What are the diseases transmitted by ticks?

The different ticks

Two species of ticks frequently attack the dog in European countries. These are Dermacentor reticulatus, which is found throughout France, mainly in spring and autumn, and Rhipicephalus sanguineus, which is especially active in spring in the south and in Mediterranean regions. These two ticks are never observed in humans. A third tick, Ixodes Ricinus, common to man and dog, can be found mainly in woods and forests rich in deer.

The ticks attach themselves to the dog’s skin with their rostrum, which acts like a harpoon. Then, they secrete saliva that will “digest” the cells and small blood capillaries to form a blood slurry that it sucks up to feed itself. Fixation sites are not chosen at random: ticks prefer thin-skinned areas such as the perineum, the perimeter of the anus, the inner thighs, the base of the legs or the ears.

By attaching themselves to the dog, ticks therefore cause a small wound on the skin. This small wound can become infected or itch a little. Afterwards, if the tick is abruptly torn off, part of the rostrum may remain in the skin, sometimes resulting in a small, firm, painless and benign nodule. In addition, some sensitive dogs may develop an allergic reaction to contact with the tick’s saliva.

In addition to these small annoyances, ticks can transmit more serious, potentially fatal diseases.

Diseases transmitted by ticks

1) Babesiosis (or piroplasmosis)

Babesiosis, also called piroplasmosis, is due to the multiplication in the red blood cells of the parasites Babesia canis and, to a lesser extent, Babesia vogeli. This parasite is inoculated by the ticks R. sanguineus and D. reticulatus during their blood meal. Babesiosis is therefore not contagious from one dog to another. Young dogs are the most sensitive.

This disease is mostly found in the southwest, most often in spring and fall, which are the main periods of tick activity.

By multiplying inside the red blood cells, the babesias make them burst. In dogs, this manifests itself as anemia (pale mucous membranes) or jaundice (yellow mucous membranes). Liver and/or kidney failure may also occur. These symptoms appear after about one week of incubation and are of varying severity. During an acute episode of babesiosis dogs may be very depressed with a high fever and dark, brownish urine. There are also chronic forms in which relapses and improvements follow one another.

While spontaneous recovery is possible, the prognosis is much better with early treatment. This involves the use of molecules that act specifically on babesias, as well as symptomatic treatment if the veterinarian considers it necessary (infusion, transfusion). The improvement must be significant and rapid.

For prevention, there is a vaccine that confers partial protection. It reduces the severity of symptoms in case of infection. This vaccine is not routinely used. Its interest depends on your dog, his level of exposure to ticks, and should be discussed with your veterinarian.

2) Ehrlichiosis (or Rickettsiosis)

Ehrlichiosis is another parasitic disease, transmitted by R.sanguineus. In France, it is mainly present in the Mediterranean region. The cause is a parasite called Ehrlichia canis, which develops in blood cells. Here again, the disease can occur in an acute or chronic form.

After an incubation period of about ten days, the acute phase is characterized by very general signs such as fever and severe depression. If the disease is chronic, signs related to blood changes such as anemia or nosebleeds are observed. If left untreated, the signs may disappear spontaneously, but the dog remains a carrier of the parasite and recurrences are frequent. The disease is fatal in one out of three cases.

3) Borreliosis (or Lyme disease)

Borreliosis, better known as “Lyme disease”, affects dogs as well as humans. It is caused by Borrelia Burgdorferi, a bacterium transmitted by the tick Ixodes Ricinus. Most often the infected dog does not show any symptoms. When the disease expresses itself, arthritis is observed as in humans: the dog limps intermittently. The incubation phase is long, the signs only appear 2 to 5 months after the tick bite. The pain can be severe, possibly accompanied by fever or serious cardiac or renal complications, or even neurological disorders. Treatment is based on the administration of antibiotics. It is long and difficult, and it seems that complete eradication of the parasite is almost impossible.

As with babesiosis, a vaccine is available. It is mainly aimed at highly exposed dogs such as hunting dogs for example, from the age of 3 months. For others its interest is questionable, given that this disease remains quite rare. Protection is never total and the vaccine does not exempt from applying preventive measures against ticks.

4) Hepatozoonosis

Unlike the previous ones, this disease is transmitted by ingestion of contaminated ticks, for example if the dog is bothered by the tick and the bite. The parasite, Hepatozoon canis develops in the white blood cells, mainly in summer, in dogs that spend a lot of time outdoors. The seriousness of Hepatozoonosis lies in the fact that it induces an immunodepression, and thus promotes the appearance of other diseases. In many cases no symptoms are observed. If the disease is present, the dog will show fever, weakness and diffuse pain, which results in difficulty in moving and lameness.

The prognosis is bleak, as at present there is no really effective treatment available.

The fight against ticks

Even if for certain diseases treatments or even vaccines are available, the fight against ticks themselves must remain the first measure of protection for your dog.

Immediately after each walk, and especially during the periods of greatest risk, carefully inspect your dog, paying particular attention to areas where the skin is thin (earlobes, inner thighs). If you observe a tick, remove it quickly, before your dog has time to pull it out himself. The use of tweezers should be avoided because there is a high risk of leaving a piece of the rostrum in the dog’s skin. Once widely used to “numb” ticks before removing them, ether is no longer available over the counter in French pharmacies because of its significant toxicity. Ideally, you should buy “tick remover” hooks, which you can easily find in any pharmacy. Inexpensive and reusable, they are often sold in pairs, of different sizes depending on the size of the tick to be removed. You just have to grasp the tick delicately with the hook, and make a quarter turn to remove it without any difficulty.

Because prevention is always better than cure, it is better to treat your dog preventively with antiparasitic drugs. Ask your veterinarian for advice. They are available in different forms (pipettes, spray, collars, etc.), which provide varying periods of protection. Be careful, we often forget that not all antiparasitic collars are water resistant…