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The efficacy of a novel topical liposome‐encapsulated preparation of bleomycin (Bleosome) was studied in 118 clinical cases of equine sarcoid and efficacy was compared with two other standard conventional treatments, tazarotene and 5‐fluorouracil (5‐FU) as well as with the Bleosome in combination with each of these two conventional treatments. Treatments were arbitrarily assigned. Fifty‐two of the 118 sarcoids (44%) were resolved after 12 months but there were significant differences between treatment groups with the combinations of either 5‐FU and bleomycin, or tazarotene and bleomycin resulting in significantly superior resolution of 77 and 78% of the lesions, respectively. The preliminary results suggest that bleomycin in a liposomal carrier may be a useful treatment modality for superficial, diffuse and verrucose sarcoids. The treatment process was simple, and outcomes were functionally and cosmetically excellent. Liposome‐encapsulated bleomycin is economic compared to radiation and other treatment options and can be applied effectively by the owner under guidance. Further studies with different administration protocols and higher concentrations of bleomycin are warranted.

This article discusses the main treatments for sarcoid and the specific difficulties of these. It explains to some extent why the frustrations of a condition for which there is no single treatment option have led to the burgeoning of an industry of irrational treatments. The factors that need to be considered before selecting an option for treatment are wider than is the case in most other disease entities as a result of the complexity of the condition, its variable phenotypes, and the individual perceptions and experiences of both veterinarians and owners.

Research has shown that the accuracy of the clinical diagnosis of equine sarcoids (ES) can be improved. Particularly, less experienced veterinarians are often mistaken in their clinical judgement despite a high level of diagnostic confidence. The aim of this study was to develop and assess the performance of a diagnostic protocol (DP) to improve diagnostic accuracy and identify diagnostically challenging cases. The design of the DP was based on typical clinical features of ES and its algorithm was optimised through repeated tests on clinical cases prior to validating its performance in a representative online examination. A total of 22 equine practitioners and 31 veterinary students used the DP to diagnose 40 standardised ES and non-ES cases in an online examination. Scores of these 53 respondents were compared to scores of 128 respondents of comparable levels of expertise, and 14 experts, all assessing the same cases without using the DP. Overall, respondents using the DP were significantly more likely (odds ratio (OR) 1.25; 95% confidence interval (95% CI) 1.09-1.43) to diagnose a case correctly compared to respondents not using the DP and felt significantly more confident of their diagnosis (OR 1.53; 95% CI 1.39-1.67). Thus, the DP proved to be a reliable tool to increase clinical diagnostic accuracy and diagnostic confidence. The DP algorithms may be further improved with experiences gained from its application in equine practice and clinicians will be able to optimise their diagnostic accuracy and selection of lesions requiring a biopsy.

Derek C Knottenbelt OBE, BVM&S, DVM&S, DipECEIM, DACVIM, MRCVS and Jenny Croft BVMS, MRCVS of Equine Medical Solutions discuss this complicated condition

Skin disease in donkeys is less common than in horses, but is easily overlooked. Little published material exists on this important area of equine medicine. Skin tumors continue to challenge veterinarians working with donkeys. This article outlines the main disease entities that the author has encountered, although there are many other diseases and disorders that occur in different parts of the world that are not yet appreciated. When investigating a skin disease, a logical and comprehensive clinical approach should always be made; many conditions are similar in clinical presentation or are complicated by comorbidity or secondary infection, infestation, or self-trauma.

A 12-year-old Warmblood mare was presented with an acute onset left hindlimb lameness associated with generalised soft tissue swelling of the entire limb and medial saphenous vein (MSV) thrombophlebitis. A presumptive diagnosis of extremity compartment syndrome (ECS) was made. Due to the clinical deterioration, emergency fasciotomy of the crural fascia and biopsy was performed. Histological and immunohistochemical examination of the samples confirmed a diagnosis of leiomyosarcoma likely originating from the tunica media of the MSV. This report is the first to describe an unique combination of ECS and thrombophlebitis associated with a leiomyosarcoma in a horse.

This article discusses the main treatments for sarcoid and the specific difficulties of these. It explains to some extent why the frustrations of a condition for which there is no single treatment option have led to the burgeoning of an industry of irrational treatments. The factors that need to be considered before selecting an option for treatment are wider than is the case in most other disease entities as a result of the complexity of the condition, its variable phenotypes, and the individual perceptions and experiences of both veterinarians and owners.

