Effect of dorsal laminectomy and dorsal annulectomy with partial lumbosacral discectomy on the volume of the lateral intervertebral neuroforamina in dogs when the lumbosacral junction is extended.

OBJECTIVE: To determine the effect of dorsal annulectomy and partial discectomy on the volume of the lumbosacral lateral intervertebral neurovascular foramina (intervertebral foramina) in canine cadavers during extension of the lumbosacral junction. STUDY DESIGN: Ex vivo experiment. SAMPLE POPULATION: Lumbosacral specimens from 10 large breed dogs euthanatized for reasons unrelated to lumbosacral disease. METHODS: The lumbosacral specimens were clamped in a wooden jig and scanned using computed tomography (CT) with the lumbosacral junction in a neutral position and loaded in extension using a tensioning device. The 3-dimensional volumes of the lumbosacral intervertebral neurovascular foramina were measured and the extent of any disc degeneration was determined from the CT data. A limited dorsal laminectomy of S1 and a dorsal LS annulectomy and partial discectomy were then performed. The lumbosacral specimens were remounted into the jig and loaded into extension at the same tension and were re-scanned. Measurements of intervertebral foraminal volume were then repeated. RESULTS: The mean volume of the lumbosacral foramina (n = 20) was 381 mm3 in neutral (unloaded) positioning and 137 mm3 when loaded in extension. Following dorsal annulectomy, the mean volume was significantly reduced by a mean of 28% to 98 mm3 (P < .01). The foraminal volume was reduced in 19/20 lumbosacral foramen, with the post-annulectomy volume ranging from 31% to 97% of the pre-annulectomy volume (3%-69% reduction). CONCLUSIONS: This study suggests that a dorsal annulectomy with partial discectomy may induce further dynamic collapse of the lumbosacral articulation in the dog.

Computed tomographic evaluation of dynamic alteration of the canine lumbosacral intervertebral neurovascular foramina.

OBJECTIVE: To develop a computed tomographic (CT) method to measure the volume of the lumbosacral intervertebral neurovascular foramina (IVF) in dogs, and determine the effect of the range of motion of the lumbosacral (LS) junction on this measurement in German shepherd dogs (GSDs) with degenerative lumbosacral stenosis (DLSS) compared to unaffected controls. STUDY DESIGN: In vivo analysis and retrospective case series. SAMPLE POPULATION: Twenty-four working Police GSDs, 12 diagnosed with DLSS and 12 unaffected by DLSS were compared to 10 Greyhounds without DLSS. METHODS: Three-dimensional renderings of CT data were used to measure the lumbosacral foraminal volume of dogs positioned in dorsal recumbency with the LS junction alternately positioned in extension, neutral position, and flexion. RESULTS: Volumetric analysis of the IVF was found repeatable for the extended and neutral positions (interclass correlation coefficient of 0.89 and 0.8, respectively). The mean lumbosacral IVF volume was decreased by 74% between LS flexion and extension in Greyhounds, compared to 79 and 85% reductions in GSDs unaffected and affected by DLSS, respectively. The lumbosacral IVF volume was decreased by 23% when comparing extended to neutral LS positions in Greyhounds, 29% in unaffected GSDs, and 31% in affected GSDs. IVF volumes were smaller in affected GSDs compared to unaffected GSDs (P < .05) and Greyhounds (P < .01). CONCLUSIONS: Positioning the LS junction in full extension decreases the volume of the lumbosacral IVF. This dynamic narrowing was more pronounced in GSDs with signs of DLSS than in GSDs not overtly affected by DLSS.

X-linked myotubular myopathy associated with an MTM1 variant in a Maine coon cat.

