b'STEP BY STEPlocation of swelling, the horses overall state of health, any history of previous limb swelling, and any recent manage-ment changes is information that helps your veterinarian assess over the phone whether the limb swelling requires imme-diate veterinary attention or can first be treated symptomatically and monitored. Here are five common diagnoses your veterinarian might make.1. Stocking UpStocking up describes swelling of the lower limbs (below the knees or hocks) in horses due to pooling of fluid (edema) in the tissues, says Cuming. Stocking up often occurs when horses undergo a period of restricted move-ment such as stall confinement, she says. A reduction in the normal physiologic pumping of fluid causes the lower limbs to swell. She likens it to swelling that might develop in your ankles following a long plane ride. A horses lymphatic system is always working to move fluid, proteins, and nutrients around the body. In the normal DUSTY PERINhorse, fluid, proteins, and nutrients fre-quently leak out of blood vessels to bathe the cells of the tissues with needed nutri- Cellulitis can cause swelling, heat, and lameness and typically affects a single limb, such as this ents, says Cuming. This fluid, togetherhorses left hind.with cellular debris, dead blood cells, bacteria, and other pathogens (disease- orlymphangitis (see next section) due toThe swelling causes significant lame-damage-causing organisms), toxins, andless-efficient circulation. The best thingness and fever and is usually in a single protein molecules, is then removed fromto do is to get the horse moving, she says.limb, says Randall. I have seen cases the leg via lymphatic vessels, which areActive exercise with hand-walking, longe- where multiple limbs were involved after thin-walled, valved structures capable ofing, or riding should resolve at least sometoo much time standing in nasty water containing large volumes of fluid. Theof the swelling. Support bandaging alsowhen horses were trapped for days in lymph fluid is filtered through the lymphhelps reduce swelling rapidly. However, iffloodwater after Hurricane Harvey in nodes and then returned to the blood- used too long, bandaging further reduces2017.stream via the veins.lymphatic and blood flow and can per- The affected limb is characteristi-There is no active pump (like thepetuate the condition. cally swollen, hot, and very painful to heart) in the lymphatic system, and sothe touch, with an associated moderate pressure and movement in the tissues and2. Cellulitis and Lymphangitis to marked lameness, adds Cuming. A organs around lymph vessels influenceSignificant and alarming limb swellingsmall number of horses, however, will flow, she continues. In horses loweris often due to cellulitis or lymphangitis.pull up lame without obvious limb swell-legs, movements of the hoofs digitalLimb cellulitis typically occurs acutely ing, and you only suspect cellulitis when cushion (the soft tissue beneath the solethe horse seems fine, then becomes lameyou feel heat and mild pitting edema that separates the frog and heel bulb fromsuddenly, says Cuming. Cellulitis is ain the lame leg. In addition to pain and the underlying tendons and bones), thediffuse bacterial infection of the skin andswelling, cellulitis may also cause a poor pasterns, fetlocks, ligaments, and tendonssubcutaneous tissues that dissects rapidlyappetite, lethargy, elevated heart rate, play an important role in helping toand extensively through tissue planes.fever, and oozing of serum from the skin pump lymph fluid up the lymphatic ves- Bacteria such as staphylococcal or strepto- of the swollen leg.sels against the force of gravity. coccal species enter a break in the skin Rapid recognition and early treatment While stocking up can occur in anysometimes youll see a wound, sometimesof cellulitis are important to avoid other horse, Cuming says veterinarians mostthe infections entry point isnt obvious,serious complications, such as supporting commonly see it in older horses or thosesuch as might occur if leg boots causelimb laminitis (founder in the opposite with previous leg injuries, cellulitis, ormicroabrasions in the skin, she says.or supporting leg), dermal necrosis (skin 44November 2019The Horse|TheHorse.comUntitled-20 44 9/25/19 9:54 AM'