Few skin diseases specifically or exclusively affect older horses and donkeys. Hypertrichosis (hirsutism) associated with pituitary pars intermedia dysfunction is probably the most recognized and best understood exception and is the most common age-related skin condition in equids. Many other conditions are known to be more serious in older horses. Horses affected with immune-compromising conditions can be more severely affected by infectious diseases of the skin or heavy and pathologically significant parasitism. Neoplasia of the skin is probably more prevalent and worse in older horses, although many of the more serious skin tumors develop initially at a younger age.

Inflammatory bowel disease is a common cause of weight loss in horses and collection of intestinal biopsies is recommended in suspected cases to achieve a definitive diagnosis. Following a biopsy, the client9s expectation is that a definitive diagnosis will clearly define treatment options and prognosis; however, there are very few publications to guide the practitioner in making decisions. This article aims to summarise the implications of different histopathological diagnoses to guide treatment options and assess prognosis.

Summary This report describes the case of a horse presented with cutaneous lesions caused by Blastomyces dermatitidis in the absence of signs of other organ involvement. Diagnosis was achieved through cytology, histopathology and culture. Surgical debulking associated with systemic therapy with oral fluconazole resulted in significant remission; however, recurrence occurred following presumed early cessation of treatment.

Professor Derek Knottenbelt, OBE BVM&S DVM&S DipECEIM MRCVS, discusses the diagnosis and treatment of this frequently underestimated, yet complex condition

Summary Reasons for performing study: Feed supplements are commonly used by owners to alleviate headshaking; however, randomised, controlled trials are required to assess their efficacy. Objective: To determine the efficacy of a feed supplement for alleviation of the clinical signs of headshaking using a randomised, blinded, placebo-controlled trial. Methods: Using a crossover design, 44 horses previously diagnosed with chronic idiopathic headshaking received both the supplement and a matching placebo per os for 28 days with a washout period between of 14 days. Video recordings were taken at rest and exercise prior to the study and at the end of both periods of treatment. The degree of headshaking was assessed in a blinded, randomised manner by 2 veterinary surgeons. At the same time points, owners completed a questionnaire to assess the severity of headshaking signs. A Wilcoxon signed rank test was used to compare the scores while on supplement and placebo. Results: Using the video assessments, there was no significant difference between scores while on supplement compared with placebo (P = 0.7). Using the questionnaire responses, there was no significant difference between scores for any activity when the placebo and the supplement were compared with each other. However, owners reported significant improvement during all activities for both placebo and supplement compared with pretreatment scores. Conclusions and potential relevance: The supplement offered no benefit over a placebo in alleviating the clinical signs of headshaking. There appeared to be a significant proxy placebo effect when the outcome was based on subjective owner perception of clinical signs. This study demonstrated no beneficial effect of this supplement on the clinical signs of headshaking. The study did show a significant placebo effect, thereby highlighting the necessity of properly conducted, randomised controlled trials, with blinding, to assess true treatment effects in trials in animals.

Summary Equine melanocytic tumours may be either a benign or malignant skin disease. They commonly involve the skin of grey horses. There are no reports of mid-tail melanocytoma with sudden malignant transformation. Partial tail amputation was used to resect a melanocytic tumour mass from the mid-tail of a 16-year-old bay Irish Draught (ID) horse. There was no evidence of significant re-growth or complications at a 6-month post operative examination.

