By Kim Everson, DVM
I am exhausted. And demoralized.
Since late Thursday evening I have been caring for a critically ill terrier on intravenous fluids. Up every couple of hours each night for potty breaks, medicating and TLC. During the in-between times watching “Doggie TV”, my closed circuit camera system broadcasting the antics of hospitalized pets to the comfort of my couch (not very stimulating programming…lots of sleeping going on in the clinic!) Just when I thought he was ready to go home on Saturday, he started to relapse.
Denny* is a six-year-old Cairn terrier who presented for vomiting, diarrhea and not eating. Extensive bloodwork and fecal tests all pointed toward acute liver failure. The liver is a very important organ that comes under attack from all sorts of day-to-day insults. Although the liver has hundreds of vital functions, one function is an all around “detoxifier.” Everything that passes through the lips of an animal is dealt with by the liver: bacteria, viruses, toxins, medications. Most of the time anything with potential to harm is effectively neutralized and silently excreted from the body. Sometimes the liver’s defenses are overcome and the animal becomes ill. Luckily the liver also has great regenerative potential, so with some intensive care, elimination of the inciting cause, and time, many of these animals recover fully.
|Electron micrograph of Leptospira bacterium|
Due to his age and vaccine status, Denny was first suspected of having a bacterial infection in his liver called leptospirosis. This organism is shed in the urine of infected wild animals such as racoons or domestic animals like cattle and dogs. The infection is acquired by drinking contaminated water or snuffling around an area where another infected animal has urinated (the bacteria can pass through mucous membranes such as lips, noses and breaks in the skin). Leptospirosis is a zoonotic disease, meaning people can catch it from their infected animal. Some animals become very sick from liver or kidney disease, while others are asymptomatic carriers of the disease, shedding the bacteria wherever they urinate! Yikes! Although leptospirosis is treatable with common antibiotics, if the infection has triggered widespread inflammation in the system the animal may not respond to treatment.
While there is a specific test for leptospirosis, it takes time to run at the outside laboratory and Denny needed treatment immediately. We started him on intravenous fluids to help flush the buildup of liver toxins from his bloodstream, anti-vomiting medications and antibiotics. By Friday evening he was able to keep down water, small amounts of food made for liver failure patients, and oral medications. He was perky and stronger than when he arrived Thursday evening. He even lifted his leg to pee!
On Saturday morning I made preparations for sending Denny home. But by the afternoon, Denny refused to drink and started vomiting again. And his diarrhea returned, a bright orange color signaling continued problems with his liver. Still bright, Denny clearly is not improving enough to go home.
My heart is sinking. It’s not the normal progression of things for uncomplicated leptospirosis. Other differential diagnoses are spinning through my mind as I try to make sense of Denny’s disease. Does Denny, though not old, have a liver tumor? Does he have leptospirosis or other infection complicated by raging hepatitis? Does he have a heretofore asymptomatic congenital liver disease such as a shunt, a condition where blood loaded with nutrients and waste products bypasses the liver processing center? I’m dwelling a lot on this last one because I know more about his genetic background than I do most of my patients. His parents are my patients too. And they are nearly twice his size!
|Portography, a special imaging technique, showing a
large liver shunt. A special dye is injected into the splenic
vein (from right of image) which then travels to the liver.
Here the dye mostly bypasses the liver (middle)
straight back to the heart (left of image).
This size difference worries me because dogs born with liver shunts are generally smaller than their counterparts and may be “poor doers” throughout life. Severely affected animals may show symptoms early on, but some pets find a way to compensate for the disease and may have little to no sign of disease for years. Maybe they do poorly under anesthesia at the time of spaying or neutering. (This is why preanesthetic testing is so important…to catch any early signs of liver problems before anesthesia.) Maybe they are intermittent pukers or have other easily overlooked symptoms of illness throughout life. Maybe as adults they just have some unexplained liver elevations on wellness blood screening and are acting perfectly happy otherwise.
Denny’s owner allowed me to speak with the breeder, who has been able to keep tabs on most of her puppies long after adoption. Turns out Denny was diagnosed with a temporary heart murmur in early puppyhood which later resolved. In addition to being petite, Denny has been intermittently vomiting for years, a medical problem unique to him among his canine family members. She also reports that Denny’s brother died at age 5 from a vague illness involving his liver!
Because liver shunts require specialized imaging or invasive biopsies for definitive diagnosis, the expense of which is outside most families’ reach, we are left with more questions than answers oftentimes. I’m not sure how Denny’s situation will resolve. Time is the nearly magical ingredient in so many of these tough cases. Denny’s owners are committed to giving him a good chance, so we will continue IV fluids and symptomatic medications for now, buying his liver more time to rest, regenerate and recover if possible.