Leptospirosis

General Information

Leptospirosis is an illness caused by bacteria called leptospira. These bacteria are shed in the urine of animals carrying the disease. When a healthy pet drinks from puddles or still water that has been contaminated with the bacteria, they may develop leptospirosis. It generally takes about 10 – 14 days for signs to develop. In the early stages, dogs act depressed, inappetant, or stiff. They may run fevers, and may have upset stomachs. As the illness progresses, they develp severe infections in their liver and kidneys. While the disease is treatable in the early stages, it can be fatal if it leads to kidney or liver failure.

Diagnosis of leptospirosis is difficult because the test for it can take up to a week to get results, and the results are often misleading. Not all dogs that are sick with the leptospira bacteria test positive for the disease. As a result, medical diagnosis is based on signs, fever, and blood results consistent with a liver and/or kidney infection.

 

Important Points in Treatment

 

Dogs showing signs of Leptospirosis need to be hospitalized for intensive care treatment. During their hospital stay, we monitor blood tests for liver and kidney function to judge the effectiveness of the treatment. Some dogs that are very ill may need to be transferred to a 24 hour care facility. Treatment may involve several days to weeks in the hospital, followed by long term antibiotics to rid them of the bacteria. Leptospirosis is contagious, so dogs stay in our isolation ward during their hospital stay. Owners of dogs with Leptospirosis should contact their physician if they are concerned about their family’s risks.

 

Prevention

There is a vaccine to help protect dogs from catching Leptospirosis. The yearly distemper vaccine includes protection against four of the eight bacteria that cause the disease.  However, because the vaccine is based on a protein, dogs can have allergic reactions to the  vaccination. Most reactions are mild, just some vomiting and a mild fever. Some can be more severe, causing hives, facial swelling, and anaphylaxis. Dogs at highest risk for catching leptospirosis, are dogs that swim, or spend a lot of time outside. Even city dogs are at risk if they happen to drink from a puddle contaminated by an infected rodents. Leptospirosis is seen more during rainy weather, probably because there are more puddles, and mud pools for dogs to drink from.

Notify the Doctor if Any of the Following Occur:

• Your pet refuses to eat.

• Your pet has diarrhea or vomiting, or seems to have abdominal pain.

• Your pet is acting listless or stiff and achey.

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Lyme Disease

 Lyme Disease is caused by a spirochete bacteria called Borrelia. It is transmitted to dogs through the bite of a tick. Once in the blood stream, it is carried to many parts of the body, where it can cause inflammation of the joints, kidneys, heart tissue and tissue of the central nervous system. It was first thought that only a few types of ticks could transmit this disease, but now it appears that several common species may be involved. In order for the tick to transmit the disease, it must feed on the host’s blood for 48 hours. If the tick is killed or removed before than, it is unlikely to have been able to successfully transmit Lyme disease to your pet.

Lyme disease can also occur in humans, but it is NOT contagious from an infected pet. The only way a person can get Lyme is to be bitten by an infected tick. If your pet tests positive for Lyme disease, consult your physician if you have any further concerns.

Clinical Signs

Most dogs affected with Lyme disease are taken to a veterinarian because they seem to be experiencing generalized pain and have stopped eating. Affected dogs have been described as if they were "walking on eggshells." Often these animals have high fevers, won’t eat, and are acting stiff and lethargic. The characteristic rash seen with people is usually missed in pets because of their fur coats. Later in the disease, dogs may also become lame. This painful lameness often appears suddenly and may shift from one leg to another. If untreated, it may eventually disappear, only to recur weeks or months later. In the more chronic stages, kidney disease, heart disease, chronic inflammatory arthritis, and even seizures may develop.

Diagnosis

Diagnosis is based on clinical signs, response to treatment, and levels of antibody to the Lyme bacteria in the bloodstream. A quick and simple blood test can determine if your dog has been exposed to the bacteria that causes Lyme disease. While a positive test does not prove a dog has Lyme disease, a negative test does mean your dog does not. A dog that test positive, has typical clinical signs, and responds well to antibiotics, is a dog that has Lyme disease. Complications of Lyme disease such as immune mediated arthritis, kidney failure, or heart disease, can be diagnosed through blood tests, radiographs, and ultrasounds.

Treatment

Because the Lyme spirochete is a bacterium, it can be controlled by antibiotics. However, a lengthy course of treatment is necessary to completely eradicate the organism. The initial antibiotic selected to treat an infected pet may not be effective against the disease, especially if the infection is long-standing. In this situation, a switch to another antibiotic is often effective. Occasionally, the initial infection will recur, or the pet will become reinfected after being bitten by another infected tick. Antibiotics can be prescribed as needed based on your veterinarian’s recommendations.