A logical and thorough clinical investigation should provide the best basis for the diagnosis of skin diseases. Where no diagnosis can be reached despite a full range of investigations, the clinician can justifiably attempt symptomatic treatment, but it is always better to focus treatment on a specific condition based on properly accumulated and tested clinical evidence. Unfortunately, in equine dermatology there are few text descriptions of the majority of the conditions encountered in practice. While a few diseases are well recognized, there is still little consensus on the best treatments for many of them. Individual veterinarians will have treatments that they rely on, but frequently the same treatment applied by another person inexplicably fails to work in the same way. In dermatology cases, there is no substitute for experience. Referencing to quality textbooks and to colleagues who might have encountered the condition before is often advisable. Unusual presentations are frequently encountered in horses. For example, there are many manifestations of the pemphigus group of diseases, and not all will have a clear diagnostic pathway. It is important to remember that the skin is one of the biggest organs in the body and yet little is known of its function and pathology! While there are many significant primary dermatologic conditions, there are also important systemic diseases that have more or less pathognomonic secondary dermatologic signs; this makes the proper clinical examination even more imperative. One of the biggest problems with equine dermatology is the dearth of scientific reports. Many experienced clinicians have much useful information, but this may never reach the rest of the profession. Also there are few useful reference textbooks dedicated to the equine species. Equine dermatology most likely suffers the most of all disciplines in this respect. As a result, every clinician is expected to reinvent the wheel! There is a need for publications and discussions about the problem cases; even the commonest skin diseases are poorly understood. To make the most use of the supporting specialties of microbiology and pathology, it is important to involve the relevant specialists in the diagnostic process. This means that these specialists must have as much information as they can get; it helps enormously if a photograph can be taken of the disease. Without such information, pathologists and microbiologists may make gratuitous statements about treatment options. For example, a biopsy from an upper eyelid lesion might be easily diagnosed as a sarcoid, and any statement concerning wide surgical excision might be both misleading and nonsensical but would be totally avoidable had the specialist been provided more information. The approach to the dermatologic case requires a logical and exhaustive clinical investigation involving a thorough history and a detailed clinical examination. Diagnostic tests should be carefully selected to rule-out or confirm a suspected diagnosis. Frequent reexaminations are often required because it is sometimes difficult to establish the primary condition: this is often due to extensive self-inflicted trauma or iatrogenic interference by the owner. By proceeding in a systematic and stepwise manner, equine ambulatory clinicians can frequently bring dermatologic problems to a successful resolution.

Summary Reasons for performing study: Idiopathic headshaking is often a facial pain syndrome, but a diagnostic protocol has not been described. In a previous study, caudal compression of the infraorbital nerve for treatment offered a fair success rate, but low case numbers and short follow-up time were limitations. Objectives: To describe a diagnostic protocol for headshaking, examining the role of bilateral local analgesia of the posterior ethmoidal nerve (PET block). To report longer-term follow-up after surgery of the original cases and further cases and to determine whether changes to the technique influence success rates and complications. Methods: Records of horses that had undergone PET block and caudal compression surgery at 3 hospitals were reviewed. Modifications to the surgical technique included placing additional coils into the infraorbital canal and/or performing concurrent laser cautery of the nerve. Follow-up information was obtained by telephone contact with owners. Results: The PET block was performed in 27 horses, with a positive result in 23 of 27 (85%). Surgery was performed in 58 horses. A successful outcome was initially achieved in 35 of 57 (63%) horses, but recurrence occurred between 9 and 30 months later in 9 (26%). Surgery was repeated in 10 of 31 (32%) horses. Final success rate, considering only response to the last performed surgery, was 28 of 57 (49%) horses with median follow-up time of 18 months (range 2–66 months). Nose-rubbing was reported post operatively in 30 of 48 (63%) horses. This resolved in all but 4 horses, which were subjected to euthanasia. Response to PET block or change in surgical technique did not appear to influence outcome or complications. Conclusions and potential relevance: The diagnostic protocol described is recommended for the investigation of headshakers. Caudal compression offers the best prognosis for a successful outcome compared with other treatments, for horses in which the only alternative is euthanasia. Surgical treatment of the disorder requires refinement, and the pathogenesis of the disorder requires investigation.

In the first of a new series, Professor Derek Knottenbelt, of Equine Medical Solutions Ltd explains why it is so imperative that sarcoids are treated as early as possible

