National Vizsla Association -- Articles Ticks

National Vizsla Association

Ticks and Related Diseases

This article was written by Marion Coffman.

Ticks are bloodsucking parasites that exist virtually wherever animals live. Ticks transmit a large number and variety of infectious diseases including Heptaozoonosis, Rocky Mountain Spotted Fever, Lyme disease, Ehrlichia, Babesiosis, Tick paralysis and Tularemia.

If you live in a wooded area where ticks are an everyday problem, careful tick control is necessary. Dog kennels, barns, and homes will require periodic treatment with chemicals to control the free-living stages of the different varieties of ticks. The house and yard should be treated every 2 weeks during the summer, or even year-round in the warmer climates where the brown dog tick is an on-going problem.

Ticks may be found anywhere on your dog's body, but the usual place is around the neck, ears and between the toes, causing inflammation and irritation from their bites. A male tick or an unfed female is flat and brown. The blood-engorged females are flat, large and gray. A feeding female will usually be found with a small male attached under her. It is not a good idea to use your fingers to pull a tick off your dog. If the tick bursts during removal, you can be exposed to Rocky Mountain Spotted Fever or Tick paralysis. Instead, grasp the tick with tweezers and pull gently and slowly until it lets go.

Tick Paralysis

Ticks secrete a toxin that affects the nervous system and actually causes paralysis in a dog. The first sign in the dog is uncoordination, as he becomes unable to move his hind legs. The paralysis slowly moves upward, involving the front legs. In a heavy infestation the paralysis can involve the dog's respiratory centers in the brain, causing death. The dog will have a normal temperature and show few signs of illness except he will be uncoordinated and unable to function. The incubation period is 5-7 days and paralysis can peak within a few hours; timely removal of any ticks can prevent tick paralysis from spreading to the nervous system and recovery is rapid and complete if caught in time.

Diagnosis of tick paralysis is based on the presence of ticks and the sudden appearance of the paralysis, plus the rapid recovery upon removal of the ticks.

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever is the most common tick-carried infection in humans in the country. The disease is not transmitted from dogs to humans but both can catch it

from infected ticks. Or you can catch it when coming into contact with fluids from an engorged tick while removing it from your pet. For that reason careful handling of the tick when taking it off your dog is necessary.

Early signs in your pet: high fever, lack of appetite, depression, abdominal pain, coughing, and edema of the face and extremities. Additional signs include nose bleeds, blood in the feces and urine, enlarged lymph glands, hemorrhages of the mucous membranes and retinas, vomiting and diarrhea. He may also show signs of brain damage, including staggering and convulsions. Blood tests may be needed for confirmation and immediate supportive treatment for dehydration and hemorrhage started. Tetracycline is the drug most often effective and the therapeutic response is dramatic and rapid. Following infection, immunity can be lifelong.

Ehrlichia

The same brown dog tick that carries and transmits Rocky Mountain Spotted fever is also responsible for the organism Ehrlichia canis, the cause of a deadly blood infection in dogs. Although this organism affects dogs throughout the country, it is primarily found in the warmer southern states. Ticks carry it after feeding on an infected dog. Mild signs show up in the newly infected dog between 8-20 days after exposure.

The first signs of infection can include a loss of appetite, mild fever, swollen lymph glands, discharge from the nose or eyes, lethargy, stiffness and edema of the legs, reluctance to walk and difficulty in breathing. This is the acute stage and clinical signs can improve within 24-48 hours if the dog responds well to tetracycline or doxycycline. Death is rare in this acute stage, but the dog may remain asymptomatic, showing no sign of the disease, or the chronic disease may ensure.

If a dog develops severe chronic Ehrlichiosis, supportive therapy may be necessary for 3-6 months with death being inevitable despite treatment. Clinical findings in the chronic stage include widespread hemorrhages under skin and mucous membranes, pneumonia, kidney failure, continued weight loss with depression and weakness. The organism lives and reproduces inside white blood cells, causing permanent and lethal changes in the bone marrow and varying grades of anemia. Dogs with only mild chronic stages will have less damage to the bone marrow and may be able to have the symptoms reversed with treatment and time, and survive.

The disease can only be detected and diagnosed by blood tests done by your veterinarian, or by a combination of clinical signs and response to treatment. Any dog that tests positive for the disease must remain in isolation until cleared, and all dogs exposed to a recurring problem of ticks should be put on a daily regime of tetracycline to prevent any further spread of the disease by the ticks.

Lyme Disease

Lyme disease is a tick-borne, immune mediated inflammatory disease of dogs, horse, wild animals, and humans. The disease is carried by the spirochete, Borrelia burgdorferi, and transmitted by ticks carried by raccoons, opossums, mice and white-tailed deer. Lameness and fever are the first clinical signs of the disease, progressing to loss of appetite, fatigue and arthritis involving one or several joints.

The arthritis may become chronic, especially with the joints of the forelegs becoming painful, swollen, and hot to the touch. Additional signs may be nervous system, cardiac, and kidney problems. Treatment with tetracycline, erythromycin, or penicillin antibiotics has been effective if diagnosis is correctly made through blood testing.

Since the tick does not transmit the spirochete immediately on attachment to the dog, frequent examination and removal of any tick immediately is the best prevention of Lyme disease.

Ingle & Mead created 9/13/97, updated 03/05/2002