English Mastiff Research Articles

From “Husky” to “Bulldog”– behavioural correlates between castration and breed groups in the domestic dog (Canis lupus familiaris)

Neutering dogs is a widespread method and is carried out for various behavioural and husbandry reasons. This study’s main objective is to investigate the behavioural correlations between neutering and the breed of male dogs. In order to possibly find breed-dependent differences in the behaviour of intact and castrated dogs, a differentiation between two clades - the “Huskies“(chow chow, shar pei, akita/shiba inu, alaskan malamute, siberian/alaskan husky) and the “Bulldogs” (german boxer, english/french bulldog, old english mastiff, boston terrier, english bull terrier, staffordshire bull terrier, american staffordshire terrier), based on Parker et al. [1], was made.Using an online questionnaire,, 31 neutered and 37 intact male dogs from the clade “Huskies“ and 30 neutered and 38 intact male dogs from the clade “Bulldogs”, participated in the study (N = 136).The survey included detailed questions on the dogs’ personality and any associated issues as well as a behavioural anamnesis. Further questions relating to four of the “big five” personality dimensions based on the “Budapest questionnaire” by Turcsán et al. from 2011 [2] were also added.The results show, that neutered males from both breed clades more frequently displayed aggression toward humans than intact males (multinomial logistic regression, p = 0.002). When it came to aggression towards other dogs, it was the “Huskies” that differed significantly from the “Bulldogs“(multinomial logistic regression, p = 0.04) with being more aggressive. There were also significant differences in stress-related behaviour depending on castration status and breed (multinomial logistic regression, p < 0.001; Cramer’s V = 0.33) and only the castration status had an impact on the significance (multinomial logistic regression, p < 0.001). The analysis also revealed significance for stress-indicating behaviour with dependence on neutering status (multinomial logistic regression, p < 0.001) and showed that stress as well as uncertainty are significantly more common in neutered dogs depending on breed and neutering status (multinomial logistic regression, p < 0.001; Cramer’s V = 0.42), in that only neutered “Bulldogs“ were stressed, but more “Huskies“ overall.According to the Budapest questionnaire data, the “Bulldog” clade had considerably greater extraversion scores overall (ordinal regression, p < 0.001) than the “Huskies“.Our findings highlight the risks and potential negative effects of neutering. Gonadectomy in no way substitutes for the dog receiving the necessary socialization, training, or bonding. Although in some circumstances it might have a favourable impact on the dog’s behaviour, it should not be seen as a panacea for unwanted behaviour. Given that not all behaviours are influenced by sex hormones, every castration decision must be weighed up individually.

A 3-Year Case Report on an Atopic Patient with a Caninised Monoclonal Antibody Treatment

Abstract A 6-year-old, male, neutered, English Mastiff dog was presented for a second opinion due to chronic pruritus. The patient had been on methylprednisolone and chlorphenamine for four years. The diagnostic investigations included: swabs for bacterial and mycology culture, hair plugs for dermatophyte culture, acetate tape strips and deep skin scrapes, skin biopsies for dermatohistopathology, biochemistry, haematology, endocrinology, serology for canine scabies using enzyme-linked immunosorbent assay (ELISA) testing and serology for allergen specific IgE antibodies. The history and the diagnostics confirmed the diagnosis of canine atopic dermatitis. This case report details the treatment with lokivetmab, which is a caninised monoclonal antibody drug. At periods of flare ups, additional treatments were prescribed, such as systemic glucocorticoids and oclacitinib in order to manage the clinical signs. The treatment showed good response to the overall treatment management during the three year period of this atopic patient.

MRI Features of Presumed Primary Extranodal Lymphoma of the Bulbospongiosus Muscle Causing Stranguria

ABSTRACT Hematopoietic neoplasia is common in dogs, with canine non-Hodgkin lymphomas representing more than 80% of all hematopoietic cancer. However, extranodal infiltration of the skeletal muscle by non-Hodgkin lymphoma is rare in humans and dogs. A 9 yr old neutered male English mastiff presented with a 3 wk history of recurrent stranguria, pelvic limb ataxia, and mild proprioceptive deficits bilaterally, worse in the right pelvic limb. MRI showed an expansile ill-defined lesion within the bulbospongiosus muscle. The lesion had intermediate signal intensity to muscle and fat on T2-weighted imaging and was isointense to unaffected muscle on precontrast T1-weighted imaging. Contrast enhancement was heterogeneous and there was digitate signal alteration within adjacent perilesional fat. Ultrasound examination confirmed a hypoechoic lesion infiltrating the muscle. Cytological examination yielded a diagnosis of high-grade lymphoma. This report provides the first description of MRI findings associated with cytologically confirmed lymphoma of the skeletal muscle in the dog. Although nonspecific, the imaging features strongly correlate with those in the medical literature and lymphoma should be considered a pertinent differential in cases presenting with similar imaging findings.

Osteogenesis and dentinogenesis imperfecta in a four-month-old English mastiff

Osteogenesis imperfecta, also known as ‘brittle bone disease’, is an inherited connective tissue disorder caused by defects in type 1 collagen. The disease results in low bone mass and reduced...

