Parasitology

• Babesia • Theileria

• Mature tick feeds and becomes infected • Babesia sexually multiplies in the tick’s intestines • Asexual multiplication also occurs in multiples tissues • Vernicules formed (which also divide) Either • In tick salivary glands or • In tick ovary and eggs • Tick feeds on the cow and transmits infection • Asexual multiplication in Bovine RBCs

Infected RBCs rupture leaving free antigen in the blood which then sticks to the surface of other RBCs missdirecting the host immune response while babesia parasites enter other RBCs

Sudden Onset: - Fever - Anaemia - Haemoglobinuria - Continous diarrhoea - May result in death (if survie may become a carrier)

Mostly in defined endemic areas, sporadic, spring and autumn time affecting hill grazing, over 2 year old, often newly purchased or stressed animals

• Vector (species, population etc) • Host susceptibility (multi factorial)

• Age: calves under 9 months are refactory, infected but not sick or Adults are susceptible until infected • Immunity develops rapidly but may ane • Carrier state • Stress

Enzootic stability = Continual re-infection resulting in consistent high level of herd immunity and less disease Enzootic instability = Infrequent re-infection resulting in some animals with low immunity and more disease

• Susceptible animals moving to an infected area • Infected ticks moving to a clean area • Infected cattles added to area with clean ticks • Reduction in tick numbers • Stress

Intra-cellular, protozoan parasites of macrophages causing disease in humans, dogs and wild animals in S. Europe, Africa, Aia and S. america

• Sandfly ingests leishmania • Intermediate host of sandfly • Transforms and multiplies in the fly gut and migrates to proboscis • Dog infected when sandfly bites; leishamnia transforms in the macrophage

• Promastigote • Amastigote

• Infection of the vertebrate host = foci of proliferating organisms in skin (cutaneous leishmaniosis) and internal organs (visceral leishmaniosis) • Very long incubation period (months to years) • Many dogs that are infected are asymptomatic • Infection does not equal disease

Cutaneous: Shallow skin ulcers e.g. lip, eyelid, ear pinna Visceral: - More common - Chronic wasting condition - Generalised eczema, hair loss around the yes - Intermittent fever - Generalised lymphadenopathy

• Disease dependent on sandfly distibution • Reservoirs of infection e.g. wild animals such as rats • Mechanism of transmisson is sandlfy bites or direct contact

• Demonstrate leishmania organisms in skin smears/scrapings, lymph node/ bone marrow biopsies • Serology • PCR

• Chemotherapy: prolonged, expensive, suppresses infection • Prevent sandfly bites: colalrs/sprays • Vaccination e.g. CaniLeish or Letifend

• Cause of canine heartworm disease • Is a dilarial nematode • Serious cause of canine morbidity and mortality • Cats and ferrets are also susceptible

Usually: - Exercise intolerance - Chronic heart failure Sometimes: - Acute collapse

• No eggs, microfilariae (300 micrometers long) • Found in 60% of infected dogs • Microfilariae ingested by mosquito • Develop into L1-L3 in 10-14 days under optimal conditions (14 centigrade) • L3 transmitted by feeding mosquito • L3 progresses to L4 and L5 • L5 migrates to the heart

Prophylaxis is the basis of control: All year round in the tropics and one month before mosquito season and two months after in temperate zones

• Blood: microscopy for microfilaria, serology • Ultrasonography for adult worms

Doxycycline Macrocyclic lactone

• Man can be host to an aberrant infection • No parasite development • No microfilaria • Larvae die in the pulmonary artery