Lyme disease is one of the most common tick-transmitted diseases in the world but not exactly the easiest to diagnose since it only causes symptoms in five to 10 percent of affected dogs or cats. It is caused by a spirochete (bacteria) species of the Borrelia burgdorferi (B. burgdorferii) group.
When infection leads to disease in dogs or cats, the pet owner may notice a recurrent lameness de to inflammation of the joints. There may also be a lack of appetite and depression. More serious complications include damage to the kidneys, and rarely, heart or nervous system disease.
Many dogs or cats that develop Lyme disease have recurrent lameness due to inflammation of the joints. Sometimes the lameness lasts for only three to four days but recurs days to weeks later, either in the same leg or in other legs. This is known as “shifting-leg lameness.” One or more joints may be swollen, warm, and painful.
Some animals may also develop kidney problems. Lyme disease sometimes leads to glomerulonephritis inflammation (a type of inflammation of the kidneys) and accompanying dysfunction of the kidney’s glomeruli (essentially, a blood filter). Eventually, kidney failure may set in as the dog begins to exhibit such signs as vomiting, diarrhea, lack of appetite, weight loss, increased urination and thirst, and abnormal fluid buildups.
Other symptoms associated with Lyme disease in dogs and cats include:
- Stiff walk with an arched back
- Sensitivity to touch
- Difficulty breathing
- Superficial lymph nodes close to the site of the infecting tick bite may be swollen
Because so many dogs or cats do not develop symptoms after infection with B. burgdorferi, the diagnosis of Lyme disease must be made on a combination of factors, including history (especially exposure to ticks), clinical signs, finding antibodies to B. burgdorferi bacteria, and a quick response to treatment with antibiotics.
An antibody test is not enough to make a diagnosis on its own, because not all animals that are exposed to B. burgdorferi get sick, and the antibodies can persist in the blood for a long time after exposure.
Your veterinarian may run some combination of blood chemistry tests, a complete blood cell count, a urinalysis, fecal examinations, X-rays, and tests specific to diagnosing Lyme disease (e.g., serology). Fluid from the affected joints may also be drawn for analysis.
There are many causes for arthritis, and your veterinarian will focus on differentiating arthritis initiated by Lyme disease from other inflammatory arthritic disorders, such as trauma, degenerative joint disease, or osteochondrosis dissecans (a condition found in large, fast growing breeds of puppies).
Immune-mediated diseases will also be considered as a possible cause of the symptoms. An X-ray of the painful joints will allow your doctor to examine the bones for abnormalitie
Other diagnostic tests such as blood tests, urine tests, x-rays, and sampling of joint fluid, may be done as well to check for more serious effects of Lyme disease such as kidney disease, and to rule out other conditions that can cause similar signs and symptoms.
If the diagnosis is Lyme disease, your pet maybe treated as an outpatient unless their condition is unstable (e.g., severe kidney disease). Antibiotics most likely will be prescribed for the treatment of the Lyme disease. The recommended treatment length is usually four weeks, but longer courses may be necessary in some cases.
If there are more serious issues that might be secondary to Lyme disease, such as kidney disease, a longer course of antibiotics along with additional medications is usually necessary. Your veterinarian may also prescribe an anti-inflammatory (pain reliever) if your pet is especially uncomfortable.
Unfortunately, antibiotic treatment though in many cases is successful, does not always completely eliminate infection with B. burgdorferi bacteria. Symptoms may resolve but then return at a later date, and the development of kidney disease in the future is always a worry.
As with many other illnesses, the best plan of attack is not to become affected. Tick control is extremely important for the prevention of Lyme disease (and other diseases that can be transmitted by ticks).
Check outdoor cats and dogs daily for ticks and remove them as soon as possible, since ticks must feed for at least 12 hours (possibly 24-48 hours) before transmitting the bacteria causing Lyme disease.
Be careful handling ticks, as they can infect people, too.
For more advice on how to keep your dog, cat and yard tick free consult your veterinarian.