OBJECTIVE: Describe the clinical course and diagnostic and genetic findings in a cat with X-linked myotubular myopathy. CASE SUMMARY: A 7-month-old male Maine coon was evaluated for progressively worsening gait abnormalities and generalized weakness. Neurolocalization was to the neuromuscular system. Genetic testing for spinal muscular atrophy (LIX1) was negative. Given the progressive nature and suspected poor long-term prognosis, the owners elected euthanasia. Histopathology of skeletal muscle obtained post-mortem disclosed numerous rounded atrophic or hypotrophic fibers with internal nuclei or central basophilic staining. Using oxidative reactions mediated by cytochrome C oxidase and succinic dehydrogenase, scattered myofibers were observed to have central dark staining structures and a "ring-like" appearance. Given the cat's age and clinical history, a congenital myopathy was considered most likely, with the central nuclei and "ring-like" changes consistent with either centronuclear or myotubular myopathy. Whole genome sequencing identified an underlying missense variant in myotubularin 1 (MTM1), a known candidate gene for X-linked myotubular myopathy. NEW OR UNIQUE INFORMATION PROVIDED: This case is the first report of X-linked myotubular myopathy in a cat with an MTM1 missense mutation. Maine coon cat breeders may consider screening for this variant to prevent production of affected cats and to eradicate the variant from the breeding population.

Association between skin surface pH, temperature and Staphylococcus pseudintermedius in dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis.

Secondary bacterial infection is a frequent complication in lesional skin of dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis (ImR-LPP). However, the influence of skin pH and temperature in determining the composition of the cutaneous microflora at lesional sites has not been investigated. The association between ImR-LPP and pedal skin temperature, pH and Staphylococcus pseudintermedius isolates was thus evaluated. Temperature and pH were measured in 20 dogs with ImR-LPP and in 30 clinically healthy control dogs, and S. pseudintermedius was cultured from interdigital and palmoplantar swabs in both groups and scored semi-quantitatively for bacterial growth. In the ImR-LPP group, mean skin pH was slightly, but significantly, higher at both interdigital and palmoplantar sites. Staphylococcus pseudintermedius was isolated more frequently, and scores for bacterial growth were also significantly higher. However, mean skin temperatures were not significantly different from those in the control group. The isolation of S. pseudintermedius was significantly associated with ImR-LPP, with the single exception of isolates on Columbia blood agar from the palmoplantar region. However, pH and temperature were not significantly associated with the disease, and were not associated with the isolation of S. pseudintermedius at most sites sampled. Staphylococcus pseudintermedius was not isolated from all feet sampled in dogs with ImR-LPP. Taken together, these data would suggest that S. pseudintermedius infection is most likely to be a secondary phenomenon in dogs with ImR-LPP, and that changes in skin pH and temperature are not significant risk factors for this disease.

Evidence for the Continued Occurrence of Chorioretinopathy in Working Sheep Dogs in New Zealand in 2010.

A study in conducted 1987 by Hughes et al., found that 39% of working sheep dogs had multifocal retinitis. One of the identified causes was ocular larval migrans, which were a result of migrating ascarid larvae. Since that paper was published, anthelmintic use in farm dogs has been highly recommended. There has been no follow-up study to determine if fundic lesions are still present. The current study aimed to investigate the prevalence of chorioretinopathy in working sheep dogs in the South-West, Waikato, New Zealand. This was a cross-sectional study of 184 working sheep dogs and 51 owners, undertaken in 2010 with owners sampled from New Zealand's South-West Waikato and Tux North Island Dog Trial Championship. Two-way tables were used to explore the relationship between variables. Significance of association was assessed using a Chi-squared or Fisher exact test as appropriate, with a p-value of <0.05 considered significant. Overall prevalence of chorioretinopathy in the working sheep dogs was 44/184 (24%). A significantly higher prevalence of chorioretinopathy was shown in dogs with increasing age, from 2 years to >8 years (p = 0.0007) and in males (p < 0.0001). This study concluded that lesions of chorioretinopathy are still present in working sheep dogs in New Zealand.

Cutaneous infiltrates and peripheral blood immune responses in dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis.

This study characterizes T- and B-lymphocyte responses in the peripheral blood and lesional skin of dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis (ImR-LPP), a term previously proposed to denote a subpopulation of dogs with idiopathic pododermatitis. T-cell (CD3+, CD4+ and CD8+ ) and B-cell (CD21+) counts were significantly increased in both the epidermis and dermis of lesional ImR-LPP skin compared with that in pedal skin from healthy controls. CD3+ , CD4+, CD8+ and CD21+ cells were commonly observed in perivascular sites in the superficial dermis, periadnexally, beneath the dermal-epidermal (DE) junction and in the epidermis of lesional ImR-LPP skin. The CD8+ /CD3+ T-cell ratio in peripheral blood was significantly increased in the ImR-LPP group (0.42 versus 0.35 in controls). Serum IgA, IgG and IgM concentrations were all significantly elevated in affected dogs. Lymphocyte stimulation indices in ImR-LPP dogs were comparable with control levels except for a lower response to ionomycin (6.0 versus 11.1). Dogs with ImR-LPP had a higher incidence and mean (semi-quantitative) score for IgA, IgG and IgM deposits in the epidermis, and a significantly increased incidence of dermal IgA+, IgG+ and IgM+ mononuclear inflammatory cells. The results indicate that upregulated T- and B-lymphocyte responses may contribute to the pathogenesis of the skin lesions observed in dogs with ImR-LPP.

