Bovine Perinatal mortality

Rob Foster

University of Guelph

General Approach

The definition of perinatal mortality varies. It is common to define it as death within 48 hours of birth. In general, stillbirths animals are excluded from this category and a discussion on stillbirths can be found in the section on Failure of Pregnancy.

There are reviews of neonatal mortality - that cover diseases in the first month or months of life, but which were not related to the period around en utero or parturition.


Mee JF. Invited review: Bovine neonatal morbidity and mortality-Causes, risk factors, incidences, sequelae and prevention. Reprod Domest Anim 2023; 58 Suppl 2: 15-22.

Mortality rates

General surveys

Perinatal mortality of dairy animals is between 2 and 11%.

Mee et al (2008) studied the records of calvings in Ireland and there were 182,026 full term calvings. First calf heifers had a 7.7% perinatal mortality rate, and multiparous cow had 3.5% rate for an average of 4.29%. Dystocia was more prevalent in first calf heifers. Cows with perinatal mortality one year were more likely to have perinatal mortality the following year. Most cases occur within 1 hour of calving, and these are mostly from dystocia. In this study, stillbirth appears to be included in perinatal mortality.

Walder et al (2013) found in their study of 1155 calves that were perinatal mortalities that 12% had no identifyable cause. 10 had pneumonia, 10% had myopathy. 9% had cardiac disease, 8% had trauma, 7% were septic, 6% had developmental anomalies, 10% died of dystocia, 5% of hypothermia, 4% of goitre, 3% had aspiration pneumonia, 2% enteritis, 1% heart failure, and 1% abomasitis.

Mee et al (2013) performed a study to specify the criteria used to assign a cause of death to perinatal mortalities and recognised that standardisation was needed as there was disparate ways of defining a cause of death amongst veterinarians.

Raboisson et al (2013) found that mortality up to 2 days of age was 6.7% in dairy calves.

Cuttance and Laven (2019) reviewed the literature on perinatal mortality in calves and found that the inclusion criteria varies a lot - some defined it as death to 24 or 48 hours, many included stillbirths and seldom was premature parturition excluded. Overall it appeared that the mortality rate was about 6.2% and stillbirths were included in perinatal mortality. They concluded that very careful analysis of the literature was necessary if one group was to be compared to another.

Cuttance and Laven (2019) found that the risk factors for perinatal mortality were calves that are male, have primiparous dams, are twins or calving was assisted.

Norquay et al (2020) reported in perinatal mortality in beef herds in Orkney. They examined 1059 calves and found an overall incidence of 1.2% for non stillbirth mortality. The range was 0-2.6%. Congenital malformations, parturition related deaths and infection were the most common.



Cuttance E, Laven R. Estimation of perinatal mortality in dairy calves: A review. Vet J 2019: 252: 1053-1056

Cuttance E, Laven R. Perinatal mortality risk factors in dairy calves. Vet J. 2019; 253:

Mee JF, Berry DP, Cromie AR. Prevalence of, and risk factors associated with, perinatal calf mortality in pasture-based Holstein-Friesian cows. Animal. 2008; 2: 613-620.

Mee JF, Sanchez-Miguel C, Doherty M. An international delphi study of the causes of death and the criteria used to assign cause of death in bovine perinatal mortality. Reprod Domest Anim 2013; 48: 651-659.

Raboisson D, Delor F, Cahuzac E, Gendre C, Sans P, Allaire G. Perinatal, neonatal, and rearing period mortality of dairy calves and replacement heifers in France. J Dairy Sci. 2013; 96: 2913-2924.

Norquay R, Orr J, Norquay B, Ellis KA, Mee JF, Reeves A, Scholes S, Geraghty T. Perinatal mortality in 23 beef herds in Orkney: incidence, risk factors and aetiology. Vet Rec. 2020; 187: 28.

Noninfectious Causes of Mortality


According to Mee et al (2013) the agreed upon definition for anoxia is haemorrhage, meconium staining, organ 'congestion' and cyanosis.


Hypovitaminosis A

Deficiency of vitamin A in cattle is uncommon and usually only occurs in areas where the feed is dry and of poor quality. Calves are born dead or blind. Blindness occurs because of bony changes in the optic canals that are narrowed and cause Wallerian degeneration of the optic nerve.

Retinal atrophy and the lack of rhodopsin production are other reasons for blindness in vitamin A deficiency.


van der Lugt JJ, Prozesky L. The pathology of blindness in new-born calves caused by hypovitaminosis Onderstepoort J Vet Res. 1989; 56: 99-109


Colonic infarction

Adaska et al (2017) examined 34 calves with infarcts of the cecum. They were less than 30 days old and some were less than 5. The lesion is a descrete region of necrosis of the cecum usually at the midpoint and at the antimesocolic side. Despite extensive testing for enteric pathogens, no cause was found.


