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.
Dystocia and calving-related injuries
Another of the causes of lameness in calves and young stock is trauma. Specific injuries may include fractures, dislocations and other lesions involving ligaments, tendons and muscles. “Some of these may occur as a result of calving assistance associated with dystocia,” Shearer notes. “In situations where forced extraction of the fetus is required for delivery, avoid the use of excessive force and be sure to properly position obstetrical chains on the extremities to prevent possible injury.”
In cases where recovery is delayed or does not progress favorably, it may be due to irreversible damage of the vascular supply in affected tissues. When traction is applied at two points (above and below the fetlock) on the leg as opposed to one (traction on the foot at a point below the fetlock), the potential for fracture is reduced.
Closed fractures can be handled nicely with a cast or in some cases a splint fashioned from PVC pipe or other material, Shearer suggests. Changing of the splint or cast at three weeks with complete removal at six to seven weeks is usually sufficient. Generally speaking, closed fractures that are properly stabilized carry a very good prognosis.
Another condition associated with dystocia, particularly “hiplock,” is femoral nerve paralysis. Calves affected with femoral nerve damage tend to “squat” rather than stand normally. Some calves will spontaneously recover. A higher than normal incidence of dystocia and calving-related injuries should precipitate a review of calving assistance procedures. In some cases, intervention is occurring too early in the labor process. This has the potential to result in injury to the cow as well as the calf.
Injection site paresis
Generally speaking, intramuscular injections in neonatal or very young calves should be avoided as much as possible. Most calves simply do not have sufficient muscle mass to accommodate intramus-cular injections. Intramuscular injections in the hip (or gluteal muscles) may result in temporary or even permanent paresis in calves as a result of damage to the sciatic nerve and its distal branches. Damage to the sciatic nerve or its lower branches will cause calves to knuckle or walk on the anterior aspect of their pasterns.
“Studies also show that intramuscular injections in calves also contribute to reduced carcass quality at slaughter,” Shearer says. “Intramuscular injections increase trim losses and reduce meat tender-ness even when these injections occur in calves.”
Though you can’t find studies that have specifically looked at the incidence of lameness in beef ver-sus dairy calves and heifers, Shearer believes the incidence is greater in dairy calves because of the problems associated with colostrum deprivation and septicemias resulting in infectious arthritis. “However, commingling of either beef or dairy calves at weaning and beyond increases problems with other infectious agents such as Mycoplasma that are also associated with arthritis conditions in grow-ing animals.”
Feed calves for good feet
Calves and growing animals need an appropriate balance of nutrients to support growth. This in-cludes protein and energy levels appropriate for the size and age of animals in question, along with supplements to provide balanced support of vitamin and mineral needs. Vitamins and minerals have key roles in the formation of claw horn in cattle, says Jan Shearer, DVM, MS. “Biotin, in combination with calcium and trace minerals, has a key role in the growth and development of claw horn.”
Calcium is required for proper differentiation of cells in the germinal layer of the epithelium that are destined to become hoof horn. Trace minerals function in a variety of biochemical pathways respon-sible for the proper keratinization of epidermal cells. When the keratinization process is optimized, horn cells achieve the maximum in resistance to physical and mechanical forces imposed by external forces. “To this extent these are vital nutrients for the proper growth and development of hoof horn,” Shearer adds.
Genetic diseases of the limbs
Other feet and leg conditions of newborn calves that may have a genetic component include mule foot, polydactylism, dactylomegaly, marfans and osteogenesis imperfects (OI), a type 1 collagen de-fect. “The marfans and OI can present as weak pasterns,” Steffen says.
It’s not always possible to tell if feet and leg problems are genetic. Steffen says some tip-offs in-clude:
- The problem is limited to a family line and occurs on diverse environments (more than one herd).
- All unrelated cohorts in the same environment are normal.
- It is similar to genetic disease in another species.
- There is a consistent symmetrical pattern.
- Segregation frequency (estimating ratios of normal and recessive alleles when animals are bred).