Written by: Dr. Marlene Zähner

A few weeks ago, I was informed by Gracien and Christian that Lily was not eating and seemed to be uncharacteristically lethargic.  Because the handlers actually spend more time with the bloodhounds than with their own children, they’re acutely aware of any changes in their health. I suggested they get in touch with Dr. Eddy of MGVP, since he was close by in Bukima. He gave Lily a check up that afternoon and made the decision to put her on tetracycline, an antibiotic. I advised Christian to also add Rimadyl to the treatment regimen to knock down any inflammation.  Later that evening, neither Dr. Eddy nor I were satisfied with Lily’s progress, so we decided to confer with a specialist in Nairobi. LuAnne sent pictures along with our preliminary veterinary work-up and he strongly suspected that Lily had been infected with T. evansi, a protozoan that causes trypanosomiasis or sleeping sickness. The vector of transmission in Africa is often tsetse flies, which exist in abundance in Lulimbi — where the dogs just completed their last deployment. Tsetse flies carry the T. evansi protozoan in their saliva and transmit it to mammals through their bite. T.evansi is by no means endemic only to Africa. The protozoan is also found across Asia and Latin America.

Tsetse fly biting a human (sourced online)

Transient edema in Lily's leg caused by trypanosomes

Transient edema below Lily's collar

Trypanosomiasis can be quickly and effectively treated with Triquin, which is what we immediately gave Lily.  By morning, her symptoms began to disappear, and a day later, she was virtually asymptomatic.  We also closely examined the other bloodhounds and found that Stella was exhibiting mild symptoms, so we put her on a course of Triquin as well. I’m happy to report that all dogs are now trypanosome-free and back to being their their energetic selves.

Lily parasite-free and happy!

More on trypanosomaisis from the 2010 OIE Terrestrial Manual:

Definition of the disease: Trypanosoma evansi causes a trypanosomosis known as ‘surra’. It
affects a large number of wild and domesticated animal species in Africa, Asia, and Central and
South America. The principal host species varies geographically, but camels, horses, buffalos and
cattle are particularly affected, although other animals, including wildlife, are also susceptible. It is
an arthropod-borne disease; several species of haematophagous flies, including Tabanids and
Stomoxes, are implicated in transferring infection from host to host, acting as mechanical vectors. In
Brazil, vampire bats are also implicated in a unique type of biological transmission.

Description of the disease: The general clinical signs of T. evansi infections: pyrexia directly
associated with parasitaemia together with a progressive anaemia, loss of condition and lassitude
are not sufficiently pathognomonic for diagnosis. Recurrent episodes of fever and parasitaemia
occur during the course of the disease. Oedema, particularly of the lower parts of the body,
urticarial plaques and petechial haemorrhages of the serous membranes are sometimes observed
in horses. Abortions have been reported in buffalos and camels. Nervous signs are common in
horses. The disease causes immunodeficiencies that may be of high impact when interfering with
other diseases or vaccination campaigns (foot and mouth disease and haemorrhagic septicaemia
for example).
Identification of the agent: The general clinical signs of T. evansi infection are not sufficiently
pathognomonic for diagnosis. Laboratory methods for detecting the parasite are required. In early
infection or acute cases, when the parasitaemia is high, examination of wet blood films, stained
blood smears or lymph node materials might reveal the trypanosomes. In more chronic cases, or
more generally when the parasitaemia is low, the examination of thick blood smears, as well as
methods of parasite concentration and the inoculation of laboratory rodents are required. In
apparently healthy carriers (animals without clinical signs), parasites are rarely observed and
mouse inoculation gives the best results. Several primer pairs targeting the subgenus
(Trypanozoon) or the species-specific (T. evansi) parasitic DNA sequences are available for
diagnosis by polymerase chain reaction (PCR). PCR is more sensitive than parasitological
examination, but it may give false-negative results when the parasitaemia is very low; in these
cases, suspicion of potential carriers can only be confirmed by serological examination.

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