This material is freely available for teaching and

This material is freely available for teaching and other non-commercial uses. Milton M. Mc. Allister milton. mcallister@adelaide. edu. au The article “Diagnosis and control of bovine neosporosis” is available at this link for free download for a limited time, until 7 August 2016 http: //authors. elsevier. com/a/1 TE 2 f_H 22 n 97 e. D

Fig. 1, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister MM, 2016.

(contrast illumination) Asexual and sexual reproduction (N. caninum immunohistochemistry and modified Giemsa impression smears of canine intestine) Latent microscopic cysts in tissues contain bradyzoites Neospora caninum protozoal life cycle (10 -11 µm) Oocysts in canine feces Oocysts sporulate and disseminate in dust and water Tachyzoites replicate intracellularly and spread to other cells (contrast illumination) (immunofluorescent stain of cultured organisms) Fig. 2, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister MM, 2016.

Transmission of Neospora caninum. Fig. 3, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister MM, 2016.

issio n Hi gh Relation between the time of maternal exposure to Neospora caninum oocysts and the outcome of pregnancy in naive cattle enta l Tr ansm Fetuses on this side of the curve have not acquired infection elih Lik w ty nici oge Path Lo h Hig ood of T rans plac Fetuses on this side of the solid curve are infected, but are clinically normal if above the dotted curve s tu No fetal immune system Fe First trimester to Fetuses below both curves are aborted or impaired Low Second trimester Time of Exposure Third trimester Maturing fetal immune system Fig. 4, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister MM, 2016.

A B Styrofoam container Absorbent packing Cold pack C Double-bagged specimens keep items sterile and prevent leaks. Case sheet in bag protects clerical staff. Information assists diagnostics and reduces unnecessary phone calls for clarification. Fig. 5, from Diagnosis and Control of Bovine Neosporosis. D Veterinary Clinics of North America: Food Animal Practice. Mc. Allister MM, 2016.

G A B F C E D Fig. 6, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister MM, 2016.

Table 2. Endogenous transplacental transmission rates of Neospora caninum in dairy cattle. Studies were included if they tested the offspring of at least 100 seropositive dams. These calculations have not been adjusted to account for horizontal transmission, which could cause upward skewing. Citation Year [66] [42] [67] [68] [46] [45] [69] [70] Location 2004 Ontario 2007 Netherlands 2003 Netherlands 2005 Sweden 2003 Costa Rica 2001 Netherlands 2000 Quebec 1996 California Combined Seropositive offspring / Seropositive dams Simple calculation of endogenous transmission rate 252 / 619 325 / 526 363 / 500 316 / 369 168 / 285 163 / 204 64 / 144 93 / 115 41% 62% 73% 86% 59% 80% 44% 81% 1744 / 2762 63% modified from Table 2 in: Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister, Milton M. 32: 443 -463. 2016.

Table 1. Results of administration of Neospora caninum oocysts to pregnant cows. Data were compiled from the only three published experiments of this type. Day of gestation that oocysts were administered to cows 70 120 – 130 162 - 210 Number of cows that became infected and were followed to parturition 7 9 7 Number of offspring that became infected 0 3 6 0. 00 0. 33 0. 86 Number of cows having abortions or stillbirths 0 3 0 Number of aborted fetuses or stillborn calves that were infected - 3 - Proportion of infected offspring that were aborted or stillborn - 1. 00 0. 00 Proportion of infected cows having infected offspring Table 1 in: Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. Mc. Allister, Milton M. 32: 443 -463. 2016.

without cytoplasm Virus without organelles Bacteria Apical complex Protozoan Photo from: Duane’s Foundations of Clinical Opthalmology, Chapter 76, Ocular Toxoplasmosis, Holland & O’Connor http: //www. oculist. net/downaton 502/prof/ebook/duan es/pages/v 8/ch 076/002 f. html nucleus mitochondria Phylum Apicomplexa

wikipedia Stage changes of insects are similar to stage changes that occur in Apicomplexan parasites wikipedia www. ottersandbutterflies. co. uk

Stages of Neospora caninum or Toxoplasma gondii Tachyzoites (like dividing caterpillars) Oocysts (eggs) Bradyzoites in cysts (crysallis in cocoon) Sexual forms (butterflies)

Tachyzoites - multiply inside of host cells - may cause disease

Necrotic focus rimmed by infiltrating leukocytes in the brain of an aborted calf Immunohistochemistry demonstrating tachyzoites (black) within a cerebral lesion Mc. Allister Tachyzoites in cell culture (fluorescent antibody label)

Typical lesions in aborted bovine fetus: nonsuppurative inflammation in epicardium, myocardium, muscle, and brain

Bradyzoites - “hibernate” within cells in muscle and CNS - infect the next animal by carnivorism

A cyst containing bradyzoites. Squash prep from the brain of a laboratory mouse. Mc. Allister

Oocysts - shed in canine feces - resistant to environmental degradation - orally infectious to intermediate hosts O 2 Nonsporulated oocyst Sporulated oocyst diploid haploid

Neospora caninum Nonsporulated oocyst Sporulated oocyst 10 μM This is the only diploid stage in the life cycle 10 μM Two sporocytes inside of the oocyst, each containing four haploid sporozoites Sporulated oocyst photo is from: Mc. Allister MM. , Dubey JP, Lindsay DS, Jolley WR, Wills RA, Mc. Guire AM. Dogs are definitive hosts of Neospora caninum. Int J Parasitol 28: 1473 -1478, 1998.

Photo from: Gondim L. F. P. et al. , Transplacental transmission and abortion in cows administered Neospora caninum oocysts. J Parasitol 90, 1394 -1400, 2004