M ost tumour conditions of the horse affect the skin and are a relatively common occurrence. The management of cutaneous neoplastic diseases has improved but, in spite of significant progress in other species, the horse still lags behind. Currently the major emphasis in cutaneous oncology is focused on: z z Equinezsarcoid:zEncompasses a spectrum of fibroblastic tumours that include neurofibroma, spindle cell sarcoma, fibrosarcoma and myxofibrosarcoma z Equinezmelanoma: Includes recognised variations, some of which are highly malignant, but in the majority are singularly benign z Squamouszcellzcarcinoma:zThe most aggressive SCC is that in the stomach but there are highly dangerous variants of the cutaneous form that occur in the prepucial and vulvar regions zMastzcellztumour: Mostly reported around the face and eye regions and on the distal limbs. Little is known about these and more reports of the pathology and clinical behaviour are required. They are usually solitary and can be localised and well encapsulated or malignant invasive. There are few reports of metastatic spread. They are generally considered to be good surgical candidates. These tumours make up over 95% of cutaneous tumours in the horse. The remainder are lymphoma and various forms of lymphosarcoma, basal cell carcinoma, haemangiosarcoma and mastocytoma. Additionally, there are many individual reports of unusual tumours such as keratacanthoma, sebaceous adenoma and others. Very young foals may also have cutaneous haemangioma; these are both difficult to treat and highly dangerous if left. The most difficult cutaneous tumours to treat are those that are cutaneous manifestations of internal or widely disseminated tumours such as lymphosarcoma.

Horse wounds have a high risk of becoming infected due to their environment. Infected wounds harbour diverse populations of microorganisms, however in some cases these microorganisms can be difficult to identify and fail to respond to antibiotic treatment, resulting in chronic non-healing wounds. In human wounds this has been attributed to the ability of bacteria to survive in a biofilm phenotypic state. Biofilms are known to delay wound healing, principally due to their recalcitrance towards antimicrobial therapies and components of the innate immune response. This study describes the presence of bacterial biofilms within equine wounds. Thirteen 8-mm diameter tissue samples were collected from (n = 18) chronic wounds. Following histological staining, samples were observed for evidence of biofilms. Fifty one wounds and control skin sites were sampled using sterile swabs. Control skin sites were on the uninjured side of the horse at the same anatomical location as the wound. The isolated bacteria were cultured aerobically and anaerobically. The biofilm forming potential of all the isolated bacteria was determined using a standard crystal violet microtitre plate assay. Stained tissue samples provided evidence of biofilms within 61.5% (8 out of 13) equine wounds. In total 340 bacterial isolates were identified from all the equine wound and skin samples. Pseudomonas aeruginosa and Enterococcus faecium were the most predominantly isolated bacterial species from equine wound and skin samples respectively. Staphylococcus was the most commonly isolated genus in both environments. Bacteria cultured from chronic and acute wounds showed significantly (P < 0.05) higher biofilm forming potential than bacteria isolated from skin. This paper highlights preliminary evidence supporting the presence of biofilms and a high microbial diversity in equine chronic wounds. The presence of biofilms in equine wounds partly explains the reluctance of many lower limb wounds to heal. Non-healing limb wounds in horses are a well documented welfare and economic concern. This knowledge can be used to shape future treatments in order to increase the healing rate and decrease the costs and suffering associate with equine wounds.

Ocular lesions in horses, confirmed as squamous cell carcinoma, were treated topically with mitomycin C. Fourteen horses with confirmed ocular squamous cell carcinoma, three of which were affected bilaterally, were included in the study. Eight of the affected eyes were treated topically with mitomycin C alone; in the other nine eyes, the tumours were surgically removed and topical treatment with mitomycin C was then applied. The treatment protocol consisted of 0.2 ml of 0.04 per cent mitomycin C instilled into the conjunctival sac of the affected eye, every six hours, in rounds of seven days of treatment followed by seven days without treatment. This was repeated until full regression of the tumour occurred (up to four rounds of treatment with mitomycin C). Of the eight eyes treated with mitomycin C alone (without surgery), clinical resolution occurred in six cases. Of the nine eyes treated with a combination of surgery and topical mitomycin C, clinical resolution occurred in seven cases. No complications were observed.

This report summarises clinical and pathological observations on Fell pony foals with a range of signs that included ill thrift, anaemia, respiratory infection, glossal hyperkeratosis and diarrhoea. Some of the foals had normochromic, normocytic anaemia and some had low levels of plasma proteins, including immunoglobulin G. Antibiotic and supportive treatment was ineffective and all affected foals died or were killed on humane grounds. Postmortem examination of 12 foals and tissues from 2 other foals revealed a range of lesions that included glossal hyperkeratosis, typhlocolitis, intestinal cryptosporidiosis, granulomatous enteritis, proliferative and necrotising bronchiolitis consistent with adenovirus infection; lesions similar to those in the respiratory tract were present in the salivary gland and pancreas of individual foals. Lymphoid tissue was judged to be smaller than expected. These observations suggest the possibility of opportunistic infections secondary to some form of undefined immunocompromised state.