Antimicrobial resistance profiles and mechanisms of resistance in Campylobacter jejuni isolates from pets.

The presence of antimicrobial resistance in 51 Campylobacter jejuni isolates obtained from cats and dogs was determined by E-testing. Resistance to nalidixic acid (37.3% of isolates), ciprofloxacin (19.6%), tetracycline (13.7%), ampicillin (13.7%), erythromycin (11.8%), and chloramphenicol (5.9%) was detected. Resistance to two antimicrobials or more was present in 31.4% of isolates, and one isolate was resistant to all six antimicrobials. Of the isolates with ciprofloxacin and/or nalidixic acid resistance, 54.5% had the gyrA substitution Thr-86-Ile on sequencing. The tet o gene was detected in 75.0% isolates with high-level resistance to tetracycline. With the observed antimicrobial resistance in C. jejuni isolates from pets in this study, and the detection of identical mechanisms for quinolone and tetracycline resistance in pets and humans, pets should be considered a potential source of (multi)resistant C. jejuni infections in humans.

Parasitic Nematode and Protozoa Status of Working Sheepdogs on the North Island of New Zealand.

Working farm dogs in New Zealand may have a high parasitic challenge because of access to raw meat and close contact with other dogs. This cross-sectional study aimed to estimate the percentage of dogs with gastrointestinal nematode and protozoan parasite lifecycle stages present in their feces and to identify factors associated with the presence of parasites. A single researcher collected information about the dogs and their management via a questionnaire, body condition scored (BCS) the dogs, and collected fecal samples to determine the parasite burden. Fecal samples were collected from 171 dogs and 40% (95% CI 33.0% to 47.7%) contained parasite ova or (oo)cysts. There was no association between BCS and the presence of nematodes and parasites (p = 0.74) in the feces. The percentage of dogs with parasites present in their feces was not associated with BCS or the frequency with which anthelmintic drugs were reportedly administered (p = 0.61). The high percentage of dogs with parasites are of concern for the health of the dogs and their owners, given the zoonotic potential of some parasites. Further, research should also focus on understanding why reporting giving anthelmintic drugs at least every three months did not eliminate the infection.

Canine pododermatitis and idiopathic disease.

Pododermatitis is a common inflammatory skin disease of dogs. As pedal lesions are reported in many canine dermatoses, a methodical series of diagnostic tests is required to establish the underlying aetiology. However, laboratory/ancillary investigations may prove unrewarding, prompting a diagnosis of idiopathic disease. Various hypotheses have been proposed to explain the pathogenesis of idiopathic pododermatitis including pedal conformation, trauma, immunosuppression, bacterial infection, furunculosis and dermal granuloma formation. Idiopathic pododermatitis accounts for 0.5% of all dermatology referrals to the authors' clinic. A sub-group within this population is characterised histopathologically by epidermal hyperplasia, hyperkeratosis, spongiosis, dermal oedema and perivascular aggregates of lymphocytes and plasma cells. The term lymphocytic-plasmacytic pododermatitis (LPP) has previously been proposed to reflect the histological appearance of such lesions. Affected dogs, although systemically well, characteristically have pruritus, erythema, swelling, pain and alopecia of the feet. Although non-responsive to antimicrobial therapy, antiparasitic agents and elimination diets, these dogs typically respond well to immunomodulatory therapy.

A study of dendritic cell and MHC class II expression in dogs with immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis.

