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This article was published in 1983
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Haemophilia in Cattle
A.G. Morton, B.V.Sc., Veterinary Inspector, GUNDAGAI
For many years a partnership experienced light losses of Hereford calves within 24 hours of castration by knife. Following the dissolution of the partnership and distribution of the herd, one owner found himself with a problem mob as tabled below:
| YEAR | MOB | MOB SIZE | DEATH | COMMENTS |
|---|---|---|---|---|
| 1979 | A | Unknown | 5 | All dams of affected calves culled |
| B | Unknown | 0 | ||
| 1980 | A | Unknown | 4 | Two dams of affected calves culled |
| B | Unknown | 0 | ||
| 1981 | A | 33 | 3 | Three dams of affected calves culled |
| B | 25 | 0 |
Mob A were herefords and had been joined to the same bull for all three calvings, while Mob B was a group of shorthorn and shorthorn cross cows joined to a different bull.
It was not until the 1981 episode that the owner sought assistance. Post-mortem examination revealed exceptionally pale mucous membranes and massive amounts of blood in the peritoneal cavity and/or excessive amounts of blood on the inner surface of the hind limbs. Surprisingly, for a condition which was later to be confirmed as a clotting disorder, there was no evidence of subcutaneous bruising.
Mob A was joined to a different bull for the 1982 calving. This was to prove futile in preventing the past castration losses.
At the first marking in 1982, twelve male calves were ear-marked and the time for clotting recorded. Bleeding from the ear-marks ceased within six minutes in all calves. This was a crude and generally unsatisfactory method due to the variability in the size of vessels severed and the tendency of the calves to shake their heads and dislodge partially clotted blood. Estimates of clotting time using the lead shot method found that the clotting times for ten calves were between 123 and 175 seconds, while two calves had longer clotting times, i.e. 225 and 273 seconds respectively. All twelve male calves were castrated with a knife and the two calves with extended clotting times were observed to bleed profusely. Both died within twelve hours.
According to human texts, classical haemophilia, a sex linked defect in factor VIII, is characterised by similar findings to those recorded above.
At the second marking in 1982, several male calves were sampled. Using the lead shot method clotting times were measured and found to vary from 138 to 200 seconds for six calves, while that of the seventh calf was 339 seconds. The seventh calf was spared from the unhappy fate of his companions. Tests were also undertaken to determine partial thromboplastin (PTTK) and prothrombin times. PTTK times were 47 to 79 seconds for six calves and 95 seconds for calf seven. PT times were from 35 to 43 seconds for all seven subjects.
Further assays of samples from calf seven revealed that this calf had 8% of the normal level of factor VIII, 40% of the normal level of factor 1X & 43% of the normal level of factor X1. The low level of factor VIII is consistent with a diagnosis of Haemophilia A. Decreased levels of factors 1X and X1 may exacerbate the haemorrhagic tendency
At the same time as this problem was being investigated at Gundagai, Veterinary Officer Bega was reporting similar findings in his district and the condition is now known or suspected in four herds.
Calf seven, and the three dams of affected calves are now enjoying the polluted air of Glenfield and the company of other haemophiliacs and carriers in Peter Healy's 'Genetic Cripples' herd. It is hoped to determine the mode of inheritance of this condition.
It is believed that these are the first known cases of haemophilia of cattle in the world.