Adaska JM, Moeller RB, Blanchard PC, Aly SS. Cecal infarction in neonatal calves. J Vet Diagn Invest. 2017; 29: 242-244.



Calves derived from cloning are more likely to suffer stillbirth and perinatal mortality. Congenital defects including limb deformities are common. Of 31 calves in the study by Brisville et al (2013) 4 were stillborn and 5 had congenital defects. 14 took a long time to stand.

Brisville AC, Fecteau G, Boysen S, Desrochers A, Dorval P, Buczinski S, Lefebvre R, Helie P, Blondin P, Smith LC (2013). Neonatal Morbidity and Mortality of 31 Calves Derived from Somatic Cloning. J Vet Intern Med 2013; 27: 1218–1227


Encephalopathy - neonatal encephalopathy

Bianco et al (2017) reported on 58 cases of neonatal encephalopathy from 200 neonatal animals admitted for disease after parturition. Dystocia, male sex, abnormal position in the birth canal, and prolonged labor were the risk factors, but orientation of the calf in the birth canal was the sole factor in multivariable analysis.

Bianco AW, Moore GE, Taylor SD. Neonatal Encephalopathy in Calves Presented to a University Hospital. J Vet Intern Med 2017; 31(6): 1892-1899.

Inherited diseases

There are many inherited diseases that result in failure of pregnancy and perinatal mortality. The Online Mendelian Inheritance of Animals provides a database of inherited diseases.

Skeletal diseases

There are many diseases that are inherited and some may be responsible for perinatal mortality. These are reviewed by Dittmer and Thompson (2015).

Bulldog chondrodysplasia - Dexter cattle

Angus dolichocelphalic long nosed dwarfism - angus cattle

Ellis van Creveld syndrome 2 - Japanese brown cattle, Grey Alpine cattle

Arachnomelia - Italian brown, Simmental, German Fleckvieh, Brown swiss

osteopetrosis with gingival hamartomas - Belgian Blue

osteopetrosis - red angus

marfan syndrome - Japanese black cattle

Complex vertebral malformation - Holstein cattle

Brachyspina - Holstein - Friesan

Syndactyly - Holstein - Friesan, Simmental

Tibial hemimelia - Galloway, Shorthorn, Maine-Anjou

Dittmer KE, Thompson KG. Approach to Investigating Congenital Skeletal Abnormalities in Livestock. Vet Pathol 2015; 52: 851-861.



Microscopically visible anomalies

Anomalies not visible



Animals with dystocia are identified as having greater amounts of subcutaneous hemorrhage than non assisted calves. Edema of the face and tongue is also found. Dystocia is one of the most modifiable risk factors for perinatal mortality.


Mee JF, Sánchez-Miguel C, Doherty M. Influence of modifiable risk factors on the incidence of stillbirth/perinatal mortality in dairy cattle.Vet J 2014; 199: 19-23.


Jacinto et al (2021) reviewed the literature. This is a summary

Gingival vascular hamartoma

Cardiac vascular hamartoma

Pulmonary vascular hamartoma

Fibrous vaginal hamartoma

Nasal hamartoma of palate

Pulmonary hamartoma

Pulmonary choristoma

Nasal choristoma

Dermoids of eye

Jacinto JGP, Bolcato M, Sheahan BJ, Muscatello LV, Gentile A, Avallone G, Benazzi C. Congenital Tumours and Tumour-Like Lesions in Calves: a Review. J Comp Pathol 2021; 184: 84-94.

Haemorrhagic disorders/diathysis

There are many different causes for hemorrhage and death in neonates. Bovine neonatal pancytopenia is one well known entity. Others include septicaemia, Drug intoxications with chloramphenicol and furazolidone, bovine virus diarrhoea virus infections, Intoxications with rodenticides, mycotoxins, plants, trichloroethylene, thrombocytopathyof Simmental and other hereditary thrombopathy, leukosis, haemangioma, parafilariasis and idiopathic

Stoll A, Pfitzner-Friedrich A, Reichmann F, Rauschendorfer J, Roessler A, Rademacher G, Knubben-Schweizer G, Sauter-Louis C. Existence of bovine neonatal pancytopenia before the year 2005? Retrospective evaluation of 215 cases of haemorrhagic diathesis in cattle. The Vet J 2016; 216: 59-63

Bovine neonatal pancytopenia

Breed associated

Simmental cattle are known to have a platelet function disorder that results in prolonged episodes of bleeding including epistaxis and haematoma formation (Searcy and Petrie, 1990).

Searcy GP, Petrie L. (1990) Clinical and laboratory findings of a bleeding disorder in Simmental cattle. Can Vet J 1990; 31: 101-103.


