1. This material is freely available for teaching and other non-commercial uses.
Milton M. McAllister
The article “Diagnosis and control of bovine neosporosis” is available at this link for free download for a limited time, until 7 August 2016

2. Fig. 1, from Diagnosis and Control of Bovine Neosporosis
Fig. 1, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister MM, 2016.
Fig. 1. Neurologic impairment in calves infected with Neospora caninum. The beef calf at left was born following a neosporosis abortion outbreak. It was undersized, had weak hindlimbs, and a conscious proprioceptive deficit that is here demonstrated by the dorsal placement of the left rear hoof. The dairy calf at right was unable to stand, maintain sternal recumbency, or elevate its head.

3. Neospora caninum protozoal life cycle
Latent microscopic cysts in tissues contain bradyzoites
tissues ingested
Asexual and sexual reproduction
Oocysts in canine feces
(10-11 µm)
exposure to air
Oocysts sporulate and disseminate in dust and water
Tachyzoites replicate intracellularly and spread to other cells
defecation
(N. caninum immunohistochemistry and modified Giemsa impression smears of canine intestine)
(immunofluorescent stain of cultured organisms)
oocysts ingested by
Intermediate Host
immune response
controls proliferation
by Definitive Host
(contrast illumination)
Fig. 2. Neospora caninum life stages. (upper left) Photomicrograph of a squash preparation showing a spherical, thick-walled cyst containing numerous bradyzoites; this latent stage survives in tissues for prolonged periods. (upper right) Asexual and sexual reproductive forms of the parasite that occur in canine intestine after ingestion of infected tissues. (right) Egg-like oocyst, shed in canine feces. (bottom right) Sporocysts containing sporozoites have developed within an oocyst, which is now infectious. (bottom left)Upon ingestion of infectious oocysts by an intermediate host animal, sporozoites are liberated by digestive juices, invade host cells, and become rapidly dividing tachyzoites; if unchecked by the immune response, tachyzoites may cause clinical disease. Otherwise, they convert to latent bradyzoites and the cycle is completed.
Fig. 2, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister MM, 2016.

4. Transmission of Neospora caninum.
Fig. 3. Transmission of Neospora caninum. Cattle may become infected “horizontally” by ingestion of oocysts at any time of life (not only when pregnant). Congenital infection may result if infection is first acquired by a dam during pregnancy (exogenous transplacental transmission), or by reactivation of organisms from a latently infected dam (endogenous transplacental transmission). Artist: Kerry Helms, University of Illinois.
Fig. 3, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister MM, 2016.

5. Relation between the time of maternal exposure to Neospora caninum oocysts and the outcome of pregnancy in naive cattle
Time of Exposure
First trimester
Second trimester
Third trimester
Fetuses on this side of the solid curve are infected, but are clinically normal if above the dotted curve
Fetuses below
both curves are aborted or impaired
Fetuses on this side of the curve have not acquired infection
No fetal immune system
Maturing fetal immune system
Pathogenicity
of Transplacental
to Fetus
Transmission
Low
High
Likelihood
Fig. 4. Relation between the time of maternal exposure to Neospora caninum oocysts and the outcome of pregnancy in naive cattle.
Fig. 4, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister MM, 2016.

6. A D C B Styrofoam container
Case sheet in bag protects clerical staff. Information assists diagnostics and reduces unnecessary phone calls for clarification.
Cold pack
Absorbent packing
Double-bagged specimens keep items sterile and prevent leaks.
Fig. 5. Submitting specimens for abortion diagnostics. (A)Wet specimens of any type should be packaged within 2 containers, an inner primary and an outer secondary container, with absorbent material in between. Here, absorbent material is placed in the bottom of a biological specimen bag (not a zip-closing sandwich bag) to provide reliable secondary containment. (B) Tightly closed primary specimen containers are suitable for formalin specimens or fresh tissues. (C) Vacuum serum tubes are suitable sterile containers to hold liquid specimens including abomasal fluid, fetal fluids from thorax or abdomen, and serum from the aborting dam. (D) A package ready to be sealed and shipped.
Fig. 5, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister MM, 2016.

7. F G E A B C D
Fig. 6. Potential contamination of feedstuffs with Neospora caninum oocysts and dissemination in mixed rations. Representative dairy (A–E) and beef (F, G) farms are depicted that each had a recent neosporosis outbreak. Clockwise from upper right: (A) Above ground ensiling practices increase the opportunity for rodents to frequent or inhabit the silage, especially at the leading edge and around the sides, where discoloration reveals that anaerobic conditions have not been adequately maintained. When examined, rats and mice were flushed out of the silage pile. Dogs and other canids are attracted both to open silage and to rodents. (B) Examples of ration components piled in open bays or outside at a large dairy farm. (C) Various components of the mixed ration. (D) Use of a front-end loader and mixer wagon to prepare a TMR. If any component is contaminated with Neospora oocysts (or other orally transmitted pathogens such as Leptospira or Salmonella), then it will become distributed throughout the TMR. (E) Feeding the TMR to a pen of dairy cows. Potential exists to deliver pathogens to many animals at a time. (F) This outdoor silage pile on a beef farm was not covered, and animal tracks and scats of many types were present, potentially increasing attractiveness to dogs and coyotes. (G) Provision of mixed silage and chopped hay to the beef cow herd, which were periodically brought in from winter pasture for supplemental feeding.
Fig. 6, from Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister MM, 2016.

8. Combined 1744 / 2762 63% Citation Year Location
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
Location
Seropositive offspring / Seropositive dams
Simple calculation of endogenous transmission rate
[66]
2004
Ontario
252 / 619
41%
[42]
2007
Netherlands
325 / 526
62%
[67]
2003
363 / 500
73%
[68]
2005
Sweden
316 / 369
86%
[46]
Costa Rica
168 / 285
59%
[45]
2001
163 / 204
80%
[69]
2000
Quebec
64 / 144
44%
[70]
1996
California
93 / 115
81%
Combined
1744 / 2762
63%
modified from Table 2 in: Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister, Milton M. 32:

9. were administered to cows
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
Number of cows that became infected and were followed to parturition 7 9
Number of offspring that became infected 3 6
Proportion of infected cows having infected offspring
0.00
0.33
0.86
Number of cows having abortions or stillbirths
Number of aborted fetuses or stillborn calves that were infected -
Proportion of infected offspring that were aborted or stillborn
1.00
Table 1 in: Diagnosis and Control of Bovine Neosporosis. Veterinary Clinics of North America: Food Animal Practice. McAllister, Milton M. 32:

10. Virus Protozoan Bacteria Phylum Apicomplexa Apical complex
Photo from: Duane’s Foundations of Clinical Opthalmology, Chapter 76, Ocular Toxoplasmosis, Holland & O’Connor
mitochondria
nucleus
without organelles
without cytoplasm

11.
wikipedia
Stage changes of insects are similar to stage changes that occur in Apicomplexan parasites

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

14. Tachyzoites
- multiply inside of host cells
- may cause disease

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

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

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

18. A cyst containing bradyzoites.
Squash prep from the brain of a laboratory mouse.
McAllister

19. Oocysts shed in canine feces resistant to environmental degradation
orally infectious to intermediate hosts O2
Nonsporulated oocyst
diploid
Sporulated oocyst
haploid

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

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