Originally Published in The Cavalier King Charles Spaniel Club of Canada
Newsletter.
This is the time of year when we’re all starting to get really fatigued with winter in the northern climates, and when breeders start fantasizing about the upcoming litters they are planning, and dreaming of young puppies frolicking on new spring grass. Well, if you are one of those breeders, what can you do to improve the odds of having a healthy, infection-free litter?
Much of the information providing the foundation of this article is based on an article entitled, “MY HOLLY HOBBY – SHE PAID THE PRICE”, by Sandra Lemire, a Yorkie Breeder/Exhibitor. This article was posted on the VETMED-L mailing list on Tuesday, December 25, 1995 by Ms. Lemire’s friend, Isabel M. Gordon. The article has been edited both for length and so I could incorporate a broader spectrum of opinions from other knowledgeable persons as well.
Background Information
The problem first became apparent when a champion bitch, 55 days into whelp, started producing green vaginal discharge. The bitch was rushed to the vet for a caesarian section; two of three puppies survived. Shortly thereafter, another bitch, Holly Hobby, started showing a green discharge 12 days before her due date. She too was taken immediately to the vet’s for a c-section; one dead puppy and four live puppies too premature to survive were delivered. Three days after, the bitch herself died. Four more bitches in whelp also had problems. They all carried the pups to almost full-term, but the pups were lethargic and weak. One of the bitches resorbed one pup and delivered another that died shortly after birth. Another had to be sectioned; in addition, adhesions to the bladder were found, and the pups died. Altogether, within the space of four months, 14 out of 20 puppies had died; three c-sections were needed on bitches which had previously free-whelped, and a favourite bitch was dead.
Six different veterinarians were involved in trying to identify what was happening. All kinds of cultures for infections were taken, and autopsies were performed. The owner spent at least $2000 U.S.. since the problems began. In the end, it was determined the problems were caused by two bacteria that were “pathogenic” and highly resistant to all antibiotics except two. The pathogens involved were E. coli and an Enterococcus Group D (beta hemolytic strep). The author gives a very good background to understanding bacterial infections, as follows:
“For those who are unfamiliar with the term ‘pathogenic’, it is a term that is applied to a bacteria that is able to cause problem of infection to the host. It should be understood that bacteria are everywhere, and that most of them are harmless to their hosts. But sometimes when bacteria are subjected to an antibiotic, they develop a tolerance for that antibiotic, particularly if the antibiotic is only used for three or four days and then discontinued. The bacterial growth is temporarily slowed down and the patient seems to be improving and symptoms seem to be diminishing so the person administering the medication stops. The medication was merely slowing down the growth of the bacteria (which is what the antibiotic is designed to do) and as soon as the medication is withdrawn, the bacteria bounces back with new vigor AND tolerance for that particular drug. The result is that the bacteria is now stronger and a different medication must now be used to fight this bacteria because the first drug is no longer effective. When this pattern is repeated a few times, a ‘super germ’ is born.”
A bacteria is only considered to be pathogenic if the patient exhibits symptoms of a problem because disease has been caused. In the case of breeding bitches, those symptoms may not be apparent until close to whelping, and it is too late to control the bacterial growth. Bacteria are considered to be “resistant” when they have the ability to counteract or resist the effects of antibiotics. As Eric R. Lewis, DVM, noted in a follow up post on December 30, 1995, pathogens cause disease and may or may not be resistant to antibiotics. For example, just because E. coli becomes resistant, that does not make it a pathogen, and just because E. coli becomes pathogenic, does not make it resistant.
Antibiotic therapy
Bitches in whelp should only be taking antibiotics when under a veterinarian’s supervision, and they should receive the full course of medication ordered (usually at least 7 or 14 days). During the medication and for a week afterwards, you might want to consider offering the bitch plain yogurt (with active lactobacillus acidophilus cultures) in addition to her diet. When antibiotics are taken, they not only affect the pathogenic bacteria, but also the “good” bacteria, which are a natural defense against vaginal yeast infections. Yeast infections do not appear to be harmful to a pregnancy, but they can be very uncomfortable. Eating the yogurt allows the vaginal tract to become repopulated with the bacteria that hold the yeast population in check.
