Injuries and outcome of three horses hospitalised in the aftermath of Hurricane Isaac

This case series describes 3 horses rescued from flooded areas, hospitalised and treated at the Louisiana State University Veterinary Teaching Hospital in the wake of Hurricane Isaac. The purpose of the paper is to familiarise practitioners with the injuries that may be found in flood‐afflicted horses and livestock. Case 1 presented with a degloving injury of the right hindlimb. The gelding developed neurological signs and was subjected to euthanasia; necropsy was consistent with Salmonella sepsis and disseminated mycosis due to Candida krusei, the first case reported in a horse. Case 2 presented with dermatitis attributable to chemical exposure and pneumonia and was subjected to euthanasia due to severe bilateral laminitis. Case 3 sustained a degloving injury of the left hindlimb and was subjected to euthanasia due to intractable pain. This case series illustrates the need for preparation and evacuation to avoid life‐threatening injuries in equids and livestock caused by hurricanes and their aftermath.     

A Photometric Method for Recording Hoof Diseases in Cattle,with Special Reference to Haemorrhages of the Sole

Bergsten, C: A photometric method for recording hoof diseases in cattle, with special reference to haemorrhages of the sole. Acta vet. scand. 1993,34,281-286.– After cleaning and trimming, the sole surface and interdigital space of the hooves of cows are photographed in a standardized way. The colour slides are projected on to a screen and the haemorrhages of the sole (reflecting Pododermatitis aseptica diffusa) and the lesions of Dermatitis interdigitalis and Erosio ungulae are scored according to their severity and extent by 2 people who do not know the identity of the cows. In a repeatability test the correlation coefficients between 2 assessments of the haemorrhages in the sole ranged between 0.78 and 0.88 for assessments of the front hooves, the hind hooves and all the hooves together.     

RADIOGRAPHIC APPEARANCE OF THE FEET OF MAMMOTH DONKEYS AND THE FINDING OF SUBCLINICAL LAMINITIS

All feet of 10 clinically sound mammoth donkeys (Group I) were radiographed to determine the appearance of the distal phalanx. The distal phalanges had blunted to concave-shaped dorsal solar margins which varied in appearance from slight to pronounced. The distal phalanges of the forefeet were wider than those of the hindfeet, and also were positioned a greater distance from the dorsal aspect of the hoof wall. The greater distance between the dorsal aspect of the hoof wall and the distal phalanges seemed related to the presence of a periosteal-like bony proliferation on the dorsum of the distal phalanx. This bony proliferation occurred in those distal phalanges which also had radiographic findings consistent with pedal osteitis. Next, all feet of 5 additional mammoth donkeys (Group II) that were to be necropsied for various reasons, were examined similarly to Group I, necropsied and found to have laminitis. Only 2 of these 5 donkeys had been lame; only one had rotation of the distal phalanges (in the forefeet). Radiographic data from the 4 donkeys without rotation seemed most similar to that found in those Group I donkeys which had periosteal reactions on their distal phalanges. Conclusions from this study were that: 1) feet of mammoth donkeys have some anatomic differences from those of domestic horses, 2) subclinical laminitis and pedal osteitis can occur in mammoth donkeys, 3) rotation of the distal phalanx occurs in some, but not all laminitic donkeys, 4) laminitic changes may be more pronounced in their fore than in their hindfeet, and 5) additional studies of donkeys need to be done, examining both proven normal and confirmed laminitic feet.     

