by A. Rock
Dr. Earl Gaughan, DVM, DACVS, recently presented The Horse With Colic: What Do We Do? in Lowville, NY. Symptoms and possible causes were covered in Part 1 in the May edition of Mane Stream. Part 2 continues with the exam.
For the physical exam of an ill horse, safety first — though one has to know a sedative drug could change the exam data. Check for normal temperature, which can range 3 degrees, depending upon weather and activity . Heart rate is more important. Normal resting heart rate is 28-44 beats/minute. For a horse with colic 60 beats/minute, sustained, is the “hallmark” for colic. “This is a huge number,” says Dr. Gaughan, “It is a key to pain and shock syndrome.” Also, one needs to look at vital signs. The gums’ mucous membranes are “the window to the heart.” CRT or Capillary Refill time “should be less than 3 seconds, a lot less,” explained the good doctor. Toxic problems are evident at the gums; a finger print means the horse is in trouble. Aggressive action is needed.
For the exam, listening to the heart, lungs and abdomen are crucial. With the abdomen, which has four quadrants, one has to determine whether sound is normal; is there any sound at all? One would also “flick” on the horse’s side for the sepem-on both sides.
In some cases, other exams are crucial. For the rectal exam 2/3 is unreachable. A tear in the rectum is possible. Also, the horse’s colon could turn out of position and thus blood vessels are constricted. Nephrophrenic entrapment is when the space between the spleen and the colon becomes a trap. In the case of a 3 year old Arab the colon snagged, “where it didn’t belong” on the spleen. Using the drug phenylephrine and working on the horse for 20 minutes so it got its own adrenalin surge saved the need for surgery.
Supportive exams, such as ultrasonography, laparoscopy, may be needed. Still, one can’t see into all of the horse due its size. The small intestine alone is about 70’. Here most of the contents are fairly liquid. Thus a “round look” signifies trouble.
Also, a belly tap, abdominocentesis, may be needed to pull out some peritoneal fluid for testing. “Normal fluids are clear, but yellow is not. The darker, the worse; could be pus at the darkest,” states Gaughan. An increase in volume, protein, or red blood cell count is an indicator of trouble.
Remember, too, “The GI track is a one way ticket,” states Gaughan. Colic can put a horse in a dangerous situation. The stomach is the normal secretory organ to move intake downstream. A horse’s stomach can rupture because it cannot vomit. Thus, a stomach tube may be used (nasogastric intubation).
Overall, alertness and careful assessment of the situation is crucial. With test results, “We have far more accuracy. Plus, we come a long way from taking two days to a few minutes,” he said.
Among other reminders from Dr. Gaughan is that in switching types of hay, as from prairie grass to timothy, only 1/4 of the new hay should be given for 4 days. This will take 2 weeks but is safe. To trailer a colicky horse, a slant load is preferred. A horse can lean on the side. Some take the divider out like a stock trailer. Sometimes the trailer ride itself is therapeutic! More than once a healthy horse has walked off after definite signs at home.
In the case of a 22 year old thoroughbred mare with acute onset of colic, indicators were a strangulated bowel and secondary distention. (One key is that horses 14 years and older have “the propensity” to form fatty tissues inside the abdomen which can twirl around the abdomen.) The bowel wouldn’t survive nor the horse without immediate decision for surgery or a humane end. Age, emotion, and costs become a factor.
Thus, Dr. Gaughan presented several examples of horses with colic and the results. Overall, it is wiser to be careful than not. Ideally, one should feed more frequent, smaller meals; have longer, frequent turn out time; decrease feed concentrates, and have more quality forage. One could slow food intake by adding chaff (chopped hay) to meals to decrease risk. “Not all are practical due to time constraints and resources, but any improvement helps, he urged.
With equine influenza virus (EIV), Dr. Craig Gaughan pointed out the symptoms and the need for regular vaccination. Among the signs of influenze are: depression, poor appetite, temperature, and nasal discharge. A normal equine trachea has cilia to move material up and out. With flu infected trachea most its surface defenses are gone.”
Young horses and horses in an area of population density are especially at risk. It circulates within horse populations all the time. Research at the University of California at Davis combined with Merck Animal Health. Among 5,000 samples is evidence of “significant increase” in EHV 4(Equine Herpes Virus) and EIV (Equine Influenza Virus) which has grown since 2012 and 2013. This is more than with rhinovirus or strangles or HV 1, 2, 5, explained Gaughan.
“The demographics of affected horses are changing, and now include a multitude of ages and riding disciplines.” Influenza is a major economic loss to the equine industry,” stated Dr. Gaughan. “There is a loss of training or riding days as one week of rest is recommended for every day of fever.”
For equine influenza Dr. Gaughan recommended Flu Avert, which is a modified-live (MLV), intranasal, replicating vaccine. He said, it is “less subject to the consequences of antigenic drift and continues to provide exceptional against clinically relevant influenza strains infecting horses in the U.S.”
In conclusion, guests in the crowded banquet room seemed impressed and pleased that they had attended Countryside Veterinary Clinic’s Spring Dinner. Dr. Stacie Kenyon DVM said she hoped a fall program sponsored by the clinic would help prepare owners and riders for the cooler weather.
by A. Rock