Diarrhoea in Adults

Larval cyathostomosis

In this condition worm larvae cause severe damage and inflammation to the large intestines. It is seen most commonly in younger horses between November and March. Affected animals will usually have a history of no or improper worming treatment. In some cases the disease can be seen after recent worming as, if the animal has not been wormed regularly previously and built up a large worm population, a huge inflammatory response can occur.

Veterinary advice should always be sought before worming any animal where the worming history is unknown. Wormers that can be given over a few days are usually used as the worming treatment can take place gradually.

Clinical signs

Affected horses will have weight loss, diarrhoea, swelling of lower limbs and brisket and may have a fever.

Diagnosis

The worm larvae can be seen when a sample of the droppings is viewed under a microscope.

Treatment

Horses require worming treatment to kill the larvae, a five day course of Fenbendazole, panacur equine guard, is often used followed by another wormer. Other As the intestines are damaged proteins can leak out causing there to be less in the bloodstream. This can cause a circulatory collapse so, in some cases, attempts must be made to boost protein levels as well as replace lost fluid. Larval cyathostomosis is a very severe condition and man animals don’t recover. If the treatment is successful it can still take many months for them to fully recover and gain weight. See section on worming advice.

Salmonella

Approximately 10-20% of all horses are carriers of salmonella without showing any signs. Other illness or disease, transport, hospitalisation and excessive work can potentially trigger signs of the disease. Horses become infected either from carriers, horses with the disease and the environment. Salmonella infection will usually follow one of the following routes:

  1. Enteritis. This is the most frequently seen form, with affected animals being very ill and having diarrhoea, signs of colic, high temperature, increased heart rate and toxaemia. These animals often require hospitalisation so that they can receive supportive therapy such as fluids to counteract the dehydration, flunixin, an anti-inflammatory drug, to try and prevent or counteract endotoxaemia. Polymixin B is occasionally used to neutralise endotoxins and antibiotics are given if the horse is septicaemic.A diagnosis can be made by culturing the bacteria from the droppings in a lab. The one problem with this is that the bacteria is not always shed so three negative samples are required to fully rule out the disease.
  2. Carrier state. As mentioned some horses show no signs of disease after they have come into contact with salmonella, however, disease can be triggered by stresses.
  3. Fever without diarrhoea. Some patients are off their food, depressed and have a high temperature but no diarrhoea. These can be teated with anti-inflammatory drugs, such as flunixin, and antibiotics.
  4. Septicaemia. This is a common outcome in foals and is where the bacterial infection is in the bloodstream and can infect other organs in the body such as the lungs, intestines and joints, joint ill.Affected foals will be ill with a high temperature and may be lame with a swollen joint or show respiratory signs or diarrhoea. A sample of blood can be cultured to find the exact bacteria causing the septicaemia. The main treatment is antibiotics, although other supportive treatments such as intravenous fluids may be required. Prevention of septicaemia can be done by measuring the level of antibodies, IgG, in the blood at approximately one day of age. These antibodies are aquired from the mother’s colostrum, first milk produced, and are required to fight off infection. If these levels are low, due to not receiving enough colostrums, plasma can be given intravenously to boost immunity. The foals naval should be sprayed with an antibacterial solution as early as possible and the environment kept clean.
  5. Small colon impaction. Occasionally horses get an impaction after infection. Affected animals will usually have mild colic signs with a normal heart rate and mucous membrane colour. There may be a reduction in the volume of the gut sounds and the number of droppings (these may also be firmer).The impaction is diagnosed by palpating it on rectal exam.Horses should be starved until the impaction has cleared and given plenty of water. The vet will pass a stomach to give large volumes of fluid to soften the impaction, laxatives such as liquid paraffin can be included (this often has to repeated). Pain killers are used to keep the horse settled. In persistent cases intra-venous fluids are also given.

Prevention of spread

All horses suspected of having salmonella should be placed in strict isolation to prevent spread to other animals and all equipment should be thoroughly disinfected.

Antibiotic induced diarrhoea

Antibiotic treatment can occasionally cause diarrhoea.

Clinical signs

Affected animals being very ill and have diarrhoea, signs of colic, high temperature, increased heart rate and toxaemia.

Diagnosis

A diagnosis is usually made by the history of recent antibiotic treatment.

Treatment

These animals often require hospitalisation so that they can receive supportive therapy such as fluids to counteract the dehydration, flunixin, an anti-inflammatory drug, to try and prevent or counteract endotoxaemia. Polymixin B is also occasionally used to neutralise endotoxins.

Other causes of diarrhoea in adults

Other causes of diarrhoea include liver disease, peritonitis and congestive heart failure.