TroCCAP Tropical Council for Companion Animal Parasites on LinkedIn: Leishmania infantum, transmitted by phlebotomine sand flies, causes a… (2024)

TroCCAP Workshop in Santa Cruz, Bolivia 🇧🇴 Sharing information on the diagnosis, treatment and prevention of canine and feline parasites in the tropics, with over 100 vets and vet students from different regions of Bolivia.#troccap #parasitology #parasites #dogs #cats #veterinarymedicine #clínicaveterinária #médicinaveterinária #bolivia #leishmaniose

21

1 Comment

Between 4 and 7 March 2024, the city of Lisbon in Portugal welcomed many prominent Parasitologists from around the world for the Vetoquinol 3rd Scientific Roundtable in Parasitology, focused on feline parasitology. Among them, five of our TroCCAP members! Discussion revolved around the latest research and data in this fascinating and increasingly important field.

27

Cat Tapeworm (Taenia taeniaeformis)Taenia taeniaeformis is a common tapeworm of cats. It is zoonotic, but of minor significance. The infections in cats are very rarely of clinical significance with only a few reports of intestinal obstruction due to extremely heavy infections. Cats get infected by ingestion of rodent intermediate hosts.Taenia taeniaeformis infections in cats can be confirmed by the presence of distinctive whitish proglottids (segments) in the faeces bearing a single lateral genital pore. Proglottids, as opposed to eggs, are shed in faeces, so the absence of eggs on standard faecal flotation does not rule out infection. Eggs are typical Taeniid eggs, spherical, 31-36 μm in diameter with a hexacanth embryophore.The control of T. taeniaeformis can be achieved by treating cats against tapeworms every 2- 3 months, by preventing cats from hunting and eating rodents, and by controlling rodent populations.Adults of T. taeniaeformis have been recovered from the intestines of human patients and in a single case a strobilocercus (larval stage) was found in a serous cyst present in the liver of a human patient, who died from unrelated causes. Nevertheless, this parasite is considered of minor zoonotic significance. For more info: www.troccap.comPhoto credits: Andrei-Daniel Mihalca (1) and Rebecca J. Traub (2).

73

1 Comment

Echinococcus granulosus The parasite is of no clinical significance in dogs, but eggs passed by dogs infect humans and livestock to produce hydatid cysts in visceral organs resulting in significant public health and economic impacts. Echinococcus granulosus is distributed globally, but appears to be highly endemic in cooler regions of the tropics and sub-tropics (e.g. northern India, East Africa, Southern Brazil), especially in rural areas where offal is readily accessible to farm and community dogs.Diagnosis in dogs is essential to prevent environmental contamination and human infection and should be based also on the animal’s history i.e. access to raw offal. Detection of eggs and proglottids on standard faecal flotation is unreliable as eggs are rarely shed in faeces. When present, eggs are morphologically indistinguishable from eggs of Taenia spp. Anthelmintic purgation and examination of adult worms is not recommended due to the zoonotic risk associated with accidental ingestion of E. granulosus eggs. Adult worms are minute, measuring 3-9 mm, with a maximum of 3 segments.Praziquantel given orally at 5 mg/kg is the drug of choice. Humans acquire infection by ingesting eggs through direct contact with the dog (eggs stick to dogs’ coat and are infective immediately upon defaecation) or via ingesting eggs in contaminated food or water. In humans, infection may be asymptomatic or may reflect impairment of organ function (e.g. liver, lung, spleen, brain, heart, etc.) as a result of hydatid cysts putting pressure on adjacent organs. Typically, hydatid disease in humans has a prolonged incubation period of years (cysts take time to grow). Rupture or leakage of a cyst can lead to fatal anaphylactic shock. Treatment is complicated and usually requires a combination of surgical and chemotherapeutic intervention. Credits: Dr. Alicia RojasFor more info: www.troccap.com

42

Dipylidium caninum is a common tapeworm of dogs and cats. It is transmitted when a dog ingests infected fleas or chewing lice. Although zoonotic, its occurrence in humans is limited.Dipylidium caninum infections in pets are usually asymptomatic. However, the passage of gravid segments through the rectum will cause irritation and the dogs will usually ‘scoot’ and rub their perineum along the ground. In rare cases, dogs with heavy infections may develop enteritis and/or intestinal obstruction.Diagnosis can be made through history (i.e. lack of flea control, lack of deworming with praziquantel) and by detecting proglottids in the faeces, coat, and bedding or around the anus. The proglottids of D. caninum can be differentiated from those of Taenia spp. by shape and presence of two bilateral genital pores located in the middle of the segment. Squashing a gravid proglottid will reveal the typical egg packets. Occasionally, egg packets are detected by faecal flotation methods but with low sensitivity.Treatment of D. caninum infection is by praziquantel at 5 mg/kg every 2 weeks, combined with flea or lice control.D. caninum infection, usually of children, occasionally occurs via ingestion of infected adult fleas. Children may be asymptomatic or show perianal irritation and/or light intestinal disturbances. Proglottids may be observed in the faeces or around the perianal area of the child.For more info: www.troccap.comPhoto credit: Dr. Alicia Rojas

