Doença de Carrapato/Tick-Borne Fever in the Baixada Cuiabana. Anaplasmosis/Ehrichiosis/Babesiosis

This article is for purposes of clarification of a veterinary issue in Cuiabá, that of tick-borne fever, which is rife in dogs here. Written for final-years and new grads in veterinary medicine.

I love identifying the sciences involved in veterinary medicine.  Today's text envelopes the sciences of parasitology, haematology, cycnology and posology.  Paratology because Ehrichia spp, Babesia spp. and Anaplasma spp are all blood cellular parasites. Haematology because, this is the science that studies the blood, and, as mentioned above, these are blood parasites. Cynology because cases that I looked at this week involved dogs, and the study of dogs is called cynology.

The correct treatment of a disease depends upon its diagnosis.

Canine Anaplasmosis.

A word on epidemiology.  Tick-borne disease here in the Cuiabá Basin is caused by the bacterium Anaplasma platys, a gram-negative, obligate intracellular bacterium.

It causes thrombocytopaenia,which is a drop in the blood stream's red blood cells.

Dogs become infected when bitten by an infected tick.

Symptoms are characterised  by sudden onset, a reluctance to move due to painful limbs and high fever. This in cases uncomplicated by secondary infection.

Treatment is with doxycicline, 10mg/kg for 28 days.
Again, this is in uncomplicated cases.


Reference:

http://www.capcvet.org/capc-recommendations/ehrlichia-spp-and-anaplasma-spp1/. Accessed 8th April 2016.

Canine Babesiosis

Ticks 

Ticks such as Rhipicephalus sanguineus are extremely common in the Cuiabá Basin, the Baixada Cuiabana of Mato Grosso, Central Western Brazil.  Owners of houses where ticks have been seen should begin a spraying regime, spraying the whole property with amitraz.

The bacteria of the genus Babesia readily infect dogs when these are bitten by an infected host, the ticks Rhipicephaphis sanguineus, Dermacentor spp, and Haemaphysalis spp.  Three species of large Babesia (Scoeman, 2009) infect dogs worldlwide,  In the Cuiabá Basin the least pathogenic one is found, Babesia vogeli.  There is also the possibility of Babesia gibsoni.

Diagnosis of Babesia spp.

Improved PCR techniques have allowed better diagnosis.

Control.

Both trans-stadial and transovarial transmission in the tick can occur. Trans-stadial means that the bacterium can remain in the body of the host tick as the latter grows, from nymph to larva to adult. Babesoa spp can also be trasnmitted by blood transfusion.

Risk Factors

Babesiosis mostly occurs in young dogs, but those of all ages can be affected.

Incubation period.

This varies from 10 to 28 days depending upon the species of Babesia.

Pathogenesis and Clinical Signs

Severeity of Babesios depends upon

• the species of Babesia sp.,
• the presence of seconadary infections
• age of the pet
• immune status of the pet

The disease can be peracute or chronic or even subclinical. When severe there is hamolytic anaemia, acid-base alterations, there can be multiple organ failure and acute renal failure, hepatopathy, icterus, hypoglycaemia, respiratory distress,  neuropthaies and there can pancreatitis in the presence of other complications.

Treatment of Babesiosis.

Eliminate thee parasite and reverse the anaemia with fluid therapy.  I spray my peoperty with 20ml/20litres of Ivermectin, every two or three weeks.

Prognosis of Babesiosis.

This is usually good.

Babesiosis as a Zoonosis.

Whilst Babesios can affect human, it is not passed from the pet but is contracted in the same way, that is, by the victim being bitten by an infected tick.

Reference.

Schoeman, J.P. Canine Babesiosis. Ondestepoort Journal of Veterinary Research, 76: 59-66. (2009).

Incidentally, the only place I have come across with a worse tick problem than Cuiabá is Aride Island, in the Seychelles.  The Sooty Terns there used to suffer terribly with infestations of ticks.

This is a bottle of Amitraz.  That is the commercial name.  The active ingredient is ivermectin.  Ivermectin acts on the central nervous system of the tick.  

I dissolve 20ml of Ivermectin in 20litres of water and use this spray gun to spray my whole property every three weeks to control ticks.