Dilutor {DL} – non-lethal
Symptoms: Carrier bulls or females when mated to black cattle can produce offspring with a haircoat that is grey, smokey or chocolate brown and red to be diluted to yellow. Calves are usually mouse grey, have short curly and sometimes sparse hair and lack normal tail switch development.
Hypotrichosis {HY} – non-lethal
Symptoms: Partial to almost complete lack of hair. Affected calves are often born with very short, fine, kinky hair that may fall out leaving bare spots or areas particularly susceptible to rubbing. The condition may vary in expression as the animal matures and is usually less noticeable in older animals. The haircoat colour will sometimes appear frosted or silverish. Tail switch may be underdeveloped.
Idiopathic epilepsy {IE} – lethal
Symptoms: Age of onset (occurrence of the first seizure) can be variable, ranging from birth to several months of age. Occurrence and persistence of seizures may be influenced by environmental stressors such as temperature extremes or increased physical activity. Upon initial onset of seizure episodes, individuals will typically lie on their side with limbs extended in a rigid state. Manual flexing of the limbs is possible, but return to the extended position occurs after release. Seizure episodes may last from several minutes to more than an hour.
Maple syrup urine {MSUD} – lethal
Calves are typically born without symptoms but by two to four days of age become slow, dull and eventually recumbent. The calves will often throw their heads back, lying on their side unable to rise. These calves may have some swelling of the brain at autopsy, but diagnosis requires laboratory investigation. The calves have a defect in an enzyme that breaks down complex amino acids in the diet and the build-up of these in the body creates the urine odour and brain damage. The disease name comes from the smell of urine observed in human babies (not always noted in calves).