A case of spontaneous autoimmune skin disease in a cynomolgus monkey (Macaca fascicularis)

Pemphigus is an autoimmune blistering disease characterized by lesions on the skin and mucous membranes. To date, no spontaneous cases of this disease have been reported in cynomolgus monkeys. This report describes the histopathological characteristics of spontaneous pemphigus in a cynomolgus monkey. Macroscopically, redness and scaling with pruritus were observed on the skin of the entire body. Histopathologically, the epidermis showed intercellular edema, and eosinophils and mononuclear cells infiltrated the epidermis. There was no obvious acantholysis in the epidermis. The perivascular area showed edema, and eosinophils and mononuclear cells infiltrated the vessels in the dermis. Immunohistochemically, the intercellular area in the epidermis was positive for Immunoglobulin G and Complement component 3. Serologically, anti-desmoglein 1 and desmoglein 3 antibodies in the serum were negative. From these findings, this case was diagnosed as an autoimmune skin disease, suspected to be pemphigus, and concluded as lesions being similar to those in human “pemphigus herpetiformis”.     

Use of random pattern skin flaps for wound closure in two horses

A 9-year-old Thoroughbred broodmare presented with a mass rostral to the medial canthus of the left eye. The mass was removed under general anaesthesia and the wound bed infiltrated with carboplatin emulsion before partially closing using a Z-plasty. The mass recurred and subsequently was resected twice. It has not recurred 68 weeks post-treatment. The second case describes removal of a granulomatous mass from the metatarsus of a yearling Thoroughbred colt. Skin expanders and a rotational flap were used to allow tension-free closure. This required two separate surgeries to firstly insert the skin expanders and secondly to remove the mass, the expanders and to close the defect. The wound healed with good cosmesis. There have been few reports on the use of skin flaps in equine reconstructive surgery in the last 30 years. This report details two cases of wound closure where skin flaps were used to achieve primary intention wound healing.     

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.     

Autologous conditioned plasma as therapy of tendon and ligament lesions in seven horses

This case report describes the intralesional application of autologous conditioned plasma (ACP) in seven horses as treatment of severe tendinitis of the superficial digital flexor tendon, deep digital flexor tendon, or desmitis of the inferior check ligament. Follow-up data of the horses revealed a positive outcome in 10 to 13 months post injury. All horses treated with ACP were either performing in their previous work-load or were back in full training. Further studies with long-term follow-up will have to be performed to support these clinical intermediate-term observations.     

Results of intradermal testing for the investigation of atopic dermatitis and recurrent urticaria in 50 horses in the south of England

Atopic dermatitis (AD) and recurrent urticaria (RU) are common immune‐mediated conditions of horses and ponies associated with high morbidity. Effective pharmacological treatment options are limited but identification of the causal allergens allows avoidance strategies and immunotherapy regimens to be employed. Intradermal testing (IDT) is the most widely accepted means of identifying the relevant allergens but there are no published reports of this technique being used in the UK for the investigation of dermatological disease. This study presents the results of testing with a varied panel of allergens in 50 horses with dermatological disease living in the south of England. Intradermal testing was performed in horses presented to The Liphook Equine Hospital for further investigation of AD or RU between June 2002 and March 2009. Allergen selection was based upon availability, results of previous studies, pollen charts and the likelihood of allergens being prevalent in the stable or pasture environment in the south of England. Injection sites were evaluated at 1 h (immediate phase), 4 h (late phase) and 24 h (delayed phase) and skin responses compared to the response generated by the positive control (histamine) at 1 h. Total numbers of positive reactions and numbers of positive reactions to specific allergens were similar in horses with atopic dermatitis and those with urticaria (P = 0.39). There was a statistically significant difference in the number of reactions observed at different time points, with more positive reactions occurring at 1 h than 24 h (P<0.001), and at 4 h than 24 h (P<0.001). Reading the test at 24 h rarely provides additional information. Reaction patterns were similar to those of previous studies performed in other countries with large numbers of positive reactions reported to mites, dusts and insects. Positive reactions were also common to allergens not previously identified as irritants or common allergens in equids; nettle, daisy, dandelion, horse chestnut, cat, cattle, sheep and pigeon. These allergens may be important causes of allergic dermatitis in equids in the UK; however, further studies should be performed in both normal horses and horses with allergic dermatitis to investigate irritant thresholds and validate these findings. Intradermal testing may be shortened from the conventional 24 h to 4 h without significantly affecting the results of the test.     