Effects of endotoxaemia and carbohydrate overload on glucose and insulin dynamics and the development of laminitis in horses

Reasons for performing study: Insulin resistance (IR) is a risk factor for pasture‐associated laminitis in equids and alimentary carbohydrate overload may trigger laminitis. Whether glucose metabolism responses to carbohydrate overload are more pronounced in insulin‐resistant horses requires further study. Hypothesis: Horses pretreated with endotoxin to alter insulin sensitivity differ significantly in their glucose and insulin responses to carbohydrate overload. Methods: Horses (n = 24) were divided into 3 groups. A lipopolysaccharide (LPS; n = 8) group that received endotoxin as an 8 h 7.5 ng/kg bwt/h i.v. continuous rate infusion, an oligofructose (OF; n = 8) group that received an infusion of saline followed by 5 g/kg bwt OF via nasogastric intubation, and a LPS/OF (n = 8) group that received LPS followed 16 h later by OF. Glucose and insulin dynamics were evaluated at ‐24 h and 48 h using the frequently sampled i.v. glucose tolerance test and minimal model analysis. Physical examinations and haematology were performed and the severity of laminitis assessed. Results: Horses receiving LPS developed leucopenia and both LPS and OF induced clinical signs consistent with systemic inflammation. Insulin sensitivity significantly decreased (P<0.001) over time, but responses did not differ significantly among groups. Time (P<0.001) and treatment × time (P = 0.038) effects were detected for the acute insulin response to glucose, with mean values significantly increasing in LPS and LPS/OF groups, but not the OF group. Five horses in the LPS/OF group developed clinical laminitis compared with 0 and 2 horses in the LPS and OF groups, respectively. Conclusions: Endotoxaemia and carbohydrate overload reduce insulin sensitivity in horses. Endotoxin pretreatment does not affect the alterations in glucose metabolism induced by carbohydrate overload. Potential relevance: Insulin sensitivity decreases after carbohydrate overload in horses, which may be relevant to the development of pasture‐associated laminitis.     

Expression and Activity of Collagenases in the Digital Laminae of Horses with Carbohydrate Overload‐Induced Acute Laminitis

Background

Matrix metalloproteinases (MMP) are hypothesized to degrade structurally important components of the laminar extracellular matrix (ECM) in horses with laminitis.

Objective

To compare levels of expression of stromelysin‐1 (MMP‐3), collagenases (MMP‐1, ‐13), and membrane type‐MMPs (MMP‐14, ‐15, ‐16), and the distribution of their ECM substrates, in laminae of healthy horses and horses with carbohydrate overload laminitis.

Animals

Twenty‐five adult horses.

Methods

Gene and protein expression were determined in extracts of laminae using real‐time quantitative polymerase chain reaction and Western blotting after sodium dodecylsulfate polyacrylamide gel electrophoresis. Distribution of MMP‐13 and ECM components was determined using indirect immunofluorescent microscopy of nonfixed frozen sections. ECM morphology was assessed by hematoxylin and eosin staining.

Results

Of the genes studied, only those encoding MMP‐1 and ‐13 were upregulated in CHO‐induced laminitis; MMP‐1 at Obel grade (OG)1 lameness and MMP‐13 at OG3 lameness. Laminar MMP‐1 was present as 52 kDa proenzyme only. MMP‐13 was present as pro‐ (61 kDa) and processed (48 kDa) enzyme. MMP‐13 localized to the basal epithelium of the secondary epidermal laminae and its increased expression were accompanied by the appearance in secondary dermal laminae (SDL) of multiple foci that were devoid of collagen I, fibronectin, chondroitin and keratan sulfate glycosaminoglycans, and eosin‐staining material.

Conclusions and Clinical Relevance

MMP‐13 is upregulated in laminae of horses with CHO‐induced OG3 lameness and, by degrading components of the ECM, may contribute to the formation of ECM‐free lesions (gaps or tears) that appear in the SDL with OG3 lameness.     

An investigation of the possible effects of subclinical iodine deficiency on ewe fertility and perinatal lamb mortality

A controlled supplementation trial was performed in an assumed iodine-deficient Romney ewe flock in the Manawatu. Significantly more twin litters were born to iodine-supplemented ewes than to control ewes. Furthermore, the perinatal mortality rate in lambs born to iodine-supplemented dams was significantly lower than in lambs born to control dams. Ewe age and the use of different lambing paddocks for iodine-supplemented and control ewes may have been confounding factors. In both iodine-supplemented and control ewes, serum T₃ and T₄ concentration values remained above the currently used “normal” range throughout the trial period.