Dear Dr. Forsythe: I was devastated to find out that my new eight-week-old Chihuahua has a very loud heart murmur when we brought her in for her first puppy check. We were told that there was a “machinery murmur” and that there was a good chance she had a PDA. Can you tell me a little more about this? Thanks.
Devastated owner,
Sonoma
Dear Owner: Let me start by telling you how sorry I am that your little puppy has this serious problem. I know this is a difficult time, and all these decisions you need to make now are very stressful. “Machinery murmurs” are very pronounced murmurs that sound like a rumble through the stethoscope. The sound is caused from a “Patent Ductus Arteriosis” which is a prenatal vessel that normally closes when a puppy is born and begins breathing room air. Occasionally, if this blood vessel beside the heart fails to collapse down at birth, this causes a disruption in the blood flow in the puppy. The abnormal blood flow causes such a loud sound that the murmur is also referred to as a “tennis shoes in the dryer” murmur. X-rays usually an enlarged heart and a cardiac ultrasound can confirm the diagnosis.
When a diagnosis of PDA is confirmed, you have a big decision to make as the pet’s guardian. The pup will almost certainly need open thoracic surgery to correct the shunted vessel in his chest in order to live a healthy life. This operation has risk and is costly, but without it, his heart condition will deteriorate. Some people who are faced with this dilemma decide to return the puppy to the breeder and get a healthy litter mate. Whatever you decide, I know this is a heart-wrenching time, and my best thoughts are with you.
Dr. F.
Dear Dr. Forsythe: I saw a black widow spider by the trash in my side yard the other day. Will this spider kill a dog? Please let me know. I shudder at the thought. Thanks.
Spider hater
Dear Spider hater: It sounds like you know how to recognize the black widow, which is important! They are known as dangerous, poisonous spiders, known for the hour glass marking on the globe-like shiny abdomen, on the underside. The female is more dangerous because the male probably can’t penetrate skin. Immature females may have a pattern of red brown and beige on the top aspect of the abdomen, and these spiders are often found in dumps, outhouses and trash piles.
The initial lesion is often painless, so if your pet is bitten, he probably won’t yelp out. The toxin is a neurotoxin, so after the bite, a localized numbness occurs early, replaced by increasing muscle pain, muscle twitching, and then cramping of large muscle areas (the chest, abdomen, and back). As time passes, the abdomen becomes rigid, but not tender (unlike in humans, who describe the sensation of black widow spider bite as a pain resembling appendicitis). Dogs show initial increased activity then after 10 or 20 hours develop paralysis. In cats, the paralytic signs appear earlier and become quite dramatic. Treatment consists of aggressive supportive care. Antivenin exists, and works if given early. If all this info on this infamous spider creeps you out, you are not alone!
Dr. F.
We welcome your feedback. For general feedback or to contact one of our columnists, please visit the Columns page.