Bilateral ovariectomy as a treatment for chronic pyometra in four horses

The objective of this retrospective study was to describe the use of bilateral laparoscopic ovariectomy without hysterectomy for chronic pyometra in horses. Four client-owned horses were included, each having chronic pyometra that was unresponsive to treatment. Bilateral laparoscopic ovariectomy was performed on the horses under standing sedation. A final uterine lavage was performed either 24 hours before or after surgery, with no further treatment of the uterus. No complications were encountered during surgery or post-operatively, and each horse had resolution of the pyometra without recurrence of clinical signs over at least 3 years. All owners were satisfied with the procedure. Following histopathology, one horse was found to be a true hermaphrodite, with one vestigial testis and one ovotestis. Ovariectomy alone was an effective treatment for four horses with chronic pyometra, without complications. Ovarian steroids and abnormal uterine or cervical conformation are important influences in the pathogenesis of pyometra, and removal of the hormone source via ovariectomy should be considered to avoid a more invasive surgery and the potential complications associated with ovariohysterectomy in horses.     

Pemphigus foliaceus in a goat

Abstract A 7-year-old-female goat was referred with a 3-month history of chronic dermatitis, which partially responded to combined corticosteroid and antibiotic therapy. At dermatological examination diffuse alopecia, pustules and crusts were observed on the head, neck, dorsum and perianal area. Dermatophyte culture and skin scrapings were negative. Trichoscopic examination revealed a concurrent infestation with Damalinia caprae , which was successfully treated with ivermectin. Cytological examination of pus from intact pustules revealed nondegenerate neutrophils, absence of bacteria and numerous nucleated, irregularly shaped keratinocytes. Histopathological examination of lesional skin revealed intracorneal pustules containing neutrophils and acantholytic cells, and a mixed cell superficial perivascular dermatitis. Immunohistochemical stains of lesional skin showed intercellular IgG deposits in the spinous layer. Remission of the dermatitis was obtained with injectable dexamethasone-21-isonicotinate, every two months for one year. This is the first report to describe the cytological appearance of impression smears from intact pustules of pemphigus foliaceus in a goat and to document the presence of IgG deposits in lesional skin by means of immunohistochemistry.     

Clinical comparison between a continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane with an interrupted Lembert pattern for one-layer jejunojejunostomy in horses

Reasons for performing study: Although experimental studies have demonstrated differences in performance between methods for handsewn jejunojejunostomy in horses, information on clinical results after different methods of anastomosis are rare. Hypothesis: A continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane would perform better than an interrupted Lembert pattern for jejunojejunostomy in horses. Methods: Data was reviewed on 32 horses that underwent jejunojejunostomy from 1993–2002. Kaplan‐Meier analyses and rates for post operative colic and death were used to compare outcomes after an interrupted Lembert pattern (15 horses with strangulating lesions and 5 horses with nonstrangulating lesions) and a continuous Lembert pattern with membrane (12 horses with strangulating diseases). Results: None of the 32 horses had post operative ileus or post operative endotoxaemia. One horse with a continuous pattern required a repeat celiotomy for anastomotic impaction. Short‐term survivals for the interrupted Lembert were 100% (nonstrangulating lesions) and 93% (strangulating lesions) and for the continuous pattern 92% (all strangulating). Long‐term rates for mortality and colic episodes were less for the continuous Lembert pattern with membrane compared with the interrupted Lembert for strangulating lesions (P<0.05) and were less for strangulating lesions than for nonstrangulating lesions (P<0.05). For strangulating lesions, Kaplan‐Meier analyses yielded a survival probability of 70% for up to 9 years after the interrupted Lembert pattern and 80% for up to 5 years for the continuous Lembert pattern. Conclusions and relevance: Both Lembert patterns performed well in clinical use, although the continuous pattern with the carboxymethylcellulose and hyaluronate membrane had superior long‐term outcomes with less colic and mortality from colic.     

