[Betsy Iole]

From
 
Recent Advances in Canine Infectious Diseases, Carmichael L. (Ed.)
International Veterinary Information Service, Ithaca NY (www.ivis.org), 2004; A0102.0899


Neonatal Viral Infections of Pups: Canine Herpesvirus and Minute Virus of Canines Canine Parvovirus-1  (Last Updated: 19-Aug-2004 )

L. Carmichael

Experience has taught many breeders who had accepted neonatal pup death rates of 15 - 25% that simple management could greatly reduce mortality. Examination of bitches for general and reproductive health before and after whelping, supplemental or tube feeding of pups that fail to suckle and providing warmth, which is vital to pups during the first 2 weeks of life since temperature regulation is poor are important factors. Supplemental radiant heat to raise the environmental temperature to ~85ºF, and a relative humidity of ~60% during the first week of life, especially if pups are orphaned, has reduced mortality rates in several kennels from ~25% to <10%. More than 75% of pup deaths occur prior to the 3d week of life, the vast majority occurring during the first week due to physiologic, congenital/genetic, behavioral bitch, environmental conditions or bacterial septicemias. Unfortunately, there is a discouraging lack of knowledge of the true causes of most neonatal illnesses or death and little research is being done on this important subject.

Infectious diseases are believed to comprise only a very small portion of pup deaths up to the time of weaning; however, two viral infections have been described that affect pups during the first 2 - 5 weeks of life: Canine herpesvirus is widely recognized; minute virus of canines CPV-1 has only recently been recognized as a pathogen. Canine adenovirus-1, distemper and canine coronavirus, as well as several bacterial infections, also may cause puppy deaths.

Canine Herpes Virus

Disease caused by CHV is generally fatal in neonatal pups who lack immunity derived from their dams. Neonatal pups may be infected during passage through an infected dam's birth canal or, more commonly, by contact with oronasal secretions of the dam or other dogs in a kennel. Infected littermates, or neighboring dogs who are shedding virus, also serve as sources of infection. Deaths of 1 to 4 week old pups are most common. Pups rarely die if they are 2 - 3 weeks old at the time of exposure. The duration of illness in newborn pups is 1 to 3 days. Signs consist of anorexia, dyspnea, pain upon abdominal palpation, incoordination and, often, soft, yellow-green feces. There may be a serous, or hemorrhagic nasal discharge. Petechia are common on the mucous membranes. Rectal temperatures are not elevated. Thrombocytopenia has been reported in dying pups...

Vaccines
An inactivated, subunit vaccine (Eurican Herpes 205, Merial Animal Health) has been available in Europe since 2003. The vaccine is specifically indicated for bitches during pregnancy. It consists of purified CHV glycoproteins in a mineral oil solvent. It has been shown to have few undesirable effects; nevertheless, transient edema may occur at the injection sites. Reactions usually regress within 1 week. Eurican Herpes 205 was shown to provide good immunity to newborn pups after 2 injections had been administered to their dams. Vaccine should be given to dams during heat or early pregnancy and, again, 1 to 2 weeks before the expected date of whelping...

Treatment
Antiviral drugs have been generally unsuccessful, although some success has been reported with pups in exposed litters given vidarabine before the onset of symptoms. Antiviral treatment may spare life, but residual damage to the CNS and heart may occur. There has been success in preventing infection in neonatal puppies prior to exposure to CHV during kennel outbreaks by injecting 1 - 2 ml of immune sera from affected dams. Such treatment is effective only if virus has not generalized. Once illness develops in pups, serum treatment is ineffective. Immune serum is not available commercially.

Minute Virus of Canines (Canine Parvovirus-1)

Most cases have been pups at necropsy who died suddenly between 1 and 3 weeks of age with respiratory distress and/or variably severe diarrhea. In litters where dead pups were observed, littermates that survived had vague signs, e.g., anorexia, failure to nurse or eat and mild respiratory illness or diarrhea. Such pups recovered within a few days. Transplacental infections with fetal deaths and abortion have been demonstrated experimentally; therefore, CPV-1 may be a cause of abortions or "failures to conceive". The natural route of infection is believed to be by oral exposure, as with the more pathogenic canine parvovirus type 2...

