Cartilage Degeneration of the Metacarpal Condyle and Enthesopaties of The Collateral Ligaments of Equine Metacarpophalangeal Joint.

Articular degeneration can be characterized by fibrillation and eburnation of the articular layers of the metacarpophalangeal (MP) joint. Structural changes within the articular joint predispose the development of osteophytes, enthesophytes and, in many cases is associated with changes the collateral ligaments of the MP joint. The aim of the present study was to investigate the relationship between degenerative processes of the articular cartilage and the enthesopathies of collateral ligaments (superficial or deep portion) of the equine MP joint, using radiographic, ultrasonographic and anatomopathological exam, as well as establishing their sensitivity. Thirty equine forelimbs were selected from animals that died due to various clinical conditions with an average age of 5.7 years which came from a private clinic or sent to the Laboratory of Veterinary Pathology of UFSM. The specimens were placed in a hydraulic press and submitted to radiographic evaluation of the MP joint (lateromedial, flexed lateromedial, dorsopalmar, dorsolateral-palmaromedial oblique 450 and dorsomedial-palmarolateral oblique 450 projections). Transversal and longitudinal ultrasound images of the dorsal and collateral aspect of the MP joint were obtained using a Sonosite Edge machine with a 5 to 10 MHz linear transducer. Subsequently, the specimens were sent for gross and histopathological examination. A highly positive correlation (P value <.001) was observed between ultrasonographic and macroscopic techniques, showing a relationship between the cartilaginous degenerations of the MP joint and the medial and lateral LC enthesopathies.

Histologic Evaluation of Palmar Digital Nerves after Perineural Injection of 2% Ammonium Chloride in Miniature Horses.

Neurolytic compounds are widely used by equine practitioners for the management of lameness, mostly related to the foot. The present study aimed to evaluate the neurotoxicity of 2% ammonium chloride (2% AC) applied adjacent to the palmar digital nerves in six miniature horses. The 2% AC and 0.9% saline solution were randomly injected into three and one palmar digital nerve of each horse, respectively. Nerve samples were collected by neurectomy performed under general anesthesia at 5, 12, 19, 35, 47, and 62 days after treatment, with one horse per day of surgery. The inflammatory reaction to perineural injection was evaluated by an increase of pastern superficial skin temperature through thermography 24 hours after treatments. Histological lesions were classified as absent, mild, moderate, and severe Wallerian degeneration. An increase of 2.43 ± 0.79°C and 1.69 ± 0.55°C was observed in the 2% AC and control groups, respectively (P > .05). Moreover, histologic lesions were observed after perineural injection of 2% AC (severe, n = 5/18; moderate, n = 4/18; mild, n = 5/18; and absent, n = 4/18) and saline solution (moderate, n = 3/6; mild, n = 1/6; and absent, n = 2/6) (P = .46). The 2% AC demonstrated to be as safe as 0.9% saline solution, producing mild to severe Wallerian degeneration for up to 62 days after injection with no interference in further neurectomy.

Digit innervation of the thoracic limb of Criollo horses: Anatomical description and consequences to perineural blocks.

Criollo horse breeding is an important economic activity in South America. Because of their athletic performance, these animals tend to show great incidence of musculoskeletal disorders, many of them diagnosed by means of perineural blocks. However, incorrect interpretation of these blocks may be due to anatomical differences in nerve distribution. The objective of this study was to describe the innervation of the digit region of thoracic limbs in Criollo horses, in order to improve the interpretation of tests for claudication diagnosis based on nerve block. Thirty thoracic limbs from Criollo horses were dissected. It could be observed that in 90% of the limbs, dorsal branches of the palmar nerve originated proximally to the proximal sesamoid bone. In 93% of the cases, the palmar digital nerve and the dorsal branches communicated; in 87% of the cases, communication between branches of the dorsal branch was observed; and in 27% (8/30) of the limbs, the palmar metacarpal nerve and the dorsal branch presented communications. None of the specimens showed complete symmetry in the distribution of nerves in contralateral limbs. The high frequency of communication between the nerves may be a particularity of the Criollo breed that may interfere with the interpretation of perineural blocks. Based on the anatomical position, it may be inferred that divergent results in Criollo horses may occur when abaxial sesamoid nerve block is used. Palmar digital nerve block may be less influenced by these variations, provided it is performed as distal as possible from the ungular cartilage.

Objective evaluation versus subjective evaluation of flexion tests in the pelvic limb of horses / Avaliação objetiva versus avaliação subjetiva dos testes de flexão no membro pélvico de cavalos

The agreement between subjective and objective evaluation methods was studied to identify claudication in the pelvic limbs of horses before and after flexion tests were performed. Twenty-nine horses were equipped with a wireless system of inertial sensors and evaluated during seven times while trotting. Videos were recorded to be evaluated by three veterinarians, with different levels of experience, to evaluate the agreement between the two different methods and between the evaluators. The evaluators and the objective evaluation had a low rate of agreement, with the exception of moderate agreement between the objective evaluation and evaluator 1 to identify lameness after the left total flexion and moderate agreement in evaluating the response to the tests, between objective evaluation and evaluator 2, after right distal flexion. This shows that there was a low agreement among the evaluators and between them and the objective evaluation for identifying lameness, measuring the degree of lameness and the response to the flexion tests.(AU)

