Lameness was the second most prevalent disease on dairies behind clinical mastitis, as reported in the NAHMS Dairy Study 2007, and 16% of cows were permanently removed due to lameness. Though lameness is a big problem for adult dairy cows, little attention is paid to lameness in the calf.
The newborn calf’s feet are naturally very soft, in part because of the prenatal environment (inside the amnionic sac where the feet are immersed within the amnionic fluid), explains Jan Shearer, DVM, MS, University of Florida. “They gradually harden in the drier postnatal environment on land.”
Congenital joint and tendon deformities
There are several congenital defects characterized by joint fixation in calves. Many of these are se-vere enough to be lethal, whereas most others are life-threatening because they prevent the calf from mobility to nurse, find water, graze or flee from predation.
The most common congenital limb deformities are contracted tendons, congenital articular rigidity and athrogryposis. Of these, contracted tendons have the best prognosis, Shearer says, and mild to mod-erate cases will often recover spontaneously over the course of several days. “One of the biggest problems for calves is that contracture of the tendons often restricts their ability to nurse,” he says. “Thus, affected animals may be colostrum-deprived and have difficulty nursing without assistance.”
The disease is manifested by excessive flexion of the fetlock joints of the front feet, which causes affected animals to “knuckle” or walk on the anterior aspect of their pasterns. Although some have attributed the occurrence of this condition to restricted fetal space or a mal-positioning of the fetus in late gestation, the exact cause is unknown. Dave Steffen, DVM, PhD, Veterinary Diagnostic Center, University of Nebraska, notes that at least one source suggests that the cause is due to the expres-sion of an autosomal recessive gene.
Calves with severe contracture of the tendons may be treated with a splint or cast applied to the legs, maintaining them in extension for several days, but Shearer warns that these casts or splints must be monitored carefully for evidence of pressure sores. Putting the legs into extension helps the calf rise to nurse and increases its mobility by permitting limited exercise.
Infectious diseases in calves
Infectious arthritis is a frequent complication of septicemia in calves. Joints are painful and swollen,and affected animals are often quite unthrifty. Therapy is often unrewarding. “The single most impor-tant control measure is to ensure the timely intake of 3 to 4 quarts of colostrum,” Shearer says.
Depending upon severity, infectious arthritis conditions result in calves that develop more slowly or, in the worst case scenarios, calves that may need to be destroyed due to permanent damage of joint cartilage and chronic arthritis. The joints most often affected are the hock, knee (carpus) and stifle joints. “As with most diseases, when treatment is instituted early a successful outcome is possible,” Shearer says. “However, delays in identification and treatment create conditions that can be very dif-ficult to manage. Prevention is far more effective than treatment. Problem herds need to ensure co-lostrum intake and maintain a clean and dry calving area for cows at the time of parturition.”
Navel infections and joint ill (infectious arthritis) are consistent with septicemias in calves. Thus, na-vel dipping has become a routine health-management procedure in most dairy operations. “Although there is very little if any scientific evidence to support navel dipping as a means to prevent disease in neonates, the association between navel infection, infectious arthritis and septicemia encourages dairymen to include disinfection of navels in neonatal calf-care protocols,” Shearer explains.
Secondary involvement of joints may occur from septicemias arising from gastrointestinal (E. coli, Salmonella, etc.) or respiratory (Mycoplasma spp.) diseases, as well. Joints become warm and swol-len, with affected animals showing varying degrees of lameness.