The term immunomodulatory-responsive lymphocytic-plasmacytic pododermatitis (ImR-LPP) has previously been proposed to denote a sub-population of dogs with idiopathic pododermatitis. The objective of this study was to investigate dendritic cell (DC) and MHC class II antigen expression in lesional skin of dogs with ImR-LPP (n=47). Median epidermal CD1c(+) cell counts were 37.8 and 12.5 mm(-1) in ImR-LPP dogs and healthy controls (n=27), respectively (P<0.01), while the corresponding dermal cell counts were 180.9 and 45.0 mm(-2), respectively (P<0.01). Intra-epidermal clusters of DCs were observed in 18/47 dogs with ImR-LPP. Median epidermal MHC class II(+) cell counts were 32.5 and 10.5 mm(-1) in ImR-LPP dogs and healthy controls, respectively (P<0.01), while the corresponding dermal cell counts were 216.9 and 46.9 mm(-2), respectively (P<0.01). Dermal MHC class II(+) staining was primarily associated with DCs (47/47 dogs), mononuclear inflammatory cells (45/47), fibroblast-like cells (19/47) and vascular endothelium (14/47). The DC hyperplasia and increased MHC class II expression in lesional ImR-LPP skin are consistent with enhanced antigen presentation, and suggest that both parameters may contribute to the pathogenesis of ImR-LPP through the priming and activation of CD4(+) T cells. Equally, it is possible that the enhanced DC numbers observed in this study may contribute to the immunoregulation of steady-state pathology in lesional ImR-LPP skin through additional expanded, although as yet unresolved, mechanisms.

Medium-Term Outcome and CT Assessment of Lateral Foraminotomy at the Lumbosacral Junction in Dogs with Degenerative Lumbosacral Stenosis.

OBJECTIVE: This article aims to report the medium-term clinical outcome and assess persistence of enlargement of the lumbosacral lateral intervertebral neurovascular foramen using computed tomography (CT) volumetric analysis in dogs following lateral foraminotomy. MATERIALS: Six dogs that underwent lumbosacral lateral foraminotomy on one or both sides were evaluated with CT prior to, immediately postoperatively (n = 2) and at 12 to 44 months of follow-up. Five out of six dogs had successful clinical outcomes with alleviation of pain and increased levels of activity, according to subjective assessment. Immediate postoperative CT volumetric analysis of the lateral intervertebral neurovascular foramina in two dogs indicated a 650 to 800% increase in volume in extension achieved by foraminotomy (four foramens). At subsequent follow-up, bone regrowth had occurred with reduction in foraminal volume, though in both dogs foraminal volume remained higher than preoperative values. Follow-up CT at a median of 24 months postoperatively indicated a mean 335% increase in volume of the lumbosacral lateral intervertebral neurovascular foramina in extension compared with the preoperative foraminal volume. The follow-up volume was substantially greater than the presurgical volume in four out of six dogs. CLINICAL SIGNIFICANCE: In this limited case series, lateral foraminotomy achieved persistent enlargement of the lumbosacral lateral intervertebral neurovascular foramen in the medium term, but osseous regrowth at the site was demonstrated which may limit the effectiveness of lateral foraminotomy in the longer term. One of two working dogs had recurrent clinical signs that necessitated further surgery.

Undergraduate veterinary education at University College Dublin: a time of change.

The final-year Bachelor of Veterinary Medicine (MVB) class of 2005 were the first cohort of students to complete the new curriculum at the Faculty of Veterinary Medicine, University College Dublin (UCD). The new curriculum is a fundamental departure from the traditional curriculum that had served the veterinary profession in Ireland over many years. The change was not a precipitate action but the outcome of a prolonged and thorough examination of the realities of veterinary medicine, its science and its art, in the first decade of a new millennium. Over recent decades, rapid and fundamental changes have been witnessed in the economic, cultural, and ethical environment in which the veterinary profession operates, and these changes, coupled with the "information explosion," dictated an examination of the educational paradigm. The new curriculum exposes the first-year class to veterinary information technology and problem-based learning (PBL). In the second year, students are instructed in clinical examination, history taking, and client communication skills, in addition to further exposure to PBL. The third and fourth years are now systems-based, with coordinated input from microbiologists, parasitologists, pathologists, and clinicians in teaching each body system. The first lecture-free final year in the 104-year history of veterinary education in Ireland consists of clinical rotations and a four-week elective pursued within the faculty or at other recognized institutions. Students must also complete a minimum of 24 weeks' extramural studies (EMS). Critically, the development and assessment of all courses in the new undergraduate degree program has been driven by carefully thought out learning outcomes. The new curriculum will provide graduates with the essential knowledge and skills required for entry into the veterinary profession. Society expects these qualities from veterinarians in the interests of the communities they serve during their professional careers. In addition, the curriculum should foster the ability to adapt to changing circumstances, instill the desire and ability to work in teams, and develop life skills. It is hoped that the academic innovations will arouse the intellectual curiosity and commitment to lifelong learning that future graduates will require if they are to retain the confidence of the society in which they work in the future.