Preventive practices
As a result of having the problems described, Ms. Lemire describes “The Lemire System” of reducing the likelihood of infections affecting the health of planned litters. It is described as follows:
“Females in heat are isolated from the first day that it is known they are in season. Females in heat are never caged together even if they are ‘roomies’ at other times. I use two and three story cages so there is no contact between cages. If a bitch is to be bred on this cycle she must have a vaginal culture and sensitivity done on about her 4th day of heat. As the tests take about four or five days to run, we have the results back before breeding. NO EXCEPTIONS! Even my own dogs are cultured every time. Males are tested before every breeding. I will only use males who are tested. Bitches in heat are kept in a separate room away from all males. Therefore, only the male that is assigned to breed the bitch is in contact with her. Dogs are never switched from cage to cage. Each cage is germicidally cleaned before and after a visitor. Each visitor is fed separately and any leftover food is thrown away. All dishes and bedding are washed in bleach water.”
A follow up post from someone who is a clinical microbiologist and a Weim breeder disagreed with taking a vaginal culture; her point was that most organisms in vaginal flora are normal. This area is not meant to be sterile. Someone else had suggested that a cervical or uterine culture (prior to pregnancy beginning) would more accurately reflect a pathogenic situation than a vaginal culture would. The caution is made that culturing and administering antibiotics without good reason might lead to more resistant organisms.
Known pathogens – Bacteria
This list is not exhaustive, but was compiled by Ms. Lemire based on her experience and the experiences of fellow breeders who reported back to her.
Escherichia coli (better known as E. coli) – This bacteria is one of the most pathogenic and can cause fetal death, toxemia, pyometra, and vaginal hemorrhage. Ms. Lemire indicates that traditionally the bacteria has been labeled as “normal flora” by most labs and practitioners, when in fact a big percentage of the E. coli are very dangerous to a pregnancy. If a dog carries E.coli on the sheath of his penis, he will most likely be unable to produce many live puppies. If he continues to carry E. coli in his sheath for a long time, it can render him permanently sterile. E.coli has the ability to invade the uterus during pregnancy, which used to be credited to brucellosis alone.
Pseudomonas – Ms. Lemire indicates that while this bacteria may be routinely found in the environment, her experience has shown if the bitch has it in her vagina, she will not be able to successfully breed the animal. Ms. Lemire has found the Pseudomonas to be quite resistant; out of five cases, there were no live births from bitches who cultured Pseudomonas, and only once was it even successfully eradicated.
Staphylococcus aureus – Eighty per cent of the time, this bacteria is not pathogenic. It can, however, attack puppies after birth. While the dam is usually mature enough to have developed a resistance, the puppies are not able to fight it. They may acquire the infection through the umbilical cord stump, from the dam’s licking. They can stop nursing, dehydrate, and fade away; Staph aureus can be one of the causes of “fading puppy syndrome”.
Corynebacterium – (one of the strains causes diptheria) – It is very pathogenic, and can cause severe infections in the bitch, as well as leading to fetal death. Males can become infected from breeding a bitch who has it. Very dangerous.
Beta hemolytic Streptococcus – This bacteria is very contagious, and if it is present at the time of breeding, the bitch may well not take. It can render a male sterile when carried in the sheath. If the bitch acquires an infection once she is already pregnant, the puppies can be born dead, dying, or can even die months later. Ms. Lemire has noticed the likelihood of uterine inertia/dystocia is increased when a beta Strep infection is present.
Listeria – This one can cause spontaneous abortions; in two cases in which it was not treated, the puppies died, and in one case, the bitch herself died. In the case where the bitch was treated in whelp, the puppies were born healthy, and all have done well.
