Investigation of the allele frequency of the G>A intron 10 ADAMTS17 mutation causing primary lens luxation in the Portuguese Podengo breed.

OBJECTIVE: To establish the allele frequency of the PLL-causing G>A intron 10 ADAMTS17 mutation in the Portuguese Podengo population in the UK and investigate a possible correlation between the mutation and short stature. METHODS: Two groups of dogs (Group 1 and Group 2) were recruited for the purpose of the study. Group 1 (n = 40) consisted of dogs which were genotyped only and Group 2 (n = 42) consisted of dogs which were genotyped, underwent a full ophthalmological examination and also had their height measured at the withers. RESULTS: In Group 1, genotyping for the ADAMTS17:c.1473+1G>A mutation confirmed 1/40 homozygous for the mutated allele (-/-), 7/40 heterozygous for the mutated allele (+/-), and 32/40 homozygous for the wild-type allele (+/+) dogs. In Group 2, genotyping of the dogs confirmed 6/42 heterozygous for the mutated allele (+/-) and homozygous for the wild-type allele (+/+) dogs. In total, 1/82 (1.2%) dogs were confirmed to be homozygous for the mutated allele, 13/82 (15.8%) heterozygous for the mutated allele and 68/82 (83%) homozygous for the wild-type allele. The frequency of the mutated allele across both groups was calculated as 0.09. A statistically significant correlation between the mutation and short stature could not be established (p = .590). CONCLUSIONS: The frequency of the mutation calculated in this study (0.09) is high. Genetic testing should be considered for each dog prior to breeding with a view of selective breeding.

Comparison of the prevalence of Domestic Cat Hepadnavirus in a population of cats with uveitis and in a healthy blood donor cat population in the United Kingdom.

OBJECTIVE: Domestic Cat Hepadnavirus (DCH) is a novel virus recently identified in the domestic cat. Currently, little is known regarding its clinical significance. The hepadnaviridae family includes the Hepatitis B Virus (HBV). Co-infection of HBV and Hepatitis C in humans increases the risk of uveitis. We aimed to determine whether DCH is present in the United Kingdom (UK) and whether DCH warrants investigation as a potential cause of uveitis in cats. PROCEDURES: Clinical records from the Royal Veterinary College (RVC) and the Animal Health Trust (AHT) were reviewed for feline cases diagnosed with endogenous uveitis. A healthy control group was identified from cats presented to the RVC as blood donors. DNA was extracted from stored blood samples using commercially available kits. Polymerase chain reaction assays were performed to confirm the presence of feline DNA and to detect the presence of DCH DNA using previously described protocols. RESULTS: Blood samples were available from 65 cats with endogenous uveitis and 43 healthy control cats. Two blood samples from cats with endogenous uveitis tested positive for the presence of DCH DNA. DCH DNA was not detected in the control group. There was no statistically significant difference between the prevalence of DCH between the groups. CONCLUSIONS: Domestic Cat Hepadnavirus is present in the UK. This study failed to demonstrate a conclusive link between DCH and uveitis in cats, although further studies to investigate an association with other feline diseases are warranted.

A multicenter retrospective study into endogenous causes of uveitis in cats in the United Kingdom: Ninety two cases.

PURPOSE: The purpose of this study was to investigate the most common causes of endogenous feline uveitis in a UK referral population and to investigate associations based on signalment. METHODS: Retrospective multicenter cross-sectional study from 2010 to 2019 including cats presented to the Animal Health Trust and the Royal Veterinary College with clinical signs consistent with uveitis. Cats were included in analyzes if they had a full physical examination including an ophthalmic examination, complete blood count, serum biochemistry, and infectious disease testing for at least two diseases unless the diagnosis was found on clinical examination (eg, neoplasia). RESULTS: A total of 92 cats were included in the study. The majority of cats presenting with uveitis were male (66.3%). The most common causes of endogenous uveitis were idiopathic uveitis (42/92 45.7%), feline infectious peritonitis (FIP) 15/92 16.3%), and lymphoma (10/92 10.9%). Fisher's exact test showed differences in breed across diagnosis groups (p = .002) with purebred cats being overrepresented in the lymphoma and FIP groups. Kruskal-Wallis test showed differences in median age across diagnosis groups (p < .001) with cats in the FIP group having the youngest age (median 1.4 years, interquartile range (IQR) 0.4-1.8 years) and cats in the neoplasia (primary or paraneoplastic) group having the oldest age (median 12.8 IQR 10.8-13.8). Idiopathic uveitis was unilateral in 56.1% of cases, and infectious causes were unilateral in 47.8% of cases. CONCLUSIONS: The most common cause of endogenous uveitis in a population of cats in the UK was idiopathic uveitis, followed by FIP and lymphoma.

Outcome of phacoemulsification in 71 cats: A multicenter retrospective study (2006-2017).