Prevention

Lyme prevention is based on protecting your pet from ticks, and by vaccinating high-risk animals against the Lyme bacteria. High-risk dogs are those that are outdoors in the woods or grasses, especially in shore areas, and on the Connecticut line. Any place that has deer is an area likely to have Lyme. To prevent ticks from transmitting the disease, a topical medication like Frontline or Preventic collar can be used. Checking your dog regularly for ticks and removing them as soon as possible is also an excellent means of Lyme prevention. The vaccine available can be given after 12 weeks of age. It is only about 85% effective, and like all vaccines can have potential side effects. Your veterinarian can recommend the best means of prevention based on your pet’s special circumstances.

 

Signs to Watch For

• Decreased appetite

• Stiffness

• Fever, lethargy

• ADR – “ain’t doing right” in a high risk dog

Anaplasma

THE PET HEALTH LIBRARY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

Ehrlichia Infection in Dogs

 

What are Ehrlichia?

Ehrlichia, named for the Dr. Ehrlich who first described them, are a type of bacteria that infect and live within the white blood cells of their hosts. Different types of Ehrlichia live in different types of white blood cells. Hosts can be human, pet, or wild animals. Ehrlichia are spread from host to host by tick bites and their intracellular location makes them difficult to remove as most antibiotics do not penetrate to the inside of cells.

The Crazy Ehrlichia Name Game

Ehrlichia were originally grouped according to the type of white blood cell they attacked. The granulocytic line of white blood cells, used by the body in attacking more acute inflammatory invaders, has a lobulated nucleus and characteristic blood cell appearance. The monocytic line, used by the body for chronic forms of inflammation, has a more rounded nucleus. By finding Ehrlichia inside certain types of white blood cells, one could get a better idea for which type of Ehrlichia one was seeing. Or so we foolishly thought.

When Dogs get Sick
There are three phases of illness with Ehrlichiosis: acute, subclinical, and chronic.

• ACUTE PHASE: This is generally a mild phase and occurs 1 to 3 weeks after the host is bitten by the tick. The Ehrlichia organism is replicated in this time period and attaching to white blood cell membranes. During this time the platelet count will drop and an immune-mediated platelet destruction will occur. The dog will be listless, off food, and may have enlarged lymph nodes. There may be fever as well but rarely does this phase kill a dog. Most dogs clear the organism if they are treated in this stage but those that do not receive adequate treatment will go on to the next phase.
 
• SUBCLINICAL PHASE: In this phase, the dog appears normal. The organism has sequestered in the spleen and is essentially hiding out there. Dogs can stay in this phase for months or even years. The only hint that Ehrlichia is hiding is a somewhat reduced platelet count and/or elevated globulin level on a blood test. The blood protein level on a lab report is divided into albumin (an important carrier protein) and globulins (every other blood protein including antibodies.) Long-term stimulation of the immune system will elevate globulins.
 
• CHRONIC PHASE: In this phase the dog gets sick again. Up to 60% of dogs infected with Ehrlichia canis will have abnormal bleeding due to reduced platelets numbers. Deep inflammation in the eyes called uveitis may occur as a result of the long-term immune stimulation. Neurologic effects may also be seen. Glomerulonephritis, which results in serious urinary protein loss, can also occur. Increased globulin levels are almost always seen in this stage, and albumin is often low. Most dogs in the U.S. do not show the full pancytopenia (literally reduction in all blood cell lines).

Infections with Ehrlichia lewinii tend to produce arthritis in addition to the above scenario.

How the Diagnosis is Made

Diagnosis does not rest on a single test but instead on a collection of results.  The first step is to find a constellation of typical findings:

• A dog with fever, enlarged lymph nodes, bleeding, or arthritis in multiple joints.
• Low platelet numbers, high globulin levels, and mild anemia on blood testing.

When Ehrlichiosis is suspected, a blood test for antibodies against Ehrlichia organisms can be ordered. A positive test indicates that the dog has been exposed to Ehrlichia and does not imply active current infection necessarily. A negative titer does not fully rule out Ehrlichia, either, as a very sick patient will be too sick to produce antibodies and an early case may not yet have started to produce antibodies.

The ELISA test is included in a new in-house test kit from IDEXX labs (the snap 4DX test) that also includes a Lyme disease test and a heartworm test. The 4DX test is geared specifically to detect antibodies against Ehrlichia canis. It is not entirely clear if antibodies against other types of Ehrlichia will be similar enough to be detected by either the IFA or ELISA tests reliably. It takes 6 to 9 months after infection for titers to begin to drop.

Treatment

Despite being one of the oldest antibiotics in use, tetracycline is probably the most effective against Ehrlichia (and any other intracellular blood parasite for that matter). Doxycycline, a more modern derivative, has a more convenient dosing schedule and has become more popular. Expect at least a month of treatment to be needed. Response is initially rapid (improvement is notable in the first few days).

If immune-mediated secondary reactions to the Ehrlichia are a problem (such as immune-mediated arthritis, or immune-mediated platelet loss) corticosteroids such as prednisone can be used to palliate the situation while the antibiotics are starting to work.

After infection, it is possible to become re-infected; immunity is not lasting after a previous infection.

Date Published: 8/15/2005 11:02:00 AM
Date Reviewed/Revised: 5/9/2009

 

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