According to Mee et al (2013) the diagnosis of hypothermia in calves is much more difficult than in lambs, presumably because they succomb more rapidly and dont metabolise their fat stores. A lack of colostrum intake (or evidence of suckling) combined with history, wet conditions, and inability to stand are the criteria.

Intrauterine growth retardation

The classical lesion of IUGR is growth arrest lines at the metaphysis. If these are not present, immaturity is used (Mee et al 2013).



Jacinto et al (2021) reviewed the literature. This is a summary

Desmoid fibromatosis


Infiltrative lipoma

Fibrolipoma of retroperitoneum

Embryonal rhabdomyosarcoma of skin

Lingual intramuscular myxoma




Multicentric lymphoma

Cutaneous mast cell tumor

Schwannosis (?)




Sustentacular cell tumor of testis

Interstitial cell tumor of testis


Yolk sac tumor

Embyronal carcinoma





Jacinto JGP, Bolcato M, Sheahan BJ, Muscatello LV, Gentile A, Avallone G, Benazzi C. Congenital Tumours and Tumour-Like Lesions in Calves: a Review. J Comp Pathol 2021; 184: 84-94.


Premature placental separation

According to Mee eet ao (2013), include emergence of the placenta with the calf, attachment of the placenta to the calf, fetal autolysis and several other indirect indicators.


The criteria according to Mee et al (2013) includes les than full term gestational age adn proportionally small body size and organ immaturity.


Trauma and dystocia are linked, but not all trauma is from dystocia.

Schuijt G (1990) studied newborn calves with fractures of the ribs and vertebrae and found a high correlation of vertebral fractures of the thoracolumbar area with forced extraction, especially in hip locked calves. Smaller calves were more susceptible.

Iatrogenic trauma occurs when there is assisted traction at birth. Fracture of the femoral head and proximal diaphysis occur, but there are circumstances when distal femoral fracture occur, especially if there is premature engagement of the stifle in the birth canal during assisted traction.(Ferguson 1994)

Ferguson JG (1994). Femoral fracture in the newborn calf: biomechanics and etiological considerations for practitioners. Can vet J 1994; 35: 626-630

Schuijt G. Iatrogenic fractures of ribs and vertebrae during delivery in perinatally dying calves: 235 cases (1978-1988). J Am Vet Med Assoc 1990; 197: 1196-1202.




Meconium aspiration syndrome

Many people believe that the fetus normally inhales amniotic fluid. This dogma was questioned many years ago and Lopez and Bilfelt (1992) wrote a paper about meconium aspiration syndrome where this belief was debunked. It makes absolutely no sense to me to have a fluid containing keratin within the trachea or pulmonary parenchyma. When fetus is our distressed presumably from hypoxia, they will gasping and inhale amniotic fluid. If sufficient, this will result in death soon after birth. With lesser amounts there will be inflammation with a mild alveolitis. Aspirated material will be visible within alveolar sacs stop this produces random focal regions of atelectasis. Death within the first 48 hours usually occurs if there is marked aspiration, but there is a second wave several weeks later with the secondary effects of alveolitis.


Lopez A, Bildfell R. (1992) Pulmonary inflammation associated with aspirated meconium and epithelial cells in calves. Vet Pathol 1992; 29: 104-111.

Neonatal encephalopathy

The clinical syndrome of neonatal encephalopathy in calves follows that of foals. Affected calves have a history of dystocia, particularly one of positional abnormalities and have nervous signs.

Bianco AW, Moore GE, Taylor SD. Neonatal Encephalopathy in Calves Presented to a University Hospital. J Vet Internal Med 2017;




Round cell




Congenital melanoma has a sporadic occurrance. Winslow et al (2017) reports on a case. It was of the skin of the flank fold and was amelanotic. It was highly metastatic.


Winslow CM, Wood J, Gilliam JN, Breshears MA. Congenital amelanotic melanoma in a crossbred heifer calf. J Vet Diagn Invest 2017; 29: 544-547


Nutritional diseases

Poor diets in cattle result in poor pregnancy outcomes. Some are attributed to deficiency of micronutrients, others to overall energy or protein/nitrogen availability. An overall reduction in the food intake by the mother, particularly if severe, will result result in a lower birth weight.
Over nutrition can result in a higher birth weight and lead to dystocia.

Silage diets are often listed and corn silage is a common theme. Syndromes include musculoskeletal diseases of various kinds, congenital white muscle disease


Energy/protein deficiency

Micronutrient deficiency

There are many syndromes where deficiency of specific nutrients are suspected.

Iodine deficiency

Classical iodine deficiency causes goitre.