Analysis of risk factors for elbow dysplasia in giant breed dogs.

Identify radiographic risk factors for development of elbow dysplasia in giant breed dogs less than one year of age. Twenty-five giant breed puppies (Bernese Mountain dogs, English Mastiff, and Newfoundland) were studied. Both elbows of each dog were radiographed monthly from two to six months of age, then every other month until radial and ulnar physeal closure, followed two months later by bilateral elbow computed tomography. Radiographic parameters measured included the presence or absence of a separate centre of ossification of the anconeal process (SCOAP), medial coronoid disease (MCD), ununited anconeal process, humeral osteochondrosis, elbow incongruity, as well as the length of the radius and ulna, radius-to-ulna ratio, and date of closure of the radial and ulnar physes. Fifteen dogs completed the study. Two Bernese Mountain dogs were diagnosed with MCD. Risk factors significantly associated with medial coronoid disease included dyssynchronous physeal closure and a decreased radius-to-ulna ratio, both detected between eight to 11 months of age. A separate centre of ossification of the anconeal process was present in 60% of the dogs, and was not a risk factor for development of elbow dysplasia. Transient, dyssynchronous growth of the radius and ulna may be a risk factor for development of MCD in Bernese Mountain dogs. Dyssynchronous physeal closure or decreased radius-to-ulna ratio prior to radiographic closure of the distal ulnar and radial physes warrants further study in Bernese Mountain dogs and other breeds subject to MCD development.

Primary synovial osteochondromatosis of the stifle in an English Mastiff

A two-year-old, 97 kg, male neutered English Mastiff was evaluated for left pelvic limb lameness of five months duration localized to the stifle joint. Following radiographic, computed tomographic and arthroscopic examination, the lameness was subsequently diagnosed as being caused by primary synovial osteochondromatosis. In total, 194 osteochondral bodies were removed using arthroscopy in combination with a mini-arthrotomy. Histology and immunohistochemistry of the loose osteochondral fragments confirmed the diagnosis with a moderately high degree of differentiation and low cellularity. Nuclear staining for Ki-67 revealed decreasing differentiation and increasing cellularity in the fragments. At the 13 months telephone follow-up the owner reported that the dog was free from lameness and had a vastly improved function compared with preoperative levels, although mild lameness did occasionally occur. This is the first report of computed tomography, arthroscopy and immunohistochemistry confirming a case of primary synovial osteochondromatosis in a dog.

Thyroid Function and Infertility in the Dog: A Survey in Five Breeds

In our study, a clinical and reproductive examination was undertaken in 204 dogs of five different breeds. Thyroxine and thyroid-stimulating hormone plasma concentrations were assayed in order to assess the real incidence of hypothyroidism associated with reproductive disease. Among these animals, only two breeds were affected by hypothyroidism (4.5% of the Dogue de Bordeaux and 2.4% of the Leonbergers). Moreover, these animals did not suffer from any reproductive disease. Our study showed also that 70% of the male Dogue de Bordeaux were hypothyroxinemic compared with Great Danes, English Mastiff and Leonbergers whose male population was 100% normothyroidic. We found the same tendency in bitches. In our data, there was no difference in thyroxin plasma concentrations between normo- and hypofertile dogs, but our results were not statistically significant.

An atypical case of Trypanosoma cruzi infection in a young English Mastiff

A case of Trypanosoma cruzi infection in a young English Mastiff from Texas is presented. Clinical signs and laboratory findings included subcutaneous edema, lymphadenopathy, weight loss, and hypoalbuminemia. Cytology of a lymph node revealed numerous amastigotes. No trypomastigotes were observed in buffy coat preparation of peripheral blood, and on histologic evaluation, most organs contained numerous interstitial pseudocysts. Initial serology was positive for both T. cruzi and Leishmania, and immunohistochemistry supported a diagnosis of Leishmania. However, additional serology supported a T. cruzi infection, and cultivation of organisms isolated from a lymph node revealed morphology consistent with T. cruzi. In addition, PCR analysis resulted in a 504 bp fragment with 99% homology to a flagellar protein of T. cruzi. Although uncommon, autochthonous cases of both T. cruzi and Leishmania have been reported in the United States. Clinical signs observed with both diseases can show many similarities, cytology may be indistinguishable, as in this case, and serological cross-reactivity is common. This case demonstrates an unusual presentation of T. cruzi and the use of multiple testing strategies to support its diagnosis.

Femoral Neuropathy in a Dog with Iliopsoas Muscle Injury

To report femoral nerve dysfunction caused by focal iliopsoas muscle injury and treated by performing tenectomy of the muscle insertion. Case report. A 4-year-old, castrated male, English Mastiff. Iliopsoas muscle injury caused femoral nerve deficits and severe pain. Focal injury was not detected by ultrasonography or computed tomography but was visible on magnetic resonance (MRI) images. Tenectomy of the insertion of the iliopsoas muscle relieved signs of pain. Femoral nerve dysfunction may occur with iliopsoas muscle injury. Iliopsoas muscle injury should be considered in patients with hip pain and MRI is a useful test for diagnosis. Tenectomy may be indicated for relief of chronic iliopsoas muscle pain.