The principal clinical signs reported are those of "fading pups" - lethargy, loose stools or diarrhea, respiratory distress (dyspnoea), and sudden death in newborn pups attributed to viral myocarditis.

[ August 20, 2004, 03:09 PM: Message edited by: Betsy Iole ]

 

[Carolyn Young]

In a litter of 10 last year we lost a very small pup the first day and attributed it to being too small/undeveloped to survive. Then another started to go and we rationalized it. He was also small. When the 3rd started to go at about the 3rd day we rushed him into the vet for an evaluation. He was almost gone and the vet said it was all the signs of canine herpes virus. The vet has only been practicing a few years and my regular vet who owns the clinic was not available. The young vet told me to go home and prepare to lose the whole litter.

Any bitch we plan to breed has a complete health workup including genetic testing before any breeding is done, so I don't know what could have been done with her that we didn't do.

Having nothing to lose and no knowledge of how we might handle the situation we decided that a virus won't live above about 100 degrees F and that if we raised the temperature above that we might have a chance. So we placed the 7 remaining pups in a controlled environment (moisture and 102-103 degrees). Within 4 hours the crying had stopped and the pups began to be more active. By the time they had been in these conditions for 7 hours the pups appeared to be normal. Gradually, over 2 days we took the temperature back to about 95 degrees and then by the end of the week down to 90 degrees.

The 7 remaining pups developed normally and are now 9 months old. They have had no apparent after effects.

We may have been just plain lucky, or we may have been logical. I don't know.

 

[Betsy Iole]

That's very interesting, Carolyn. I've run across some other descriptions of a similar approach. What sort of set-up did you use to maintain the high temps and humidity?

I haven't had a chance to check into whether the CHV vaccine is available in the US yet. Would be interested to hear whether anyone else has used it.

[ August 23, 2004, 09:56 AM: Message edited by: Betsy Iole ]

 

[Carolyn Young]

The setup was pretty basic. When we built our house we created a space in the laundry room for the whelping box and a sleeping bag in addition to the typical laundry room stuff. Above the whelping box area are several heat lamps that can be turned on individually to control the heat below them. To introduce moisture we put containers of water in the whelping box, but we find that running a load of laundry is equally effective. As I said, this isn't rocket science, but it apparently worked.

Back in the early '80's we had a litter that may have had the same thing. Seven pups of 9 died within a period of 24 hours on a weekend when I couldn't get to my repro specialist, Dr. Aura McConnell, but when I finally did she told me what kills a virus and what I could do about it. We'd never had the problem again until last year.

At the time we had the first problem I was working in aerospace designing expert systems (artificial intelligence) and I approached her about designing an expert system to diagnose breeding and fertility problems. The plan originally was to publish it in a book, but gradually morphed into a website. Canine herpes virus was one of the things we addressed, and this method was included. Unfortunately, Aura passed away a few years ago and all that knowledge is sitting on my shelf. We have saved the lives of several dogs over the years as a result of the information contained.

BTW -- when my regular vet returned he agreed that what I did was perfectly appropriate and was not surprised that we saved the rest of the litter.

 

[bubbad]

Very interesting! I've never had a puppy die but have helped to deliver a litter where the Dam died 24 hours after birthing 8 viable pups,she had retained puppies even after a huge dose of oxytocin and had been palpated by the Vet.Vet did not do x-rays because she couldn't feel anything more but next morning Dam delivered one desolving puppy,I felt she had at least 3 more in there. Vet operated but she died on the table. Next-Keep 8 puppies alive.Found surogate Dam but overnight a thriving puppy died.We took puppies back and started to bottle feed.The breeder and I had not dealt with this before,we lost 4 of the eight puppies probably due to fading puppy syndrome but we'll never be sure. I do know not to feed a chilled puppy but I've never had experience with viruses,I don't wish anyone's puppies any harm but it is good to know there is somewhere I can find this info. Thank You