Colitis X in the horse

Abstract

Extract

Colitis X is a peracute, sporadic noncontagious disease affecting horses of all ages, characterized by sudden onset of shock, dehydration and foetid diarrhoea (Rooney et al., 1963 Rooney, J. R., Bryan's, J. T. and Doll, E. R. 1963. Colitis “X” of horses. J. Am. vet. Med. Ass., 142: 510–511.  [Google Scholar]; Pickrell, 1968 Pickrell, J. W. 1968. Equine killer: Colitis X. Med. vet. Pract., 49: 63–66.  [Google Scholar]). Rooney et al. (1966 Rooney, J. R., Bryans, J. T., Prickett, M. E. and Zent, W. W. 1966. Exhaustion shock in the horse. Cornell Vet., 56: 220–235. [PubMed] , [Google Scholar]) have described a form of colitis X without diarrhoea. Otubreaks of the disease which affected numerous horses under the same conditions of management have been described (Rooney et al., 1963 Rooney, J. R., Bryan's, J. T. and Doll, E. R. 1963. Colitis “X” of horses. J. Am. vet. Med. Ass., 142: 510–511.  [Google Scholar]; W. P. C. Richards, pers. comm.).     

Equine Colitis “X”, Still an Enigma?

Colitis “X” is a sporadic diarrheal disease of horses with clinical signs of dehydration, electrolyte imbalances and “shock”-like features. Macroscopic and microscopic findings include signs of disseminated intravascular coagulation, necrosis of colonic mucosa and presence of large numbers of bacteria in the devitalized parts of the intestine. Recently published work suggests that the causative agent may be Clostridium perfringens, Type A, but the bacteria are recoverable only in the preliminary stages of the disease. Excess protein and lack of cellulose content in the diet is thought to be the trigger for the multiplication of the clostridial organisms. The pathological findings are pathognomonic, but clinically, a number of differential diagnoses have to be considered, such as intestinal accidents, salmonellosis, heavy metal intoxication and occlusive verminous arteritis.     

The epidemiology of the "collapse syndrome" in suckled calves.

Cases of a diarrhoeic syndrome characterised by acute collapse were seen in single-suckled beef calves on hill farms during a three year period. The association between the occurrence of this syndrome, which we have termed the "collapse syndrome", and various epidemiological parameters, is investigated and discussed.     

The association of erythromycin ethylsuccinate with acute colitis in horses in Sweden

In Sweden there are several reports of mares developing acute colitis while their foals were being treated orally for Rhodococcus equi pneumonia with the combination of erythromycin and rifampicin. In this study 6 adult horses were given low oral dosages of these antibiotics, singly or in combination. Within 3 days post administration of erythromycin, in one case in combination with rifampicin, 2 horses developed severe colitis (one fatal). Clostridium difficile was isolated from one of the horses, whereas no specific pathogens were isolated from the other. Both horses had typical changes in blood parameters seen in acute colitis. Clostridium difficile was also isolated from the faeces of a third horse given an even lower dosage of erythromycin in combination with rifampicin. This horse developed very mild clinical symptoms and recovered spontaneously. In the fourth horse given erythromycin only, very high numbers of Clostridium perfringens were isolated. The horses given rifampicin only did not develop any clinical symptoms and there were no major changes in their faecal flora. In conclusion, it has been demonstrated that low dosages of erythromycin ethylsuccinate can induce severe colitis in horses associated with major changes of the intestinal microflora. Clostridium difficile has been demonstrated as a potential aetiological agent in antibiotic-induced acute colitis.     

Myeloperoxidase activity of the large intestine in an equine model of acute colitis.

OBJECTIVE: To determine whether quantification of myeloperoxidase (MPO) activity could be a useful laboratory technique to detect granulocyte infiltration in equine intestinal tissues. SAMPLE POPULATION: Intestinal tissue (inflamed or healthy) collected from 16 age- and sex-matched Shetland Ponies. PROCEDURE: Intestinal tissue MPO activity was determined, and histologic assessment of adjacent specimens from healthy and inflamed intestine was done. RESULTS: Intestinal tissue MPO activity and histopathologic score increased with time after castor oil challenge and peaked at 16 hours in an equine diarrhea model in which individual ponies provided their own control tissues. CONCLUSIONS: Intestinal tissue inflammation scores correlated positively with tissue MPO activity in adjacent specimens. CLINICAL RELEVANCE: Tissue MPO assay may be a useful laboratory tool to quantify intestinal mucosal inflammation in ponies.     

Biochemical studies of the "collapse syndrome" in suckled calves.

