in one litter. If the puppy is alive at one week of age, the puppy usually makes it. After three weeks of age, they rarely have issues.

Herpes in Puppies
Within three days of exposure, the herpesvirus is systemic and throughout the body. Because the virus is temperature sensitive, we can raise environmental temp from 101º to 103º F on exposed babies to keep the virus from reproducing the first two weeks. Newborn temp is usually 2 to 4º F lower than that. A newborn temperature is dependent on environmental temperature and is incapable of fever production the first three weeks, which may account for the susceptibility of newborns to herpes. Moms will not like the high temp, so nursing will have to be managed.

Moms with titers to herpes will put antibodies in milk and that will protect the baby in the critical first three weeks of life. Puppies born to diseased moms with titers rarely have issues in spite of their infection because of maternal antibodies.

Puppies exposed to herpesvirus after three weeks often get respiratory signs and then recover. Mothers that have issues will birth normal litters in the future. However, they are infected for life.

In Europe there is a vaccine, (EUROCANherpes 205 by Merial), but no vaccine is available in the United States. We could use one.

Control
Herpesvirus is temperature sensitive and easily killed by disinfectants. Herpes is acquired from a carrier that is not showing disease. It is then introduced to dogs that do not have immunity to herpes. Once herpes is in the kennel, it is easily transferred in excretions to other dogs. All discharge from the body can have the virus, but vaginal discharge has the highest concentration of herpesvirus and is the usual source of infection transfer. Once the issue is identified, try to expose all maiden females before breeding to the virus in hopes of getting enough immunity to prevent puppy loss.

Serum from known recovered females is sometimes used and given to puppies orally at birth to supplement immunity in colostrum of first-time moms.

Mycoplasma in Dogs

Mycoplasma canis was introduced into U.S. from Eastern European imported dogs. It now causes respiratory issues (Kennel Cough) in puppies and occasionally reproduction issues. Most kennels with Mycoplasma reproduction issues started with imported breeding-age males or females, and it spread to other females. Embryo loss after breeding is the issue.

Mycoplasma in Breeding Dogs
We have treated all imported dogs as though they are infected to eliminate the carrier state. With adults, use Enrofloxin or Zithromax at labeled dose. For imported puppies that are still growing, use Doxycycline. Adults need 21 days minimum, while 14 days is adequate for a baby. Eliminating the reproduction problem once it is established can take months. Treatment involves both oral antibiotic and breeding on antibiotic the next year. Uterine flushes in heat have been used but as in Strep, it has risks. As with Strep, the organism will get into the uterus when the cervix is open.

What To Do If Dog Has Miscarriage

• Female infertility – Culture vaginal swabs while in heat and throat swabs are helpful. Most females are very clean, and we find help comparing both cultures.
• Aborted fetus or dead puppy with placenta – Ice it down in plastic bag and get to the diagnostic lab or veterinary clinic ASAP. Strep Zoo or bacteria can be identified out of the placenta, and Herpes or Lepto can be diagnosed from the dead puppies. Cultures of both are important.

Dog Miscarriage and Biosecurity

To prevent introducing disease with new stock, it is important to have biosecurity measures in place to test, deworm and vaccinate for prevention and isolate the addition until you are comfortable mixing with your bloodline. Always treat any new additions to your kennel as though someone just gave you the plague. If you are not careful in your prevention, it could happen!

If you have more questions on dog litter loss, dog miscarriage or fading puppy, call us at 800.786.4751.