Hemophilus influenza – In the cases witnessed by Ms. Lemire, infection with this organism always proved fatal to the puppies unless treated. It is the same bacteria responsible for spinal meningitis in children.
Proteus – Having a healthy pup delivered in the presence of this bacteria has never been brought to Ms. Lemire’s attention. She says, “If I hear of a bitch aborting green slime at about three or four weeks into whelp, I’m not surprised when a Proteus shows up.”
Klebsiella pneumonia – This organism is disease-producing in both man and animals. There is some evidence if owners often work in or visit nursing homes, they may transmit this bacteria to their bitches.
Known pathogens – Brucella canis
Brucella canis is a coccobacillus, meaning it is a type of bacteria. It is getting its own section in this article because it is the causative organism of brucellosis, one of the most serious infectious diseases which can invade your kennel. The form of brucellosis disease in people was long known as undulant fever. Three species of Brucella had been identified previously; in 1966, the species which targets dogs was discovered at Cornell University.
U.C. Davis School of Veterinary Medicine Book of Dogs (published by HarperCollins, 1995) discusses the disease, as do the Dog Owner’s Home Veterinary Handbook (published by Howell Book House, 1980) and The Merck Veterinary Manual (published by Merck & Co., Inc., 1991). About 1% of pet dogs and about 5% of stray dogs are affected. B. canus does not survive for lengthy periods outside the host, and in sunlight will die in a few hours.
Infection has caused a reduction of 75% in the number of pups weaned in some breeding kennels, and is the leading cause of late abortion (45 to 55 days gestation). Prolonged vaginal discharge usually follows abortions, and abortions may happen during subsequent pregnancies. Infection readily produces sterility in both dogs and bitches, without any obvious signs of disease. All ages and both sexes are equally vulnerable. Transmission from dogs to man, and even to other animals, has been reported.
Most commonly, transmission is accomplished at the time of breeding, and the highest incidence is found in animals which have been mated to carriers of the organism. Within a kennel, the disease can spread from dog to dog by ingestion through contact with infected secretions. In bitches, the organism is present in the greatest concentration in the placental and vaginal secretions; while in males, it is excreted in the semen. Even kennel runs and other surfaces can become contaminated, thus increasing the likelihood that other animals will become infected.
Dogs with evidence of infection may have enlarged lymph nodes in the groin or beneath the jaw, in conjunction with running a fever. Joints may be swollen and painful, too. The males’ testicles may swell, then go on to waste away as the sperm-producing cells are destroyed. Other animals may be considered to be in a subclinical or “carrier” state, but still capable of transmitting infection.
Positive diagnosis is usually made through a blood test; there are actually three types of tests that can be run. The most common is the rapid slide agglutination test (RSAT); it is very strongly recommended this is test is run on ALL dogs before mating. As false positives can occur, additional testing is needed to confirm a positive result. If you are a stud owner, you are advised to request a veterinarian’s certificate showing that the visiting bitch has been tested and found free of brucellosis; likewise, the smart bitch owner would want to see the same evidence.
If you want to maintain a breeding kennel, it cannot be stated too strongly that keeping infected dogs is not advised – not only as breeding stock, but they could continue to infect new animals. Once brucellosis has occurred, all animals living together must be screened and the infected ones removed. In addition, follow up tests should be run every three months to identify new cases.
Currently there is NO effective vaccine or treatment for the prevention and cure of brucellosis in dogs. There are long-term antibiotic therapies which can be tried, but the disease can recur when the medications are stopped. Clearly, it is far better to prevent infection in the first place than to try and cure it once it has occurred.
Known pathogens – Mycoplasma
Mycoplasma are organisms which are similar to bacteria, except there is no cell wall present. As a result, they do not respond to certain antibiotics which are able to kill bacteria by breaking down their cell walls. Additionally, they do not grow well in the bacterial culture plates commonly used; they need to be cultured in a special medium, which means the lab would need to be specially directed to look for it.