A total of 351 single-suckled beef calves were blood sampled at twice-weekly intervals for the first two and a half weeks of life. Twenty three of them died, 13 of a syndrome characterised by acute collapse and 10 of diarrhoea which had persisted for several days before death. Those which died acutely showed a sudden terminal rise in blood levels of potassium, magnesium, inorganic phosphate and total protein. Those which died after several days of diarrhoea showed a more gradual increase in blood chloride and urea concentrations and in packed cell volume values. It is suggested that these changes indicate a difference in the pathogenesis of the two situations. Calves which died had lower blood glucose levels before the onset of clinical signs than those which survived. It is suggested that this may have been a contributory factor in their mortality.     

Immune globulin studies of the "collapse syndrome" in suckled calves.

A total of 351 single suckled beef calves were blood sampled during the first three days of life and thereafter twice weekly until five samples had been obtained. Eighty four calves suffered from diarrhoea and 23 of these died. No relationship could be found between the total circulating immune globulin level of a calf and its subsequent fate, suggesting that the syndrome with which many calves were affected is different in character from other forms of neonatal bovine diarrhoea.     

The equine metabolic syndrome peripheral Cushing's syndrome.

Certain management practices tend to promote the development of obesity (metabolic syndrome) in mature horses as they enter their teenage years. These management practices include the provision of starch-rich (high glycemic index) and fat-supplemented rations to healthy horses that are relatively inactive. Some horse breeds and ponies appear to be genetically predisposed to metabolic syndrome. The accretion of intra-abdominal adiposity by equids is associated with the development of insulin insensitivity (hyperinsulinemia), glucose intolerance, dyslipidemia, hypertension, and insidious-onset laminitis. Omental adipocytes are metabolically active, secreting free fatty acids and hormonally active mediators including cortisol, leptin, and resistin that might contribute to persistence and worsening of insulin refractoriness and the obese phenotype. We have hypothesized that obesity-associated laminitis arises as a consequence of vascular changes and a hypercoagulable state, similar to the development of atherosclerosis in human type 2 diabetes. Several molecular mechanisms that might serve to explain the development of insulin insensitivity as a result of excessive adiposity have been incriminated. Little investigation into the relationship between obesity, insulin insensitivity, and laminitis in horses has been reported to date. Insulin sensitivity and glucose tolerance can be improved by dietary restriction and exercise aimed at reversing omental obesity. Management practices that promote the development of obesity are likely initiated during the first 10 years of the horse's life. Veterinarians and horse owners must recognize that mature-onset obesity in adult horses is associated with a risk for development of laminitis. Obesity and insulin insensitivity might be prevented if horse owners can be educated to feed rations with a relatively lower glycemic index to inactive horses. Investigative research pertaining to the development of antiobesity drugs for human patients is continuing. Greater than 30 new pharmaceuticals are in various stages of research. However, it will likely take many years before any of these drugs are shown to be useful and safe in horses. Lifestyle changes in the form of diet and exercise patterns are still the crux of therapy for both human and equine patients.     

The "barker" (neonatal respiratory distress) syndrome in the pig: its occurrence in the field.

A new syndrome, characterised by acute respiratory distress and by abnormalities of the skin, hair and thyroid, was the apparent cause of neonatal death in 35 (24 per cent) of 146 piglets sired by a large white boar in four small commercial pig units. The syndrome appears to be of genetic origin, inherited as an autosomal recessive trait. Its similarities with the respiratory distress syndrome (RDS) of the newborn infant and the "barker" syndrome of the newborn foal are discussed.     

Inheritance of the "rat-tail" syndrome and its effect on calf performance.

A form of congenital hypotrichosis, commonly know as the "rat-tail syndrome," occurs in a small percentage of calves produced by crossing some Continental cattle breeds with cattle that are black in color. These calves are characterized by short, curly, malformed, sometimes sparse hair and a lack of normal tail switch development. In our first study, performance of 43 rat-tail calves was compared with that of 570 non-rat-tail calves of the same breeding and contemporary groups. All rat-tail calves were sired by Simmental bulls and were from cows with various percentages of Angus breeding. The rat-tail condition had no effect on birth weight, weaning weight, or gain from birth to weaning. However, rat-tail calves had significantly lower rates of gain during the winter months from weaning to yearling than non-rat-tail calves, resulting in a 19 kg lighter yearling weight. Gains of steers from yearling to slaughter were not significantly different, but rat-tail steers were 36 kg lighter (P = .01) and 13 d older (P = .15) at slaughter than the non-rat-tail steers. In a second study, Angus-Simmental F1 males and females with the rat-tail condition were mated to produce 64 F2 offspring that were used to determine the mode of inheritance of this syndrome. Analysis showed that the rat-tail syndrome is controlled by interacting genes at two loci. Cattle that express the syndrome must have at least one dominant gene for black color and be heterozygous at the other locus involved.