Angiostrongylus vasorum: a real heartbreaker.

Recent reports suggest that the canine heartworm Angiostrongylus vasorum is expanding from traditional endemic foci in several parts of the world. We are ill placed to judge the causes and potential consequences of this expansion because of a lack of knowledge about fundamental aspects of the biology of the parasite. We call for a renewed focus on this important but neglected nematode.

Non-accidental injury in companion animals in the Republic of Ireland.

: Non-accidental injury (NAI), animal abuse and "battered pet" syndrome are terms used to identify "the intentional harm of an animal". The terms include, but are not limited to, wilful neglect, inflicting injury, pain or distress, or malicious killing of an animal. Three categories of abuse are recognised: physical, sexual and neglect.A postal survey was conducted to determine the extent to which NAI was recognised by veterinary surgeons in urban, semi-rural and rural veterinary practices in the Republic of Ireland. The questionnaire was sent to 600 veterinarians; completed submissions were received from 115 respondents (19.2%).The occurrence of NAI was acknowledged by 106 (92.2%) of the respondents and cases had been seen by 50 (43.3%) of them, comprised of 36.2% of urban veterinary surgeons from rural towns and of 82% of urban practitioners. In 59% of cases the client indicated the injury was non-accidental; 39 (67.2%) of the 58 reported cases involved a single event. Signs that made veterinary surgeons suspicious of NAI included inconsistent history, untreated injuries, recurring injuries, meekness of the animal, suspicious behaviour of the owner and injuries consistent with abuse. The types of injuries observed included burns, lacerations, gunshot wounds, poisoning, injury to genitalia, bruising and fractures.The findings of this study are comparable with those from other countries. Most but not all veterinary surgeons in Ireland recognise NAI and animal abuse is of significant concern in rural and urban communities as evidenced by this survey of practising veterinary surgeons.

Trans-pinnal movement of methimazole: an in vitro study showing that methimazole can cross from the inner to outer pinna of cats.

OBJECTIVES: The aim of the study was to determine if methimazole applied in a transdermal formulation to the internal pinna will cross to the external pinna in an in vitro Franz cell model. METHODS: The ears from six cats were harvested soon after death. Whole ears were mounted onto Franz-type diffusion cells with the stratum corneum of the inner pinnae uppermost. A commercial transdermal preparation containing methimazole (0.1 ml/10 mg) was applied to the inner pinnae. At 1, 2, 4, 6, 8, 12, 18, 24 and 30 h, a 200 µl sample of reservoir solution was removed to determine the methimazole concentration by high-performance liquid chromatography. The ears were then dissected, separating the internal pinna from the cartilage and the external pinna, before the methimazole concentration was measured at each site. The thickness of the different regions of the ear was measured on paraffin histology sections. RESULTS: Mean ± SD methimazole concentrations at 30 h for the right and left ear, respectively, were: inner ear, 1.25 ± 0.53 mg/g, 0.39 ± 0.26 mg/g; cartilage, 1.36 ± 0.47 mg/g, 0.33 ± 0.20 mg/g; and outer ear, 1.0 ± 0.32 mg/g, 0.33 ± 0.14 mg/g. There was a difference between the left and right ears (P <0.001). Minimal methimazole concentrations were detected in the receptor fluid. The mean methimazole concentration absorbed by the skin after application of 10 mg was, for the right ear, 3.65 ± 1.27 mg/g and, for the left, 1.08 ± 0.27 mg/g. There was no correlation between methimazole concentrations and thickness of each region of the ear. CONCLUSIONS AND RELEVANCE: Methimazole in a lipophilic vehicle applied to the inner pinna will penetrate to the outer pinna of cats in an in vitro model, which may have safety implications for humans associated with cats treated with transdermal methimazole. Substantial inter-individual variation was found. Further research is required in the area of transdermal penetration of drugs in cats.