Mycoplasma have been identified as an agent of infection in dogs, cattle, rats, mice, guinea pigs, chickens, turkeys, and other avian species. They have been found in genitourinary and intestinal tracts, oral cavity, conjunctivae (eyes), respiratory tracts, and other body regions. They may contribute to some extent to the disease syndrome known as kennel cough.
Making treatment and diagnosis even more difficult, mycoplasma live inside mammalian cells, so they are hard to reach. Mycoplasma can cause urinary tract infections. According to Dr. Lewis, prognosis is fairly good if the organisms are sensitive to the antibiotic being used, but it may take long term therapy to eliminate them. Tissue such as the testicles and prostate typically do not readily achieve high antibiotic levels.
Known pathogens – Canine herpesvirus (CHV)
Canine herpesvirus exists all over the world. Only members of the dog family (including dogs, wolves, and coyotes) are known to be susceptible. Typically, canine herpes is a symptomless infection in most animals, although older dogs (males and females) may have a mild runny nose, and bitches may have a mild vaginitis. Transmission occurs by contact between susceptible young puppies (usually during the first three weeks of life) and infected oral-nasal or vaginal secretions of their dam or oral-nasal secretions of other dogs allowed contact with the puppies.
Many veterinarians are of the opinion that canine herpes kills puppies only when they are born to dams suffering their first herpes infections at the time of whelping. Infection can also be transmitted while the puppies are still in utero, and can cause resorption or mummification. Dogs and bitches with weakened immune systems are more vulnerable to acquiring infections with herpes.
Herpes infections usually have a latency period in which the virus may become dormant in ganglions/nervous tissue. The dog might develop protective antibodies that will confer some immunity during the asymptomatic period. Once the animal is subjected to stress that will compromise its immunity, the herpes virus can become an active infection. In any event, the affected dog will carry the virus for life.
There seems to be some disagreement as to how contagious the virus is overall. According to one writer on the internet, the University of Minnesota fertility clinic told her that canine herpes is only a problem during the initial infectious stage. After the dog has been exposed for a period of time, antibodies build up, and the dog is no longer likely to transmit the disease. Several writers reported personal experiences in which after the initial infection and loss of puppies in a litter, subsequent litters were whelped with no noted ill effects. Once the dam has developed an adequate level of antibodies, this can protect her and future puppies.
Unfortunately, there is no vaccine or treatment available for older dogs. The disease is easily diagnosed on autopsy, as typical abnormalities are seen in the lungs, kidneys, adrenal glands, liver, and gastrointestinal tract. The virus is sensitive to lipid solvents (detergents, alcohol, etc.) and to most disinfectants; it is relatively unstable outside the host animal.
Deaths due to canine herpesvirus usually occur in young puppies within about 24 hours of the onset of illness. Dams can be healthy with adequate milk production, and the puppies nurse normally until shortly before their deaths. Early signs of infection include: abrupt cessation of nursing, chilling, painful crying, abdominal distention, loss of coordination, and a yellowish-green diarrhea. Puppies are in agony, and nothing seems to relieve their distress.
The virus does not multiply well at temperatures above 98o F. Puppies up to 21 days old are more vulnerable because their body temperature is below this threshold. For that reason, infected puppies raised in incubators which maintain a body temperature of 100o F may survive, although if they recover, they often develop kidney failure at 8-10 months of age. If the bitch is known to be newly infected prior to whelping, removal by caesarian section and raising them in isolation might prevent puppy deaths. Even so, infections have been found in caesarian-delivered puppies.
Conclusion
Over several years, I have heard of many Cavalier breeders who have lost puppies due to infections with one or more of the causative agents discussed in this article. Usually the cause is discovered after puppies have died. Are you asking to see certificates of brucellosis testing? Should you beef up your pre-breeding and pre-whelping testing programs? Can you afford the extra expense? How can you NOT afford it?
Disclaimer: Your veterinarian is the most qualified person to answer all of the questions you have about your pet’s health. Nothing in this article should be construed as medical advice regarding any individual animal’s condition.