Magnetic resonance imaging changes of the navicular bursa following navicular bursoscopy in seven horses

Navicular syndrome is a multifactorial disease process in horses with multiple structures in the foot contributing to lameness. Surgical debridement is a treatment option for lesions of the navicular bursa and deep digital flexor tendon. This retrospective case series describes the magnetic resonance imaging (MRI) appearance of the navicular bursa following bursoscopy. Seven horses (three being bilaterally affected) with forelimb lameness isolated to the foot, and pre- and post-operative MRI were included. All limbs had concurrent lesions associated with the deep digital flexor tendon, navicular bone, impar ligament, collateral sesamoidean ligament and/or distal interphalangeal joint. All bursae developed or had progression of proliferative bursal tissue following surgery. At recheck MRI, following rehabilitation protocols, almost all horses had improved to resolved lameness with relatively unchanged concurrent lesions despite the navicular bursa appearance worsening. Outcomes for return to work were poor with only two horses going back to the previous level of work.     

Gastric impaction associated with displacement and volvulus of the large colon in seven mature horses

Gastric impaction associated with large colon volvulus (LCV) was identified in seven horses. Right dorsal displacement of the large colon and suspected nephrosplenic entrapment was identified in 2 of the 7 horses as well as LCV with concurrent gastric impaction. All horses underwent surgery for LCV and none survived. Five horses died or were subjected to euthanasia intraoperatively or in recovery. One horse was subjected to euthanasia post operatively due to persistent gastric reflux, following resolution of the gastric impaction. One horse was subjected to euthanasia post operatively due to a suspected gastric rupture, which was confirmed on post mortem examination. It is hypothesised that a large mass in the cranial abdomen, such as a gastric impaction may disrupt the normal anatomical large colon alignment or may cause colonic motility or microbiota alterations, and thus increase the risk of large colon displacement and volvulus.     

Grid keratotomy as a treatment for superficial nonhealing corneal ulcers in 10 horses

OBJECTIVE: To describe the clinical symptoms of 10 cases of superficial nonhealing corneal ulcers in horses and to evaluate the results of grid keratotomy in these patients. DESIGN: Retrospective study. ANIMALS: Ten horses with superficial nonhealing corneal ulceration in one eye. PROCEDURE: The signalment, history and clinical symptoms are reported of 10 patients with superficial nonhealing corneal ulcers during the period from August 2003 to February 2005. Grid keratotomy was performed in all cases. In addition, the surgical procedure of grid keratotomy and response to therapy are described. RESULTS: Horses generally responded well to grid keratotomy (eight cases healed after one grid keratotomy and one horse healed after a second grid keratotomy; one case was not available for follow-up). Only 2/10 had discomfort after treatment and only 2/9 had some degree of scarring after treatment. The healing time, which was known in seven cases, averaged 8.4 days (+/- SD 4). CONCLUSIONS AND CLINICAL RELEVANCE: Grid keratotomy is an appropriate option for treatment of superficial nonhealing corneal ulcers in horses. The procedure is simple to perform. It generally induces a rapid and uncomplicated healing of the cornea. Only in a limited number of cases does a small amount of scarring occur.     

Dental bridging as a treatment for large oral fistulae in two horses

Chronic orocutaneous, oronasal, or orosinus fistulae can be challenging to repair. This report describes placement of a dental bridge as a treatment for oral fistulae and outcome in two horses. A 12-year-old, Westphalian gelding was presented for nasal discharge because of an oromaxillary fistula after dental repulsion of the Triadan 209 4 years earlier. The second case, a 5-year-old Oldenburg mare was presented for an orocutaneous fistula 7 weeks after dental repulsion of the Triadan 208. Both were treated by placing an 8-shaped cerclage wire, inserted through the rostral and caudal interdental spaces and crossing at the level of the missing tooth. Polymethylmethacrylate (PMMA) was then used to seal the fistula. No significant complications occurred during or after the surgery. In both cases clinical signs did not recur. In the first case the dental bridge is currently (5 years after the intervention) in place. In Case 2 the construction was removed after 1.5 years and the fistula had healed completely. This case report suggests that placing a dental bridge composed of cerclage wire and PMMA should be considered as an easy, noninvasive and efficient way to manage large oromaxillary or orocutaneous fistulae.     