A Naturally Occurring Mutation of the Opsin Gene (T4R) in Dogs Affects Glycosylation and Stability of the G Protein-coupled Receptor

Rho (rhodopsin; opsin plus 11-cis-retinal) is a prototypical G protein-coupled receptor responsible for the capture of a photon in retinal photoreceptor cells. A large number of mutations in the opsin gene associated with autosomal dominant retinitis pigmentosa have been identified. The naturally occurring T4R opsin mutation in the English mastiff dog leads to a progressive retinal degeneration that closely resembles human retinitis pigmentosa caused by the T4K mutation in the opsin gene. Using genetic approaches and biochemical assays, we explored the properties of the T4R mutant protein. Employing immunoaffinity-purified Rho from affected RHO(T4R/T4R) dog retina, we found that the mutation abolished glycosylation at Asn(2), whereas glycosylation at Asn(15) was unaffected, and the mutant opsin localized normally to the rod outer segments. Moreover, we found that T4R Rho(*) lost its chromophore faster as measured by the decay of meta-rhodopsin II and that it was less resistant to heat denaturation. Detergent-solubilized T4R opsin regenerated poorly and interacted abnormally with the G protein transducin (G(t)). Structurally, the mutation affected mainly the "plug" at the intradiscal (extracellular) side of Rho, which is possibly responsible for protecting the chromophore from the access of bulk water. The T4R mutation may represent a novel molecular mechanism of degeneration where the unliganded form of the mutant opsin exerts a detrimental effect by losing its structural integrity.

Canine models of ocular disease: outcross breedings define a dominant disorder present in the English mastiff and bull mastiff dog breeds.

Progressive retinal atrophies (PRA) are a heterogeneous group of inherited eye diseases common to both dogs and man. Over 100 individual canine breeds display some sort of retinal degeneration, making the dog an extremely valuable resource both for finding the genetic determinants of inherited blindness and for developing naturally occurring animal models that mimic human disease. Progressive retinal atrophies within the English mastiff displayed an ambiguous mode of inheritance. By conducting outcross matings between affected English mastiffs and normal animals from other breeds, the mode of inheritance was confirmed as dominant. This directed candidate gene analysis and led to identification of two synonymous mutations and one nonsynonymous mutation within the canine rhodopsin gene. The nonsynonymous mutation (T4R) is the cause of PRA in the English mastiff, and a test was developed to investigate its presence in 17 additional breeds. Testing of PRA-affected animals from 16 breeds revealed that none carry the T4R mutation, indicating a different cause of PRA. Analysis of two affected bull mastiffs revealed one heterozygote (+/T4R) and one homozygous normal individual (+/+). These findings suggest that the genetic origin of PRA is often breed specific and underline the value of outcross mating to circumvent problems that act to mask the mode of inheritance.

Naturally occurring rhodopsin mutation in the dog causes retinal dysfunction and degeneration mimicking human dominant retinitis pigmentosa.

Rhodopsin is the G protein-coupled receptor that is activated by light and initiates the transduction cascade leading to night (rod) vision. Naturally occurring pathogenic rhodopsin (RHO) mutations have been previously identified only in humans and are a common cause of dominantly inherited blindness from retinal degeneration. We identified English Mastiff dogs with a naturally occurring dominant retinal degeneration and determined the cause to be a point mutation in the RHO gene (Thr4Arg). Dogs with this mutant allele manifest a retinal phenotype that closely mimics that in humans with RHO mutations. The phenotypic features shared by dog and man include a dramatically slowed time course of recovery of rod photoreceptor function after light exposure and a distinctive topographic pattern to the retinal degeneration. The canine disease offers opportunities to explore the basis of prolonged photoreceptor recovery after light in RHO mutations and determine whether there are links between the dysfunction and apoptotic retinal cell death. The RHO mutant dog also becomes the large animal needed for preclinical trials of therapies for a major subset of human retinopathies.

Teaching Old Dogs New Tricks: The English Mastiff and the Anglo‐American Experience

Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsMark A. MastromarinoThe author is a Ph.D. candidate at the College of William and Mary. He received the Phi Alpha Theta Essay Prize in 1985 for this paper and wishes to acknowledge the help of Dr. James Axtell.

Two Uncollected Reviews by Hawthorne

A Lion's Whelp was put on board a Guinea Ship bound to America as a Present to a Friend in that Country: It was tame and harmless as a Kitten, and therefore not confined, but suffered to walk about the Ship at Pleasure. A stately, full-grown English Mastiff, belonging to the Captain, despising the Weakness of the young Lion, frequently took it's Food by Force, and often turned it out of it's Lodging Box, when he had a Mind to repose therein himself. The young Lion nevertheless grew daily in Size and Strength, and the Voyage being long, he became at last a more equal Match for the Mastiff; who continuing his Insults, received a stunning Blow from the Lion's Paw that fetched his Skin over his Ears, and deterred him from any future Contest with such growing Strength; regretting that he had not rather secured it's Friendship than provoked it's Enmity.