Leptospirosis alert!

In late July, my Cairn Terrier Lizzie was diagnosed with very sudden and complete kidney failure.  She went from feeling well on a Friday and Saturday morning, to being picky with her dinner Saturday, to vomiting Sunday.  Alarmed, I worked her up at the hospital first thing Monday morning and found that she was in kidney failure.  We started IV fluids and supportive therapy immediately and ran more blood tests.  By the end of the week, we knew the cause: leptospirosis.

What is leptospirosis and what are the signs?

Leptospirosis is a bacterial disease that affects humans and animals. And it's a very serious one.  The incubation period - the time between which an individual picks up the disease and shows the symptoms - is commonly about 10 days (range, 2 days to 4 weeks). Symptoms can include flu-like illness (high fever, headache, chills, muscle aches), jaundice, conjunctivitis, abdominal pain, vomiting, diarrhea, and sometimes a rash. In severe cases, the patient may progress to renal failure, liver failure, respiratory distress, or meningitis.   And in dogs, signs common with complete kidney failure are often the only symptoms noted: vomiting, depression, and refusing to eat.  That's what happened to my Lizzie.

How does a pet or a person get it?

Outbreaks are most frequently associated with exposure to water contaminated with the urine of infected animals such as cattle, pigs, horses, dogs, rodents, and other wildlife. Raccoons are big carriers in the Midwest.  Humans and animals can become infected by swallowing contaminated water or by having contaminated water contact mucous membranes or broken skin - or even intact skin and paws. Certain occupations (farmers, veterinarians, sewage workers, etc.) put persons at increased risk of exposure to leptospirosis.  But those who work or play with their dogs in ponds, lakes, streams, and other waterways are very much at risk, also - as are their pets.

The largest human leptospirosis outbreak in the continental U. S. occurred in a group of persons participating in competitive swimming events in the Midwest in 1998 where 110 cases were identified among 775 exposed persons. That is, until this year - when the final data is collected, this will likely be a very bad year, too.   That's because there is a direct association between the amount of rainfall and the incidence of leptospirosis.

Dr. Michael P. Ward, of Purdue University's School of Veterinary Medicine, is a pathobiologist who has been tracking lepto cases for years.  He looked at the cases of hundreds of dogs diagnosed with leptospirosis at 22 veterinary teaching hospitals over a 15 year time frame. Most cases were diagnosed between August and November during each year of the study. A HUGE correlation was detected between the number of cases of leptospirosis diagnosed and the average rainfall recorded 3-months prior to diagnosis.   In his study he concluded that leptospirosis has a seasonal distribution (late summer to fall), and that rainfall can be used to predict the occurrence of leptospirosis.

A big challenge with identifying who has leptospirosis and who doesn't is the many types of leptospirosis.  More than 200 Leptospira serovars - variations of leptospirosis - have been identified.  Not all can be identified by testing, either.  In fact, there are no tests for many types of leptospirosis.    Dr. George Moore of Purdue University collected data from over 1800 veterinary hospitals across the USA, to look at what types of leptospirosis were most common in infected dogs and how common it was.  He confirmed that the incidence of leptospirosis in the Midwest was exceptionally high.  And specifically in Illinois, the risk began increasing significantly in 2004.

Dogs in suburban or rural environments have been shown to be at increased risk of leptospirosis, because of greater likelihood of contact with wildlife habitats.  And in our area, the number of parks and forest preserves with lakes, streams, and ponds makes the risk even greater.  In areas that flood and areas with poor water drainage, leptospirosis can run rampant - and it does.  This year’s record rainfalls and severe flooding have tremendously raised the risk for leptospirosis infection.  Access to areas where people feed wildlife such as raccoons, also raises the risk of leptospirosis infection for people and pets.

My Lizzie goes nowhere besides her fenced backyard and the small grassy strip behind the hospital.  Both areas are always bone-dry - or were, before this summer's rains.  We can only assume that she contracted this deadly disease through contact with an infected animal’s urine - urine that wouldn't have dried up almost immediately, as it would have during a normal dry summer.  Instead, all the rain this summer would have permitted the leptospirosis organisms in the urine to spread into the water-saturated soil.  And now, my Lizzie is in kidney failure.

What happens to dogs who get leptospirosis?

Some dogs live with proper treatment, but it's a sad fact that up to 20% of them will not survive.  Treatment is very expensive - Lizzie is now in her third week of IV fluid therapy, twice daily antibiotics and medications for nausea that cost $40 a pill, and she still has to be tube-fed some of the time.  She still requires 18-hour-a-day nursing care.  It is agonizing to see a pet wasting away from leptospirosis.

What do I do if I think my pet has been exposed to leptospirosis?

A quick and simple blood test can help you and your veterinarian decide how to proceed.  Pets who test positive to leptospirosis should be started on appropriate antibiotic therapy immediately.  All dogs in the household should be tested, even dogs who are largely inside.  My Lizzie was not an outside dog; in fact, she comes to work with me every day, all day!

How can I keep my pet from getting leptospirosis?

There are no sure preventatives.  Vaccinating for this disease is a good start.  While vaccinations do not protect against all types of leptospirosis, they do protect against the most common kinds that a dog is likely to get.  It is also important - make that CRITICAL - to keep your pet out of ponds, lakes, and streams for the rest of this year and probably next year as well.  All the rainfall we've had has tremendously increased the risk of leptospirosis in all water areas.

What’s going to happen to Lizzie?

All of us at the hospital wish we knew.  She’s very sick and still in complete kidney failure.  She won’t eat anything except roasted chicken, which isn’t good for her kidneys, and she’s sick of having medicine administered every few hours.  She hates getting fluids all the time, too.  She’s gone from being a happy, active, fun-loving and rambunctious Cairn terrier to a bone-thin little dog who barely has the strength to struggle when it’s time for more medication.  But she still gives kisses, and she still tries to play with her ball on occasion, and we’re giving her every chance there is.

For more about Lizzie, visit her column, “Lizzie Says...” on the hospital website.