This week, I’d like to cover a slightly less extensive topic than dental care. Anyone who has read through all of the posts on dental health has my thanks! I could easily have spent several more posts talking about dentistry and current treatments, but I think we should change gears for a while.
One of the most controversial topics in health care is vaccination. There is a tremendous amount of data out there, especially on the internet. There is also a heated disagreement between allopathic (traditional/Western) and naturopathic/homeopathic supporters about whether vaccines are a benefit or are detrimental to the health of humans and animals.
I really, really, really do NOT want to get into a debate about vaccinations at this point in the blog. What I’m going to talk about today will be purely to inform readers about a disease that concerns me with regard to the health of our pets. Yes, there is a vaccine for this disease. I encourage anyone who reads this post to discuss the vaccine with your veterinarian directly. Anyone who would like more information is welcome to contact me through the blog
Leptospires are spiral bacteria (called spirochetes). The photo above shows a large number of these long, corkscrew shaped organisms. There are over 200 sub-types of lepto (called serovars). Lepto is found worldwide. It survives very well in warm, moist environments. The bacteria can live in standing water for a very long time. Even moist soil can support lepto for up to 180 days. Areas like ours, with many lakes, streams, and swamps, are a great place for lepto to survive in the warmer months.
Animals and people can be infected by lepto, which makes leptospirosis a zoonotic disease. The bacteria enters through the mucous membranes in the eyes, mouth, and nose. It can enter cuts or other open wounds and can be contracted by drinking contaminated water. In our area, the primary carriers for lepto are wild animals such as opossums, raccoons, and rodents. Dogs, horses, cattle, sheep, goats and pigs are also common carriers. Many of these animals will show no signs of carrying lepto. They shed the bacteria in their urine, which is how it enters the environment. Coming into contact with contaminated water or urine/blood from an infected animal can transmit the disease. Cats seem to have a natural resistance to lepto and are not considered a major carrier.
People contract lepto by coming into contact with a contaminated environment or urine from an animal carrying the lepto bacteria. Standing water in swamps, puddles, ditches, etc. are primary places that lepto can be found. The bacteria need to enter the body through open cuts, eyes, mouth, or other mucous membranes.
According to the CDC, approximately 100-200 human lepto cases are reported each year in the US. About 50% of those occur in Hawaii.
Animals and people that contract lepto will often have flu-like symptoms such as fever, chills, shivering, and lethargy. Liver and/or kidney failure can also occur. Signs may seem like liver failure (yellow skin/mucous membranes, vomiting, not eating, lethargic); or kidney failure (vomiting, not eating, lethargic, dehydrated). These signs can mimic many other illnesses, which makes it hard to distinguish lepto as the cause. Some animals will drink excessive amounts of water because of kidney failure that results from infection. Urine production could be excessive or far less than normal, depending on the degree of damage to the kidneys. The picture below is jaundice in the oral mucous membranes of a dog.
Lepto is difficult to diagnose. There are special blood tests that measure the body’s response to the bacteria (antibody levels). Unfortunately, many animals do not have high antibody levels when they first get sick. Many times, another blood sample taken after an animal recovers is needed for a solid diagnosis. Most veterinarians treat for lepto based on the risk factors of the dog, the examination findings, and the result of routine blood tests.
Animals must first be treated for the initial period of infection. Then, they have to be treated for about 30 more days to make sure they are not carrying lepto and shedding it into the environment. Initial treatment includes hospitalization for IV fluids and antibiotics (usually a penicillin-type). Often, intensive care is needed for animals that are suffering from kidney or liver failure. The degree of damage to the liver and kidneys varies. Some animals have minimal damage from which they fully recover. Others suffer permanent damage. Some animals will die from lepto infection. Early, aggressive treatment with fluids and antibiotics is essential for the best chances of recovery. Once an animal recovers from the initial infection, the carrier state is eliminated by giving the antibiotic doxycycline for about 30 days.
Preventing lepto from being in the environment is virtually impossible. There is a vaccine available for dogs that contains the 4 top serovars that cause infections in dogs. These four strains are icterohemorrhagiae, canicola, gryppotyphosa, and pomona. The vaccine requires an initial series of 2 injections given approximately 3-4 weeks apart. The vaccine is boostered annually. The vaccine can not protect a dog from strains that aren’t included in the vaccine. Therefore, a dog can be infected by another strain if it’s encountered in the environment. There have been cases of other strains in our area. The vaccine may not prevent an animal from shedding the bacteria, but it does protect a pet from developing full-blown illness from lepto.
Lepto has been reported to be found in 37.8% of dogs in cities and 18.7% of dogs in suburban areas. (Tilley and Smith. The 5-minute Veterinary Consult, 3rd ed.)
I firmly believe that leptospirosis is a disease that we should be concerned about in our area.