Descriptive epidemiology of joint injuries in Thoroughbred racehorses in training

Reasons for performing study: No large scale epidemiological studies have previously quantified the occurrence of carpal, metacarpo‐ and metatarsophalangeal (MCP/MTP) joint injuries in Thoroughbred racehorses. Objectives: To develop an objective classification system for carpal and MCP/MTP joint injuries and estimate the incidence of these injuries in young Thoroughbreds in flat race training. Methods: In a prospective cohort study, data on daily exercise and veterinary‐diagnosed carpal and MCP/MTP joint injuries were collected from Thoroughbreds monitored since starting training as yearlings, for up to 2 years. Cases were classified in one of 4 categories: 1) localised to a carpal or MCP/MTP joint based on clinical examination and/or diagnostic analgesia; no diagnostic imaging performed; 2) localised to a carpal or MCP/MTP joint based on clinical examination and/or diagnostic analgesia; radiographs taken but no abnormalities detected; 3) evidence of abnormality of subchondral bone and/or articular margin(s) on diagnostic imaging and 4) evidence of discontinuity of the articular surface on diagnostic imaging. Incidence rates and rate ratios were estimated using Poisson regression, adjusting for trainer‐level clustering. Results: A total of 647 horses from 13 trainers throughout England contributed 7785 months at risk of joint injury. One‐hundred‐and‐eighty‐four cases of carpal (n = 82) or MCP/MTP (n = 102) joint injury were reported in 165 horses and classified in Category 1 (n = 21), Category 2 (n = 21), Category 3 (n = 72) or Category 4 (n = 70). The overall joint injury rate was 1.8 per 100 horse months (95% CI = 1.2, 2.8); rates did not differ significantly between 2‐ and 3‐year‐olds but females sustained Category 1 injuries at triple the rate of males (P = 0.03). Joint injury rates differed significantly between trainers (P<0.001) and there was trainer variation in anatomical site and severity of injury. Conclusions and potential relevance: Carpal and MCP/MTP joint injuries are an important cause of morbidity in Thoroughbred racehorses. Identification of modifiable risk factors for these injuries may reduce their incidence.     

Studies on the phloroglucinol–HCl reactive material produced by squash fruit elicited with pectinase: Isolation using hydrolytic enzymes and release of p -coumaryl aldehyde by water reflux

Pathological tissues from a variety of plants turn red when treated with the histochemical reagent phloroglucinol (PG)–HCl. This induced PG–HCl reacting material has been termed both wound gum and, more recently, induced lignin or lignin-like material. We are exploring alternative approaches to better identify this induced material. In this report, we describe methods for purifying the PG–HCl reactive material from solvent-washed tissue preparations and measuring the amount of p -coumaryl aldehyde released from the purified material by boiling in water. Acorn squash fruit wall tissue was sliced, sprayed with pectinase to elicit the formation of PG–HCl reactive material and incubated up to 72 h at 27°C. Sampled tissue was washed extensively with water and organic solvents. Insoluble residues were treated with cell wall degrading enzymes to remove cell wall materials, and dimethyl sulfoxide was used to dissolve starch. Yields of residual material increased from 7.5% in the time zero samples to 29.7% after 72 h. Refluxing the purified material in water released <6 μ g p -coumaryl aldehyde g⁻¹ from preparations of tissue at time zero and 8100 μ g p -coumaryl aldehyde g⁻¹ from samples incubated for 48 h. These results suggest that the function of the material is to sequester phytoalexins, but are not consistent with the material being lignin. Published by Elsevier Science Ltd.     