REASONS FOR DESIGNING AND REPORTING TECHNIQUE: Idiopathic headshaking has remarkable similarities to human neuropathic facial pain syndromes associated with post herpetic and trigeminal neuralgia. These derive from abnormal sensory function within the peripheral or central pathways of the trigeminal nerve (TgN). Limiting input from the TgN can be helpful in controlling the perception of pain. Rhizotomy of the infraorbital branch of the TgN as it emerges from the infraorbital canal has been reported but has a poor efficacy. A novel technique involves compression of the nerve at a more caudal location within the infraorbital canal and the technique requires validation.Caudal compression of the infraorbital nerve with platinum coils, performed in horses diagnosed with idiopathic headshaking, results in a decrease in clinical signs.Caudal compression of the infraorbital nerve, using platinum embolisation coils, was performed under fluoroscopic guidance. Clinical records of 24 idiopathic headshakers that had undergone this procedure were reviewed. Follow-up information was obtained by telephone questionnaire with the owner or referring veterinary surgeon.All 24 horses had at least one surgical procedure. Median follow-up time was 6 months. There were 2 horses which had surgery 2 weeks before follow-up and these were excluded from the analysis of outcome. Following one surgery, 13/22 horses (59.0%) had a successful outcome. Of the 9 horses that did not improve, surgery was repeated in 6 cases. Two of these horses had a successful outcome. Overall, a successful outcome was obtained in 16/19 horses (84.2%).This surgical technique is likely to prevent input from the TgN at a more caudal location then the previously described infraorbital neurectomy. The technique requires refinement.

Laryngeal paralysis in horses has been reported after inhalational anesthesia and can result in significant morbidity/mortality. The cause of the condition is unclear. The objective of this study was to examine the effects of a standardized anesthetic protocol on laryngeal function and laryngeal/pharyngeal trauma in the peri-anesthetic period in a prospective study. A 30- to 60-second digitalized video clip of laryngeal movement from a standardized endoscopic view was recorded at five time points: before sedation, post-sedation, post-induction, immediately after recovery to standing, and at 24 hours after recovery. A standardized anesthetic regimen was used in all cases. Video clips were randomized and evaluated by two blinded assessors. Each assessor scored each clip for laryngeal function and trauma using previously validated scoring systems. Agreement between assessors was calculated using the mean of the five time-specific weighted kappa statistics. Post-anesthesia laryngeal function and trauma scores were compared with initial scores using the Wilcoxon signed rank test with Bonferroni adjustment. Spearman's rank coefficient was used to assess correlation between trauma and function scores and between anesthetic duration and laryngeal function and trauma scores. There was no significant effect of anesthesia on laryngeal function. Trauma scores were not significantly higher after tracheal intubation. The trauma scoring system requires further validation. There was no correlation between higher trauma scores and laryngeal function or duration and laryngeal function or trauma. Further work is required to evaluate other variables that may affect laryngeal function after anesthesia, using a larger number of horses with varying degrees of laryngeal dysfunction.

Bacteria are renowned for their ability to tolerate and adapt to a wide range of adverse environmental conditions. The primary mechanism that facilitates these adaptations is thought to be the capacity to form and maintain biofilms. Within a biofilm, bacteria become attached to a surface where they exist in complex communities which are able to interact with each other through intracellular communication and thus rapidly adapt to changing environments. The organisms within biofilms are notorious for their resistance towards the host immune response and antibacterial agents compared to their free-living planktonic counterparts. Consequently, biofilms are of significant importance to both clinical and veterinary science. However, although bacterial infections are widely reported in animals their association with biofilms is rarely discussed. The aim of this review is to look at the characteristics of biofilm infections in humans and to relate this knowledge to veterinary science in order to assess their relevance in this area.

Wound research is an evolving science in the equine species. In particular, interest is growing regarding the role that microorganisms play in delaying both acute and chronic wound healing. Equine wounds, particularly lower limb wounds, frequently display delayed healing and infection is commonly the underlying reason. This review will summarize the current research and knowledge surrounding equine wound healing and wound care. Particular focus is placed on the role that microbes play in chronic equine wounds and the significance of associated bacterial biofilms. .