1. Toxoplasmosis A diagnosis of exclusion

2. Kenzie McLaren One-year-old castrated male British Shorthair One-day history of hindlimb ataxia and paresis 20% weightloss in 11 weeks Initial PE: unremarkable PCV low: 22% [29-45%] Pelvic radiography unremarkable Referred to neurology service 3. Initial Presentation 4. Summary of Findings Pyrexia (39.3 to 40.3C) Initial stiff hindlimb gait Reduced exercise tolerance: forelimbs became stiff to the point of collapse Normal spinal reflexes, but some myoclonus No proprioceptive deficits Suggestive of a neuromuscular disorder DDx: neuropathy, myopathy or junctionopathy 5. Summary of Findings Pyrexia (39.3 to 40.3C) Initial stiff hindlimb gait Reduced exercise tolerance: forelimbs became stiff to the point of collapse Normal spinal reflexes, but some myoclonus No proprioceptive deficits DDx: neuropathy, myopathy or junctionopathy 6. Summary of Findings Pyrexia (39.3 to 40.3C) Initial stiff hindlimb gait Reduced exercise tolerance: forelimbs became stiff to the point of collapse Normal spinal reflexes, but some myoclonus No proprioceptive deficits Initial CK and ACh-R antibody (pending) tests DDx: neuropathy, myopathy or junctionopathy 7. Electromyography (EMG) Abnormal spontaneous muscle activity Normal nerve conduction velocities Normal repetitive nerve stimulation DDx: myopathy or junctionopathy 8. Problem List Neurological Ataxia Stiff gate Reduced exercise tolerance Myoclonus (EMG confirmed) Dx: Myopathy (idiopathic or secondary) DDx: Infectious, Autoimmune, Neoplastic Other Weightloss (too acute) Pyrexia Anaemia (rarely) CK elevated (84X upper ref.) 9. Haematology Erythrocytes Low haematocritt Polycythaemia Haemaglobinaemia Leukocytes Leukopaenia Neutropaenia Lymphopaenia 10. Blood Smear Anaemia poorly regenerative Howell-Jolly bodies in RBCs Occasional poikilocytes Mild toxic left shift Pro-eosinophils containing basophilic granules Occasional hyperchromatic lymphoid cells Direct Coombs Test Negative DDx: chronic infectious, autoimmune, neoplastic 11. Biochemistry Hypoproteinaemia Low globulin levels High AST (2X upper ref.) High ALT (3X upper ref.) High CK (now 180X upper ref.) High fasting bile acids (2X upper ref.) Need bile acid stimulation test DDx: myopathy, mild cholangiohepatitis 12. Biochemistry Hypoproteinaemia Low globulin levels High AST (2X upper ref.) High ALT (3X upper ref.) High CK (now 180X upper ref.) High fasting bile acids (2X upper ref.) Need bile acid stimulation test DDx: myopathy, mild cholangiohepatitis 13. Thoracic Radiography Excessive mild bronchial pattern and cardiomegaly L R DDx: chronic bronchitis, early onset asthma DDx: myocarditis, HCM 14. Microbiology Report Mucal swab taken from endotracheal tube due to respiratory noise during anaesthesia Culture: Gram negative cocci & large rods Sensitive to Clavunated amoxicillins Azithromycin Doxycycline Marbofloxacin 15. Problem List Neurological Ataxia Stiff gate Reduced exercise tolerance Myoclonus (EMG confirmed) Dx: Myopathy (idiopathic or secondary) Dx: Mild cholangiohepatitis (potentially) Dx: Chronic bacterial bronchitis DDx: Infectious, Autoimmune, Neoplastic Other Weightloss Pyrexia Poorly regenerative anaemia CK elevated (180X upper ref.) Elevated liver enzymes Cardiomegaly (DDx: myocarditis) 16. Feline Infectious Disease Panel NEGATIVE: Feline Leukaemia Virus (FeLV) Antigen NEGATIVE: Feline Immunodeficiency Virus (FIV) Immunofluorescent Assay NEGATIVE: Feline Corona Virus (FCoV) Antibody Titre POSITIVE: Toxoplasma Antibody Titre IgG Seropositive (4X upper ref.) 17. Problem List Neurological Ataxia Stiff gate Reduced exercise tolerance Myoclonus (EMG confirmed) Dx: Myopathy Dx: Mild cholangiohepatitis (potentially) Dx: Chronic bacterial bronchitis Dx: Myocarditis (potentially) Dx: Chronic Toxoplasmosis (Infectious) Other Weightloss Pyrexia Poorly regenerative anaemia CK elevated (180X upper ref.) Elevated liver enzymes Cardiomegaly Explains secondary symptoms and disease 18. Initial Treatment Pyrexia & Liver: IV fluids (0.9% saline) Neutropaenia and Bronchitis: Augmentin 40 mg slow IV TID, then oral Synulox 50 mg BID Toxoplasmosis: Clindamycin 25 mg BID 19. 5-days Post-Treatment 20. Continued Treatment & Monitoring Clindamycin 25 mg BID for 4 weeks Retest Toxoplasma antibody levels in 4 weeks Recheck biochemistry and haematology Ensure pulmonary infection has resolved and hepatic markers are within normal limits Consider further cardiac evaluation 21. Toxoplasma gondii Worldwide zoonosis Obligate, intracellular parasitic protozoan Only sexually reproduce in cats the definitive host Chronic infection can occur for the lifetime of the host, periodically rupturing cysts and re-encysting to increase numbers 22. Clinical Signs General Signs Anorexia Lethargy Pyrexia Weightloss Ataxia Specific Disease Bronchopneumonia Hepatitis Myocarditis Encephalitis Uveitis Acute or chronic progression Transplacental infection most severe Poorer prognosis with hepatic or pulmonary signs 23. Life Cycle 24. Questions? Special thanks Kate Stalin Rodrigo Gutierrez Quintana Emma Roberts Katie Grove