63

2 Comments

Angiostrongylus vasorum is a strongylid nematode parasitizing the pulmonary arteries of dogs and wild canids, responsible for often severe respiratory disorders but also other associated clinical signs. Infection of dogs is via ingestion of intermediate (gastropods) or paratenic (microvertebrates) hosts. Angiostrongylus vasorum is distributed in Europe, North America and South America (Brazil, Argentina, Bolivia, and Colombia). Although some cases are asymptomatic, symptomatic cases can be severe. Common clinical signs include respiratory disorders (cough, dyspnoea), lethargy, coagulopathy, neurological signs. Chronic cases present also anaemia, weight loss, fever, and weakening. Various approaches are available for diagnosis. Detection of L1 in faeces (Baermann method) is possible during the patent phase of the infection. Differential diagnosis with other larval stages (i.e., Crenosoma, Filaroides) should be made. Various serologic methods are also available, including a rapid in-clinic test for the detection of circulating antigens. Macrocyclic lactones are effectively used for the treatment of canine angiostrongylosis. Moxidectin (2.5 mg/kg, spot on), repeated after 4 weeks or milbemycin oxime (0.5 mg/kg PO), weekly for 4 weeks. Another option is fenbendazole (25-50 mg/kg PO), daily for 3 weeks. To avoid thrombotic complications, supportive therapy is needed. Photo credit: Andrei-Daniel MihalcaFor more info: www.troccap.com

3

Hepatozoonosis is a tick-borne disease caused by apicomplexans of genus Hepatozoon, distributed mainly throughout the tropics and subtropics. Mild to severe disease may manifest in dogs.Hepatozoon canis in found in Europe, Africa, Asia, Latin America and parts of the USA, whereas H. americanum is restricted to North America.Hepatozoon canis infects the haemolymphatic tissues and causes anaemia and lethargy. The infection varies from subclinical in apparently healthy dogs to severe cases with lethargy, fever, cachexia and pale mucous membranes due to anaemia.The Hepatozoon canis infection is frequently diagnosed by microscopic detection of intracellular gamonts in neutrophils and monocytes in stained blood smears. A higher sensitivity can be achieved if buffy coat smears are performed. The degree of parasitaemia is proportional to the severity of clinical signs. PCR of whole blood for H. canis detection is sensitive and specific.Hepatozoon canis infection is treated with imidocarb dipropionate at 5-6 mg/kg IM or SC every 14 days until gamonts are no longer present in blood smears. The decrease of parasitemia is slow and usually requires several repeated imidocarb treatments. Image credit: Dr. K. KamyingkerdFor more info: www.troccap.com

131

Lice are small, wingless, dorsoventrally flattened insects that live in close contact with the skin and hair of their hosts. They may cause direct injury to the skin and act also as vectors or intermediate hosts of pathogens such as Trichodectes canis for Dipylidium caninum, and Heterodoxus spiniger for Acanthocheilonema reconditum. According to their feeding habits they are classified as sucking lice or chewing lice. The species found on companion animals include Linognathus setosus (sucking lice), and T. canis and H. spiniger (both chewing lice). Cats have only chewing lice (Felicola subrostratus). Heavy infestations are usually seen in young animals.Usually, the owners do not notice lice infestations on their pets and they are found only at a more thorough examination of the fur. Usually, lice produce an asymptomatic infestation. Pruritus is the main clinical sign. A rough, dry, matted coat can be observed as well as erythema, scaling, crusting, and hair loss (specifically around ears, neck, shoulders, groin, and rectal regions). Restless behaviour is sometimes noticed by the owner. Anaemia is possible, especially in young or immune-suppressed animals, caused by blood loss due to heavy L. setosus infestations, and less frequently T. canis or H. spiniger infestations.Image credit: University of Melbourne parasitology image library)More information: www.troccap.com

61

1 Comment

Sarcoptic mange or scabies is a highly contagious and the most pruritic cutaneous disease of dogs.Sarcoptes scabiei causes sarcoptic mange or scabies of humans, dogs, foxes, horses, cattle, and other mammals. Sarcoptes scabiei infests a wide range of hosts, but a significant degree of host specificity is known in this parasite, so when interspecific transmission does occur, the resulting dermatitis tends to be atypical and transient.In dogs, the lateral part of the elbow and the pinna of the ear are favourite starting places. The lesions consist of follicular papules, erythema, crusts of blood and dry serum, and excoriations caused by intense scratching.Dogs with chronic disease, and generalized lesions show seborrhoea, severe skin thickening, fold formation, crusting, peripheral lymphadenopathy, and emaciation, leading even to death if not treated. Asymptomatic carriers may exist. Although S. scabiei is not commonly reported from cats, symptoms such as extensive hair loss over the ears, head, neck, abdomen, and tail, and thickened, scaly, and wrinkled skin on the abdominal region have been reported in kittens.Photo credit: Andrei-Daniel MihalcaMore information: www.troccap.com

1