Lymphangitis is swelling and/or inflammation that is commonly a result of damage to the lymphatic drainage system. The lymphatic system is a network that carries lymph fluid to the thoracic duct and then to the bloodstream, where it is then circulated from there back into the tissues. Usually the damage is a bacterial infection or the effect of a toxin. If a bacterial culture is taken it may come back as a negative.
The symptoms of Lymphangitis can include:
- Severe swelling of a limb. This can cause the leg to double or triple in size in some cases, and can spread as far as the stifle, sheathe or udder (if in the hind).
- In the primary stages of the condition the swelling may present as a pitting oedema, which means that if it is pressed a depression will remain in the swelling. As the illness progresses to a chronic level much of the swelling may become firm, due to the formation of scar tissue.
- The swelling is quite painful and your horse may be sensitive to you touching it
- Often there will be a wound present, as this could be a possible entry point for the infection (even if the wound is very minor).
- Lameness may ensue as a result of the swelling, as this can be so severe as to appear that the horse has fractured a bone
- The horse may present a high temperature and fever-like symptoms as a result of infection
- In some cases an oozing discharge has been reported
- Skin damage & loss. The blood supply to the skin can be damaged due to the swelling, causing the skin to die. Therefore the dead skin would slough off (fall away). The degree of the skin that would be damaged may be a result of the timing and effectiveness of treatment.
Icing is recommended to help with swelling. We have seen cases where early and consistent icing treatment has significantly reduced the level of skin deterioration & damage. Treatment of Lymphangitis can also includes a course of penicillin (sometimes specific to the culture and sensitivity findings, if it was tested), and an anti-inflammatory drug. Steroids in more chronic cases may be used (and have been shown to be quite successful), though this treatment should be undertaken with caution as steroids can limit the horse’s ability to fight infection. If a wound is present this would also be treated, importantly to reduce further infection. Bandaging may be utilised by the vet to reduce swelling, though this must be monitored as the leg may swell further, causing excessive pressure to the leg and leading to bandage reactions and an exacerbation of symptoms. 
In some cases upon suspicion of Lymphangitis, x-rays and ultrasound may be used to rule out other initial causes, and also if abscessation is present, to help determine the extent of abscess pockets. A fluid sample may sometimes be taken for a bacterial culture and sensitivity also (though again, this may come back as a negative).
Preventing this scary condition can be a challenge for obvious reasons. It goes without saying that having a clean, debris-free paddock with good fencing may prevent injury and therefore wounds. There is evidence that insects such as spiders may also carry the bacteria or toxins and therefore infect the horse if they bite it. Rugging and spraying your horses with an insect repellent such as Flyaway would then be another helpful preventative tool. Some horses get recurring Lymphangitis annually, at around the same time, and this could be due to insect activity during this season. Immediate and effective veterinary attention should always be implemented to help prevent skin degradation. Sadly in some cases untreated lymphangitis can be fatal due to extreme levels of skin and tissue loss.
Please phone us on 5543 1213 or 0409 884 377 if you suspect Lymphangitis, or even if you horse shows swelling/lameness/high temperature but you’re suspecting another cause.