Fungal sinusitis resulting in suspected trigeminal neuropathy as a cause of headshaking in five horses

Primary fungal sinusitis was identified in 5 horses displaying signs of headshaking. All 5 horses had fungal plaques adhered to the infraorbital canal (IOC). Headshaking signs were exhibited by 3 horses prior to treatment and 2 horses after treatment. Standing computed tomography (CT) identified erosion of the IOC in the 2 cases in which it was performed. Fungal culture and PCR identified 3 species of fungi, Rhizomucor pusillus, Scedosporium apiospermum and Aspergillus nidulans which have not previously been described as a cause of sinusitis in horses. Surgical debridement followed by topical antifungal therapy was used in all 5 horses. Recurrence of the fungal plaques in 4 horses necessitated further treatment. The headshaking signs and nasal discharge resolved in 3 horses allowing a return to their previous use. Two horses developed persistent headshaking signs despite multiple treatments. Primary fungal sinusitis should be considered as a cause of headshaking signs in horses, due to a suspected trigeminal neuropathy. Computed tomography is valuable in identifying erosion of the IOC which is not identified with conventional radiography. Three out of the 5 cases were treated successfully but permanent resolution of the fungal infection is difficult to achieve once the bone overlying the infraorbital nerve has been eroded.     

Electroencephalographic and cardiovascular variables as nociceptive indicators in isoflurane-anaesthetized horses

OBJECTIVE: To evaluate Fourier-transformed electroencephalographic (EEG) variables, mean arterial blood pressure (MAP) and pulse rate as nociceptive indicators in isoflurane-anaesthetized horses. ANIMALS: Five standardbred and three Norwegian cold-blooded trotter stallions undergoing castration, aged 2-4 years, mass 378-538 kg. MATERIALS AND METHODS: All horses received intravenous (IV) detomidine (10 microg kg(-1) IV) and butorphanol (0.01 mg kg(-1) IV). Additional detomidine (4 microg kg(-1) IV) was administered in the induction area. Anaesthesia was induced with ketamine (2.5 mg kg(-1) IV) and diazepam (40 microg kg(-1) IV), and maintained for 30 minutes with isoflurane (end-tidal concentration of 1.4%) vaporized in oxygen. The electroencephalogram, MAP and pulse rate were recorded for 15 minutes, beginning 5 minutes before skin incision. Differences between the mean values of recordings taken before, and during surgery were calculated and tested for significant differences using a two-sided Student's t-test. RESULTS: A significant rise in MAP and a fall in pulse rate were found. No significant change was found in any EEG variable. CONCLUSION/CLINICAL relevance Of the variables evaluated, MAP seems to be the most sensitive and reliable indicator of nociception in isoflurane-anaesthetized horses.     

Validity of indicators of dehydration in working horses: a longitudinal study of changes in skin tent duration, mucous membrane dryness and drinking behaviour

REASONS FOR PERFORMING STUDY: Dehydration is a serious welfare concern in horses working in developing countries. Identification of a valid and practical indicator of dehydration would enable more rapid treatment and prevention. OBJECTIVES: To examine changes in bodyweight, clinical and blood parameters during rehydration of working horses, identify a 'gold standard' criterion for dehydration and use this to validate a standardised skin tent test, drinking behaviour and mucous membrane dryness as potential field indicators. METHODS: Fifty horses with a positive skin tent test, working in environmental temperatures of 30-44 degrees C in Pakistan, were rested and offered water to drink ad libitum. Bodyweight, clinical and blood parameters, mucous membrane dryness, drinking behaviour and skin tent duration at 6 anatomical locations were measured at 0, 30, 60, 120, 180, 240 and 300 min. RESULTS: Skin tent duration was affected by side of animal (P = 0.008), anatomical location and coat moisture (both P < 0.001). Younger animals had shorter skin tents at all time points (P = 0.007). There was no significant association between plasma osmolality (P(osm)) or water intake and skin tent duration. Horses with a higher P(osm) drank significantly more water (P < 0.001), and had longer (P < 0.001) and more frequent (P = 0.001) drinking bouts. Neither P(osm) nor water intake affected qualitative and semi-quantitative measurements of mucous membrane dryness significantly. CONCLUSIONS AND POTENTIAL RELEVANCE: The standardised skin tent test and measures of mucous membrane dryness investigated in this study were not valid or repeatable indicators of dehydration when compared with P(osm) as a 'gold standard' criterion. The volume of water consumed and the number and duration of drinking bouts were the most reliable guide to hydration status currently available for mature working horses. Offering palatable water to drink ad libitum provides both the diagnosis and the remedy for dehydration in working horses.