A concordância entre métodos de avaliação subjetiva e objetiva foi estudada para identificar claudicação nos membros pélvicos antes e após a realização dos testes de flexão. Vinte e nove cavalos foram equipados com um sistema de sensores inerciais sem fio e avaliados durante sete momentos enquanto troteavam. Vídeos foram gravados para serem avaliados por três veterinários com diferentes níveis de experiência, a fim de avaliar a concordância entre os dois métodos diferentes e entre os avaliadores. Os avaliadores e a avaliação objetiva tiveram uma baixa taxa de concordância, com exceção de uma moderada concordância entre avaliação objetiva e avaliador 1 para identificar claudicação após o teste de flexão total esquerdo e uma moderada concordância na avaliação da resposta aos testes, entre avaliação objetiva e avaliador 2, após o teste de flexão distal direito. Isso demonstra que houve uma baixa concordância entre os avaliadores e entre estes e a avaliação objetiva para identificação da claudicação, mensuração do grau de claudicação e resposta aos testes de flexão.(AU)

Prevalência de alterações ósseas no tarso de potros Crioulos de até vinte e seis meses de idade / Bone changes prevalence in the tarsus of Crioulo yearlings up to 26 months of age

Com o objetivo de definir a prevalência de alterações ósseas no tarso, foram examinados radiograficamente 77 potros da raça Crioula, com até 26 meses de idade e a relação das lesões com parâmetros biométricos e de manejo. Os animais foram divididos em dois grupos por idade: G1, incluindo potros de nove a 18 meses (34/77); e G2, com animais de 19 a 26 meses (43/77). Os animais também foram divididos pelo tempo de preparo para exposição morfológica em GC, grupo controle (29/77), os animais sem preparo para exposição; e GI, grupo incentivo (48/77), animais com preparo médio de 4,55 meses, e foram separados por sexo em machos (46/77) e fêmeas (31/77). Os dados foram coletados em 24 propriedades de criação ou centros de treinamento/preparo do estado do Rio Grande do Sul. Lesões radiograficamente visíveis foram observadas em 79,2% (61/77) dos animais, 80,4% dos machos, 77,4% das fêmeas, 77,3% dos animais do GC, 79,2% dos animais do GI, 86,7% dos animais do G1 e 76,7% dos animais do G2. O peso médio dos potros de 10 a 12 meses de idade foi 293,2kg, representando 71,3% do peso adulto; o peso médio dos animais com idade de 19 a 26 meses foi de 360,5kg (87,6% do peso adulto); do GC foi de 288,9kg (70,2% do peso adulto); e do GI 341,9kg (83,1% do peso adulto), apesar da idade média dos dois últimos grupos ter sido de apenas 16,8 e 19,0 meses, respectivamente. Observou-se relação positiva entre o aumento do escore corporal dos animais (P=0,01; r=0,3), do tempo de preparo dos animais para exposição morfológica (P=0,0001; r=0,7) e do escore de deposição de gordura na crista do pescoço (P=0,02; r=0,3) com as lesões radiográficas observadas no tarso dos potros. Vários fatores podem estar envolvidos na osteoartrite társica distal, entretanto, em cavalos Crioulos, o fator mais importante presente nas criações foi o sobrepeso.

Aiming to evaluate the prevalence of bone changes, radiographs were taken from both tarsal joints of 77 Crioulo yearlings, up to 26 months of age. The degree of changes was correlated with biometric parameters and management practices. The animals were separated into six groups, according to age: G1, including nine to 18 months old foals (34/77) and G2, with animals between 19 to 26 months of age (43/77); preparation time to halter class shows: GC, including animals who were not submitted to any preparation (29/77), and GI, consisting of young horses prepared to participate (average of 4.55 months of preparation time) in halter shows (48/77); and gender: colts (46/77) and fillies (31/77). Data were obtained from 24 breeding farms or training centers in Rio Grande do Sul state. Results showed that 79.22% (61/77) of the animals presented some degree of radiographically visible lesions, being 80.4% of males, 77.4% of females, 77.3% in GC, 79.2% in GI, 86.7% in G1 and 76.7% in G2. The mean body weight of the 10 to 12 month old yearlings (G1) was 293.2kg, representing 71.3% of the breed's mature weight and that of the 19 to 26 month old (G2) animals was 360.5kg (87.6% of the mature weight). The mean body weight of the GC was 288.9kg (70.2% of the mature weight) and of GI was 341.9kg (83.1% of the mature weight), although the average age of both groups was 16.8 and 19.0 months, respectively. A significant relationship was found between the animal's body condition score (P=0.01; r=0.3), time of preparation to halter class shows (P=0.0001; r=0.7), and neck crest score (P=0.02; r=0.3), and degree of the radiographic lesions found in the tarsi. Several factors can be involved in the development of distal tarsal juvenile osteoarthritis; however, in Crioulo breeding farms, the most important factor present was the horse's overweight.

Acute myonecrosis in horse caused by Clostridium novyi type A.

The objective of this study was to describe the first report involving a case of equine acute myonecrosis caused by C. novyi type A with an emphasis on clinical signs, the pathological and bacteriological analysis, and molecular identification of the microorganisms as the key of the definitive diagnosis.

Acute myonecrosis in horse caused by Clostridium novyi type A

The objective of this study was to describe the first report involving a case of equine acute myonecrosis caused by C. novyi type A with an emphasis on clinical signs, the pathological and bacteriological analysis, and molecular identification of the microorganisms as the key of the definitive diagnosis.

Spi2 gene polymorphism is not associated with recurrent airway obstruction and inflammatory airway disease in thoroughbred horses

The aim was to detect the presence of polymorphisms at exons 1, 2, 3 and 4 of the Spi2 gene, and evaluate a possible association between them and recurrent airway obstruction (RAO) or inflammatory airway disease (IAD) in thoroughbred horses, through single-strand conformational-polymorphism (SSCP) screening. Although polymorphism was not detected in exons 1, 2 and 3, three alleles and six genotypes were identified in exon 4. The frequencies of allele A (0.6388) and genotype AA (0.3888) were higher in horses affected by RAO, although no association was found between polymorphism and horses with either RAO or IAD.