Congenital Heart Disease in a Young Dog

He was less than a year old. His shiny black coat indicated he had been well cared for and was ready for the good life Labrador Retrievers enjoy. But as he lay on the examination it was obvious he was very sick. He had become acutely ill and as he turned toward me his eyes seemed to say, “It’s no use, Doc”.

          With mouth halfway opened he gasped for breath, but there was no sound of rushing air. I could not feel the femoral pulse. Nor, could I hear the heart beat with a stethoscope. These two signs indicated the heart was not adequately pumping blood. However, the electrocardiogram was not unusual. It could not define the type of heart disease, and he was too ill to do chest radiographs that might be instructive. There were sounds of air movement in the lungs, vesicular sounds, detectable with the stethoscope but no rates or creptations. This and his gasping for breath suggested the lungs were filling with fluid escaping from his blood. This is called pulmonary edema. The dog was treated for dilated cardiomyopathy, a common form of heart failure. And, although he was not coughing he was also treated for influenza, a virus infection which can cause pulmonary edema even though heart failure was considered to be a more likely primary cause of his symptoms.

          He died during the night. The necropsy next morning showed his lungs were indeed edematous. Enough so that, it was obvious he had drowned in fluids that escaped into his lungs from blood vessels due to stasis of blood flow that complicated inadequate heart function. The heart disease was not dilated cardiomyopathy. Rather, it was hypertrophic cardiomyopathy; a condition in which heart muscle cells proliferate increasing heart wall thickness. Scar tissue may form further compromising cardiac contraction. Eventually these changes lead to heart failure and death of the victim. Rare in dogs, it is common in cats in which it is thought to be inherited. I was told litter mates of this dog all died suddenly but no diagnosis of cause of their deaths was rendered. These deaths suggest hypertrophic cardiomyopathy in this young litter was inherited. As a rule, therapy of dogs terminally ill with this disease is not effective. Management of the disease is by prevention. Avoid mating of known carriers. 

Treating Puppies with Parvo virus Infection; A Study

Start of the parvo virus season is just around the corner. It extends through fall, winter and spring and is most prevalent in low desert areas such as the Imperial Valley. Affected puppies vomit, and suffer from diarrhea. If neglected, pups can become very dehydrated and death is a common outcome. Some owners treat sick puppies themselves using over-the-counter remedies too often with disastrous results.  Years ago I learned that the drugs used to treat sick puppies were critical. Sometimes when one of the penicillin drugs was used for treatment the puppy would develop a severe Clostridium difficile diarrhea, a very undesirable consequence.

 I did some studies to see what might or might not work. During the 2016 parvo season 61 pups that had tested positive for parvo were treated. They all got the same regimen: a liquid oral prescription for the gastro-intestinal bacteria, a small injection of a broad spectrum-antibiotic for other bacteria in their bodies and an oral antivirus medicine used in people. Puppies were sent home with instructions to return the following day for further treatment. Most of the sick puppies were treated only once, and only one of them died. Perhaps the antivirus medicine was most helpful I am not certain that it was but I continue to rely on it.

Birthing difficulty

Once upon a time, when the world was young, I had a ranch practice in northern Montana.  It was a wonderful time and place for a young man.  Streams were filled with trout, pheasants were in every field, ducks in all the ponds, and every rancher had lovely daughters.  But delivering calves was my livelihood.  Laboring cows taught me a lesson germane to today’s small animal practice.  If a fetus is not positioned in the birth canal it will not be born, nor will the dam strain to deliver it.  The problem is uterine inertia for the uterus will not constrict and start the fetus into the pelvis.  In most cases intravenous administration of calcium will correct the problem.  The uterus can then constrict placing the fetus where it can be expelled normally.  But not always!

            Jessica, a four pound Maltese female had delivered one pup.  Then everything stopped!  For an hour she did not deliver any more pups.  Didn’t even try!  And yet her belly was still distended.  She remained pregnant.  I could palpate a pup out of position in the anterior abdomen.  This seemed to be typical uterine interia so I injected calcium and sent her home.  Often these cases will deliver a pup during the car ride home but not this time, nor during the ensuing hour.  She had to be returned for a caesarian section.  One has to get fetuses out of the abdomen or they will die, start to decompose in the abdomen, and the rotten material will kill the dam.  On reexamination the pup had not been moved.  It was no nearer to the pelvis then when the dog was initially examined.  During surgery I found the wall of the uterus surrounding the remaining pup had ruptured spilling the pup into the abdominal cavity and making it impossible for the pup to be properly positioned.  Why the rupture occurred I don’t know.  Perhaps it was due to incoordination of uterine contractions.  Both pup and mom survived surgery.

            Rarely did I find a cow with uterine rupture and the calf lying free in the abdominal cavity.  If one did surgery in time the cow might live but usually the calf was dead.

"Photo Attributed to S. Fulljames via flickr.com

Diseases of newborn pups

            Weak and stillborn puppies are a common occurrence with Imperial Valley mother dogs.  Owners often claim the cause of death was the mother lying on the young pup.  For the most part this is incorrect.  Most of these pups I have examined were affected by one disease or another.  As such these problems could have been avoided or prevented.

            Several weeks ago a lady brought in a terminally ill three-week-old pup with purulent exudate sealing eyelids of both eyes. She said two litter mates of the pup died shortly after birth.  Cause of this pup’s illness was not readily apparent to me but a scraping of the inflamed conjunctiva showed canine distemper virus in epithelial cells.  I have seen this before: pups being infected with distemper at birth or in the uterus near the termination of pregnancy resulting birth of dead or dying pups.  Had the bitch been given a routine vaccination by a veterinarian a month or so before breeding the chance of her shedding the distemper virus that infected the pups in utero or neonatally would have been greatly reduced.  Note; live virus vaccination very near to conception or during pregnancy can adversely affect the pups before birth.

            There are other diseases causing abortion and neonatal weakness and death that serious dog breeders are advised to prevent if they are seeking healthy litters.  These are venereal diseases transmitted between breeding pairs, canine herpes virus and brucellosis.  Once infected with these diseases dogs can have breeding problems for years.  By having prospective mates tested by a veterinarian a month or so prior to breeding infected brood stock can be identified and avoided.  Thus, valuable breeding stock should be mated only with animals that have tested negative for canine herpes virus and brucellosis.