Cattle can become afflicted with large swellings both as individual animals or on a herd basis. Diagnosing, treatment and prevention are key factors producers and veterinarians must consider.
Before proceeding, causes other than abscesses must be ruled out. Abscesses take time to develop so a sudden swelling may indicate another cause.
When that happens, a few circumstances involving the animal’s history must be explored.
First, the producer or the vet should clip the hair surrounding the swelling and thoroughly clean the area. This is called a sterile prep.
Then use a sterile needle to poke into the area and aspirate the contents. This provides information depending on what we get back.
If it is an abscess, pus will be present; if blood is present, it is evidence of a hematoma; if clear fluid is present it could indicate a seroma, and if peritoneal fluid or gut contents are found, it could indicate a hernia.
The procedure needs to be carried out in a very clean fashion to avoid introducing germs.
If it is a hematoma or blood blister, we want to leave the swelling to clot up. We don’t want to lance it because the animal may have a propensity to bleed or a bleeding disorder. Hernias may require surgery.
The seromas are often fluid-filled cysts seen in dairy cattle around the carpus (front knees) or tarsus (hocks). The free-stall designs and bedding used in dairy barns today have significantly reduced these types of swellings.
Some bulls get swellings around the hocks, which I call boggy hocks. They are an accumulation of excess joint fluid in the area.
The problem can be caused by various factors and often draining them only leads to a return of the fluid a short time later. These types of swellings are usually left alone. They are not painful and only occasionally cause a functional lameness.
Veterinarians are extremely cautious about tapping into these joints. They debate whether the problem is hereditary and may be due to a slight conformational problem with the angle of the hock joint.
In instances of abscesses, the situation will often be dealt with immediately. It is important that larger abscesses drain well and all the infective material is removed so the problem does not reoccur.
Once there is a firm diagnosis of an abscess, we may sedate the animal and/or freeze the area. It is necessary to lance the abscess on a dependent part if possible and leave the opening big enough so it will drain.
We only lance when there is evidence of pus right under the area we are to lance. The remaining pus is often flushed out with a flushing syringe or hose and pump.
Farmers can be fooled in cases involving the navel area when a hernia comes up beside an abscess.
Cattle have an amazing ability to wall off infections and we are fortunate that these infections seldom turn out to be a cellulitis, which is an infection that spreads through the musculature.
Lancing and good flushing of abscesses generally cure the problem. By flushing, I mean washing out the area with things like surgical soap or a diluted iodine solution.
If the cavity is very large, ancillary treatment with iodine-soaked kling can be put in to fill the area and a small amount of the kling is removed daily.
It is important to ensure drainage for a long time, so veterinarians will suture in a Penrose drain to facilitate draining, which is often removed after several days.
During fly season, it may also be necessary to control flies.
If a large swelling is properly removed, there is little chance of a blemish or reoccurrence.
It is important to treat abscesses carefully and, if in doubt, have a veterinarian check it first because lancing into a hernia can have fatal results.
Most swellings are not emergencies and treatment can be properly organized and planned into your schedule. The swelling will be greatly reduced and there should be no dockage at slaughter.
In cases of multiple abscesses or hematomas on several animals, one must look at potential causes.
Vaccinating with dirty needles or improper vaccination techniques, vaccinating in a rain storm or injuries from fences, gates or handling equipment can all cause abscesses on multiple animals.
Watch for sharp points because injuries can lead to bruising and swelling and these sites are more susceptible to abscesses.
Painkillers may be provided, but antibiotics are seldom necessary.
Try and remove and dispose of the pus immediately to avoid contamination of the area, and clean and disinfect the equipment used.
Roy Lewis works as a technical services veterinarian part time with Merck Animal Health in Alberta.