Ectopic cilium in seven horses

Ectopic cilium was diagnosed by slit-lamp biomicroscopy and treated surgically by transconjunctival excision in seven adult horses. All cases presented with a common history of blepharospasm, ocular discharge and keratitis. Ophthalmic examination revealed a single translucent cilium in the upper eyelid palpebral conjunctiva, emerging approximately 5 mm from the eyelid margin. Corneal ulceration was not observed in any horse. Most horses responded well to transconjunctival surgical excision. There was recurrence of ectopic cilium 6 weeks postoperatively in one horse. Histopathologic examination was performed in two cases and confirmed the diagnosis of ectopic cilium in one horse. This is the first publication of ectopic cilia in horses and emphasizes their importance as etiology for epiphora, blepharospasm and keratitis.     

Successful surgical management of a medial humeral epicondyle fracture in a Thoroughbred foal

A 2-week-old 75 kg Thoroughbred filly was presented for the investigation of an acute forelimb lameness. Radiographs revealed a fracture of the medial epicondylar physis of the left humerus (Salter–Harris type II fracture). The fragment was removed via arthrotomy under general anaesthesia. Two months post-operatively, the foal was sound and at 2 years had resumed normal turn out. This case report describes a previously unreported surgical treatment for a fracture of the medial epicondylar physis in a foal.     

Genotype environment interactions and sib content in F1 hybrid —brussels sprouts

Summary Sib content of F₁ hybrid seed lots obtained from crossing four highly self incompatible brussels sprout lines was examined at two locations for four years. Parental combinations accounted for by far the greatest proportion of the total variation observed. Significant second and third order interactions terms suggest complex interactions between parental genotype, years, and locations. Attempts to interpret these data in terms of the regression model of Finlay & Wilkenson (1963), were unsuccessful.     

Growth of graded sweetgum 3 years after root and shoot pruning

Nursery grown 1–0 bareroot sweetgum seedlings were lifted and graded into two diameter classes (12–16 and 4–8 mm) during the dormant season. Large and small grades were top and/or root pruned and then outplanted on two sites in the lower Coastal Plain of the southeastern United States. Seedling shoots were pruned to 50% of tree height, a 5 cm stump, or no pruning. Seedling roots were pruned to a 15 cm length or left unpruned. Site affected survival but not growth. Smaller, top pruned seedlings performed worse on one site, probably due to greater weed competition. Large seedlings increased survival and growth which increased 3 year average plot volumes by 89%. Top pruning stimulated height growth, but reduced diameter growth and decreased third year seedling volumes. Root pruning did not affect seedling growth. Diameter growth may better indicate treatment impact that height, which has been most commonly used in previous studies.     

Concurrent or sequential development of medial meniscal and subchondral cystic lesions within the medial femorotibial joint in horses (1996–2006)

Reasons for performing study: Medial meniscal injuries and subchondral cystic lesions (SCL) are known to occur independently within the medial femorotibial (MFT) joint in horses. However, there are no reports of a potential clinical relationship between these 2 types of lesions. Objectives: To: 1) document the concurrent presence or sequential development of medial meniscal and SCL of the medial femoral condyle within the MFT joint; and 2) determine the prognosis with both types of lesions. Methods: Retrospective case series of horses with both a medial meniscal and SCL of the medial femoral condyle identified concurrently or sequentially by radiography, arthroscopy or post mortem examination. Case records and radiographs were reviewed, and a telephone survey of referring veterinarians, owners and trainers was conducted. Results: Twenty‐one horses (9.1% of all horses undergoing MFT joint arthroscopy) were identified to have both a medial meniscal injury and SCL of the medial femoral condyle. Thirteen horses had both abnormalities identified concurrently, 6 developed a meniscal lesion subsequent to SCL debridement, and 2 developed a SCL subsequent to a medial meniscal injury. Only 4/19 horses were classified as successful and returned to their intended use. The severity of the meniscal injury was significantly associated with the severity of lameness but not with outcome. Conclusions: A low percentage of horses may develop both a meniscal injury and SCL of the medial femoral condyle within the MFT joint and have a poor prognosis. Potential relevance: Trauma to the MFT joint may lead to both meniscal and subchondral bone damage of the medial femoral condyle that may be recognised concurrently or sequentially.