Muscular dystrophy with truncated dystrophin in a family of Japanese Spitz dogs.

Muscular dystrophy was diagnosed in seven male Japanese Spitz dogs with clinical signs of slowly progressive exercise intolerance, generalized weakness, myalgia, difficulty chewing and dysphagia. Serum creatine kinase (CK) concentrations were markedly elevated. Histopathology showed degeneration and regeneration of muscle, consistent with a dystrophic phenotype. Immunohistochemical staining for dystrophin and related proteins showed no staining with a monoclonal antibody against the rod domain of dystrophin but near-normal staining with an antibody against the C terminus. Immunoblot analysis in two affected dogs showed a truncated dystrophin protein of approximately 70-80 kDa. The severity of disease showed that this fragment was not large enough to protect from the dystrophic process.

Assessing the severity of canine pancreatitis.

The objective of this study was to determine whether laboratory testing currently available is able to provide prognostic information in canine pancreatitis. A prospective study of dogs with naturally occurring pancreatitis was undertaken. Twenty-two cases with histologically confirmed pancreatic inflammation were included in the study. Each dog had routine haematology parameters, serum biochemistry (including lipase and amylase), serum trypsin-like immunoreactivity and trypsinogen activation peptides (TAP) in urine and plasma measured. Twelve of the dogs were classified as having severe disease. These dogs had statistically significant increases in urinary TAP-creatinine ratio (UTCR) measurement, serum lipase, serum phosphate and serum creatinine concentrations. Additionally dogs with severe pancreatitis had significantly decreased urine specific gravity levels. The most sensitive and specific test to assess the severity of pancreatitis was the measurement of UTCR.

Tetanus in the dog: review and a case-report of concurrent tetanus with hiatal hernia.

: Tetanus with hiatal hernia was diagnosed in a four-month-old female sheepdog pup. The animal was treated with tetanus antitoxin, antibiotics, fluids and intensive nursing care for three weeks and subsequently made a full recovery.

Clinical signs, diagnosis and treatment of three dogs with angiostrongylosis in Ireland.

: Infection with Angiostrongylus vasorum was diagnosed at necropsy on a dog that died from acute pulmonary haemorrhage, and on recovery of L1 larvae by Baermann examination of faeces from two dogs, one of which had abdominal pain and retroperitoneal haemorrhage, while the other had right-sided heart failure due to cor pulmonale. The presenting signs included syncope (one dog), exercise intolerance (two dogs), cough (two dogs), abdominal pain (one dog) and depression (one dog). One-stage prothrombin time and activated partial thromboplastin time were prolonged in two dogs, buccal mucosal bleeding time was prolonged in one dog and globulin was elevated in all three dogs. Two dogs were treated with fenbendazole and recovered.

A novel mutation in CLCN1 associated with feline myotonia congenita.

Myotonia congenita (MC) is a skeletal muscle channelopathy characterized by inability of the muscle to relax following voluntary contraction. Worldwide population prevalence in humans is 1:100,000. Studies in mice, dogs, humans and goats confirmed myotonia associated with functional defects in chloride channels and mutations in a skeletal muscle chloride channel (CLCN1). CLCN1 encodes for the most abundant chloride channel in the skeletal muscle cell membrane. Five random bred cats from Winnipeg, Canada with MC were examined. All cats had a protruding tongue, limited range of jaw motion and drooling with prominent neck and proximal limb musculature. All cats had blepharospasm upon palpebral reflex testing and a short-strided gait. Electromyograms demonstrated myotonic discharges at a mean frequency of 300 Hz resembling the sound of a 'swarm of bees'. Muscle histopathology showed hypertrophy of all fiber types. Direct sequencing of CLCN1 revealed a mutation disrupting a donor splice site downstream of exon 16 in only the affected cats. In vitro translation of the mutated protein predicted a premature truncation and partial lack of the highly conserved CBS1 (cystathionine ß-synthase) domain critical for ion transport activity and one dimerization domain pivotal in channel formation. Genetic screening of the Winnipeg random bred population of the cats' origin identified carriers of the mutation. A genetic test for population screening is now available and carrier cats from the feral population can be identified.