Swollen Legs

This is a loosely defined term given to swelling of one or more legs seen in cattle at sea. Swollen legs are generally the result of accidental injury with or without secondary bacterial infection. Swollen legs and lameness represent one of the most common conditions affecting cattle during export voyages. 

Animals may be injured as a result of accidents during transport or loading, being stepped on by a pen mate, or from abrasion of the feet or lower limbs from contact with the deck or other hard surfaces. Anatomical areas that are commonly affected, and where initial swelling will be seen if detected early, are the fetlock, pastern or coronet region of the lower legs. 

Deck surfaces can be rough and abrasive. As the voyage progresses and there is increased accumulation of faecal matter on the floor, abrasions and minor wounds, or injuries of the feet or lower limbs may easily become infected. 

Cattle recumbent in crowded pens are always at risk of injury from being stepped on, especially the legs. All legs are at risk, but especially the hind legs, as they may be less likely to be tucked under a recumbent animal than the front legs. The number of swollen legs from this cause increases when pens are crowded with nervous, tired cattle. Cattle on slippery flooring or pens of cattle that push for feed are more at risk of developing skin abrasions or worn hooves creating an entry point for bacterial infection. 

Initial injuries may be small and innocuous, but over time there is a risk of mild injuries being exacerbated by repeated insult, and contaminated from exposure to faecal matter on the floor. A localised cellulitis may develop and result in swelling and lameness. Infection may involve distal joints, depending on the site and extent of the initial abrasion or injury. If the cellulitis progresses, the swelling becomes extensive, there is incapacitating lameness or toxaemia, and the animal dies or must be euthanised. 

Lame animals may have difficulty standing and moving and this, in turn, can lead to dehydration and inappetence, and may predispose animals to a range of other conditions, including heat stress. 

Swollen legs may also be due to joint infection secondary to bovine respiratory disease (BRD). 

Complications from swollen legs are one of the major causes of direct and indirect loss of animals at sea. The condition can result in death directly or lead to euthanasia. It can indirectly predispose animals to the development of other conditions. Leg complications can also result in rejection during health inspections at destination.

Swelling of the coronary band and pastern may occur with diseases of the claw, such as excessive wearing of the sole, sole bruising, toe abscess, sole abscess, and white line disease; or diseases of the interdigital space such as foot rot. However, these conditions are accompanied by moderate to severe lameness and the claws are spread. 

At necropsy, there is oedema and dark, mixed discolouration of subcutaneous tissues in the area of the swelling. A discharging skin wound may be present.

Move affected animals to a hospital pen with fresh bedding to reduce environmental contamination. 

Administer a course of antibiotics (procaine penicillin, oxytetracycline, or ceftiofur) and non-steroidal anti-inflammatory drugs (flunixin meglumine, ketoprofen, meloxicam, or tolfenamic acid) and once finished, recheck the animal for relapse. 

Avoid long-acting penicillins and glucocorticosteroids.

Low stress handling practices during loading and discharge will reduce the incidence of injury. 

Because early intervention saves lives, inspect cattle as soon as possible after loading and isolate and treat any animals that have lower leg wounds or swelling. During the voyage, all lower legs should be systematically scanned twice daily. This is best done immediately before or soon after feeding has commenced when most cattle will be standing up. Swollen legs are most easily detected after deck washing – ensure a scan of legs occurs immediately after deck washing and before spreading of sawdust when cattle will start to lie down.