PURPOSE: To assess outcome of phacoemulsification in cats. METHODS: Records of 71 cats (82 eyes) from five referral centers were reviewed. Groups were divided by cause of cataract (congenital/juvenile [n = 32], traumatic [n = 33], and secondary to uveitis [n = 6]), and group comparisons were performed for the most common complications: postoperative ocular hypertension (POH), uveitis, corneal ulceration, synechia/dyscoria, and posterior capsular opacity (PCO) in three different time periods: immediately postoperatively, at 1-90 days, and at >90 days. RESULTS: Median follow-up was 198 days (interquartile range 64-518 days). The overall visual success rate of the cats with a 12-month follow-up was 92.6% (25/27 eyes). POH occurred in 35/82 (42.6%) eyes. Immediately postoperatively, uveitis was the most common complication in 28/82 eyes (34.1%) followed by corneal ulceration in 22/82 eyes (26.8%). At 1-90 days, uveitis in 41/81 eyes (50.6%) remained the most common complication, followed by synechia/dyscoria in 21/81 eyes (25.9%), corneal ulceration in 16/81 eyes (19.7%), and PCO in 15/81 eyes (18.5%). At >90 days, PCO in 17/47 eyes (36.1%), followed by synechia/dyscoria in 16/47 eyes (34%), was the most common complications. The number of eyes with synechia/dyscoria in the trauma group was higher (13/33 [39.3%]) than in the congenital/juvenile group (5/31 [16.1%]) at 1-90 days (P = .039). No statistical difference was found for the other group comparisons. Three eyes in total were enucleated owing to endophthalmitis, post-traumatic ocular sarcoma, and secondary glaucoma. CONCLUSION: Uveitis in the short-term and PCO and synechia/dyscoria in the long-term were the most common complications following phacoemulsification in cats.

Glaucoma-causing ADAMTS17 mutations are also reproducibly associated with height in two domestic dog breeds: selection for short stature may have contributed to increased prevalence of glaucoma.

BACKGROUND: In humans, ADAMTS17 mutations are known to cause Weill-Marchesani-like syndrome, which is characterised by lenticular myopia, ectopia lentis, glaucoma, spherophakia, and short stature. Breed-specific homozygous mutations in ADAMTS17 are associated with primary open angle glaucoma (POAG) in several dog breeds, including the Petit Basset Griffon Vendeen (PBGV) and Shar Pei (SP). We hypothesised that these mutations are associated with short stature in these breeds. METHODS: Two hundred thirty-three PBGV and 66 SP were genotyped for their breed-specific ADAMTS17 mutations. The height of each dog was measured at the withers. We used linear (per allele) regression to assess the association between ADAMTS17 mutations and height as a continuous variable, and linear regression and likelihood ratio tests to assess the shape of the association by comparing a general model with a linear (per allele) model. RESULTS: The adjusted mean heights of affected, carrier, and clear PBGV were 33.49 cm (n = 21, 95% CI 32.78-34.19 cm), 34.88 cm (n = 85, 95% CI 34.53-35.25 cm), and 34.92 cm (n = 121, 95% CI 34.62-35.21 cm), respectively. The mean heights of affected, carrier, and clear SP were 43.96 cm (n = 9, 95% CI 41.88-46.03 cm), 47.56 cm (n = 28, 95% CI 45.50-48.63 cm), and 48.95 cm (n = 23, 95% CI 47.80-50.11 cm), respectively. There was a significant difference between the height of affected and clear animals in the PBGV (P = 0.001) and the SP (P = < 0.0001). CONCLUSIONS: ADAMTS17 POAG mutations are significantly associated with height in these breeds.

Rhomboid blepharoplasty and cryotherapy for the treatment of a squamous cell carcinoma on the lower eyelid in a horse.

A rhomboid blepharoplasty can be used to achieve functional and cosmetic eyelid reconstruction at the medial canthus in the horse. Combination of a rhomboid blepharoplasty with cryotherapy is a treatment option for eyelid ocular squamous cell carcinomas.

Pax6 exerts regional control of cortical progenitor proliferation via direct repression of Cdk6 and hypophosphorylation of pRb.

The mechanisms by which early spatiotemporal expression patterns of transcription factors such as Pax6 regulate cortical progenitors in a region-specific manner are poorly understood. Pax6 is expressed in a gradient across the developing cortex and is essential for normal corticogenesis. We found that constitutive or conditional loss of Pax6 increases cortical progenitor proliferation by amounts that vary regionally with normal Pax6 levels. We compared the gene expression profiles of equivalent Pax6-expressing progenitors isolated from Pax6⁺/⁺ and Pax6⁻/⁻ cortices and identified many negatively regulated cell-cycle genes, including Cyclins and Cdks. Biochemical assays indicated that Pax6 directly represses Cdk6 expression. Cyclin/Cdk repression inhibits retinoblastoma protein (pRb) phosphorylation, thereby limiting the transcription of genes that directly promote the mechanics of the cell cycle, and we found that Pax6 inhibits pRb phosphorylation and represses genes involved in DNA replication. Our results indicate that Pax6's modulation of cortical progenitor cell cycles is regional and direct.