Ticks are annoying little pests that feed on the blood of their host animals. They belong to the genus of mites and are found almost everywhere on earth. Many types of ticks are carriers of numerous diseases, as they introduce tiny pathogens into the host’s organism during the sucking process, where they then spread through the blood and can lead to sometimes life-threatening diseases. One such tick-borne disease is canine anaplasmosis. You can find out everything you need to know about anaplasmosis in dogs in this article.
What is anaplasmosis in dogs?
Canine granulocytic anaplasmosis is a bacterial infection with the pathogen Anaplasma phagocytophilum, which belongs to the Rickettsia order and is primarily transmitted by ticks such as the wood tick. In fact, around 1/3 of all dogs in Germany have antibodies against this pathogen, which means that they have been infected with it before. In some regions where ticks have a particularly high rate of anaplasma infection, up to 50% of all dogs are infected. However, only very few dogs actually show symptoms of the disease, and in most of them the infection goes completely undetected.
Why some dogs get sick while others don’t, even though they carry the same pathogen, has not yet been clarified. Presumably, different genetic variants of the bacteria determine their actual level of danger. It seems clear, however, that a dog once infected carries the pathogen for life, even if it is not visibly ill.
What is anaplasmosis in dogs?
It is a bacterial infection transmitted by ticks.
Anaplasmosis in dogs – how it develops
Ticks – practically every dog gets to know these blood-sucking parasites several times in its life, especially if the four-legged friend frolics a lot in fields, forests, and meadows. There the tick sits on blades of grass or in the bushes and just waits for a suitable host animal to come by – it then holds on to the dog’s fur, looks for a suitable place and pierces the skin with its mouthparts. She then starts her blood meal with her proboscis and at the same time releases saliva into the wound to prevent blood clotting. Otherwise the tiny skin wound would close again very quickly.
About 24-48 hours after the bite, the anaplasma collect in the saliva of the tick and then enter the blood of its definitive host unhindered. Here they colonize the white blood cells, especially the so-called neutrophilic granulocytes, where they multiply. Bacteremia occurs within a few days, i.e. the bacteria spread through the blood and thus throughout the body. Finally, different organs such as the kidneys, liver, lungs, gastrointestinal tract and also the central nervous system are infected. The dog’s immune system works actively against the pathogens and produces antibodies that prevent an outbreak of anaplasmosis with recognizable symptoms in most dogs.
An infection from dog to dog or even to humans is not yet known. However, a certain risk of infection through contact with blood when handling infected animals cannot be completely ruled out.
Can a dog die from anaplasmosis?
Anaplasmosis is only dangerous for dogs with a weak immune system or serious previous illnesses.
Symptoms of anaplasmosis in dogs
If the dog’s immune system cannot prevent the outbreak of the disease, the first very acute symptoms usually appear about one to three weeks after the tick bite. At first, the disease appears rather unspecific, the dog shows a severely disturbed general condition, is listless and has no appetite. In the blood, anaplasmosis leads to a significant reduction in the number of blood platelets (=thrombocytopenia), which are responsible for blood clotting, among other things. This can lead to bleeding into the skin or organs. The possible symptoms of anaplasmosis are:
- Fever (body temperature over 39°)
- exhaustion, tiredness
- loss of appetite, weight loss
- vomiting, diarrhea
- Bleeding, for example in spots in the mucous membrane of the mouth
- nosebleeds
- pale mucous membranes from anemia
- Lameness from polyarthritis
- Seizures and other neurological problems
- Cough
If the disease is not treated in the acute stage, it turns into a chronic form after about two to three weeks. Flares with fever occur again and again between symptom-free phases. Such chronic diseases can lead to consequential damage to the affected organ systems.
Is anaplasmosis contagious in dogs?
The causative agents of anaplasmosis are transmitted by ticks, direct infection through infected dogs has not been described.
Diagnosis of anaplasmosis
Since the clinical symptoms of acute anaplasmosis are quite non-specific and could also indicate other diseases, it is essential to identify the pathogen to confirm the diagnosis. For this purpose, a blood sample is taken from the dog by the veterinarian after a detailed questioning of the dog owner about the observed signs of illness and a first general examination. In the acute phase, the DNA of Anaplasma phagocytophilum can then be clearly detected in the laboratory using a PCR (= polymerase chain reaction) test.
Antibodies against the pathogen can be reliably detected no earlier than 30 days after the first infection. However, since an acute illness would have already broken out at this point in time, the detection of antibodies is more of an indication that the dog has come into contact with anaplasma at some point and that the infection is not clinically manifest.
But since, as mentioned, about 1/3 of all dogs in Germany carry antibodies against anaplasma without developing symptoms, there is still a residual risk, even with a positive PCR test, that the dog carries anaplasma, but the symptoms of the disease have another cause. Therefore, in addition to the examination findings, PCR or antibody test, thrombocytopenia must also be verified via a blood count. If there is a rapid increase in the number of platelets in the blood count during the initiated treatment against anaplasma, the diagnosis is only confirmed.
What to do with anaplasmosis?
Once the veterinarian has clearly diagnosed the disease, antibiotic therapy is initiated.
Treatment options and therapy of the infectious disease
If anaplasmosis in dogs is detected in good time and the diagnosis is confirmed by means of a PCR test and blood test, antibiotic therapy can be initiated. Blood tests within the first few days of treatment show whether the therapy is working.
In most cases, a significant improvement in the dog’s general condition is quickly achieved, and after the end of the antibiotic therapy (usually after about three weeks) the four-legged friend is healthy again. Since the pathogens can probably not be eliminated completely, but remain in the body, there is also the possibility of a chronic course of the disease with flare-ups of fever in some dogs, especially those with an immune deficiency. In an otherwise healthy dog, infection with Anaplasma phagocytophilum does not affect life expectancy, whether the disease develops or is asymptomatic.
Anaplasmosis in dogs – prevention and prophylaxis
The best way to prevent anaplasmosis is to protect your dog from ticks. On the one hand, a dog should be checked for ticks after every walk in nature. Especially in the warmer season from spring to autumn, ticks can be found almost everywhere on meadows, fields and in the forest. Since the transmission of most pathogens by the tick takes place with a time delay several hours after the tick has attached itself, an infection can be prevented by removing the tick promptly.
Applying medicated tick and other parasite repellents via sprays, spot-ons, or pills will also help protect your dog from ticks. Even if a tick bites, the active ingredient causes it to die off quickly, even before pathogens are transmitted. There is no vaccination against anaplasmosis.