Manganese deficiency

Ribble et al (1989) reported on a syndrome of congenital joint laxity and dwarfism that was seen in calves from cows fed silage over winter.

Valero et al (1990) attribute a high prevalence of chondrodystrophy in a Charolais herd (32 calves from 4 different sires) to manganese deficiency. The animals were on a diet of apple pulp and corn silage. The calves were typical in having short legs and large joints. They improved with age.

Hidiroglou et al 1990) considered a syndrome of congenital joint laxity and dwarfism in calves to be related to bioavailability of manganese in silage as a cause of this syndrome.


Ribble CS, Janzen ED, Proulx JG. (1989) Congenital joint laxity and dwarfism: A feed-associated congenital anomaly of beef calves in Canada. Can Vet J 1989; 30: 331-338.

Hidiroglou M, Ivan M, Bryan MK, Ribble CS, Janzen ED, Proulx JG, Elliot JI. (1990) Assessment of the role of manganese in congenital joint laxity and dwarfism in calves. Ann Rech Vet 1990; 21: 281-284.

Valero G, Alley MR, Badcoe LM, Manktelow BW, Merrall M, Lawes GS. (1990) Chondrodystrophy in calves associated with manganese deficiency. NZ Vet J 1990; 38: 161-167.

Infectious Causes of Mortality

The newborn calf is born immunologically niave or close to it. They soon encounter organisms that will become part of their normal biome and also pathogens. Colostrum provides valuable passive immunity including immunoglobulins, cytokines and immune cells (colostral cells).

The use of frozen colostrum can reduce or prevent the effectiveness of colostral cells and pasteurisation can denature cytokines and other proteins. This renders the calves less able to respond immunologically.

Gonzalez DD, Dus Santos MJ. Bovine colostral cells-the often forgotten component of colostrum. J Am Vet Med Assoc 2017; 250(9): 998-1005.


The newborn calf is exposed to environmental bacteria . It is believed that the initial attempts to suckle result in oral contamination. Excessive contamination of the legs or mammae of cows will result in greater than usual exposure to environmental organisms. This, combined with a failure of adequate passive transfer of colostrum will result in bacteremia.

In a study of neonatal calves in a large calf raising facility in California, Fecteau et al (1997) found that of 21 normal calves, none had bacteremia. Sick calves with either diarrhea or lethargy were sampled and 31% were bacteremic. Monomicrobial infections were the norm. Escherishia coli was the most prevalent (51%) and other gram negative enterics were next at 25.5%. Mortality was 57%.

Fecteau G, Van Metre DC, Paré J, Smith BP, Higgins R, Holmberg CA, Jang S, Guterbock W.(1997) Bacteriological culture of blood from critically ill neonatal calves. Can Vet J 1997; 38: 95-100.

Histophilus somni

Cows with genital infection (natural and experimentally induced) with Histophilus somni (previously Haemophilus somnus) are more likely to have weak calves (weak calf syndrome)

Waldhalm DG, Hall RF, Meinershagen WA, Card CS, Frank FW. (1974) Haemophilus somnus infection in the cow as a possible contributing factor to weak calf syndrome: isolation and animal inoculation studies. Am J Vet Res 1974; 35: 1401-1403.

Chromobacterium volaceum

Ajithdoss DK; Porter BF; Calise DV; Libal MC; Edwards JF (2009) Septicemia in a Neonatal Calf Associated with Chromobacterium violaceum. Vet Pathol 2009; 46: 71-74


Bovine herpesvirus 1

BHV-1 is a cause of failure of pregnancy at any stage. It can also cause perinatal mortality. Vaccination of dams with live vaccine or vaccination of newborn calves with BHV-1 vaccines can also cause perinatal mortality from systemic herpesvirus disease (Bryan et al 1994).


Bryan LA, Fenton RA, Misra V, Haines DM. (1994) Fatal, generalized bovine herpesvirus type-1 infection associated with a modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine administered to neonatal calves. Can Vet J 1994; 35: 223-228.


Any of the fungi causing failure of pregnancy could cause early embryonic mortiality. These are some examples reported

Lawhon reported on a calf that was premature and had dermatitis and abomasitis from which Saksenaea erythrospora (Order Mucorales) was recovered.


Lawhon SD, Corapi WV, Hoffmann AR, Libal MC, Alvarez E, Guarro J, Wickes BL, Fu J, Thompson EH, Sutton DA. In utero infection of a calf by Saksenaea erythrospora resulting in neonatal abomasitis and dermatitis. J Vet Diagn Invest. 2012; 24: 990-993.




Mee JF, Berry DP, Cromie AR. (2008) Prevalence of, and risk factors associated with, perinatal calf mortality in pasture-based Holstein-Friesian cows. Animal 2008; 2: 613-620.