Today we are meeting Atticus, a Maine Coon cat who presented to his vets after a history of ‘grumpiness’. On further examination other problems were identified that culminated in an unexpected diagnosis. Thankfully the treatment for this disease has been going very well. Let’s start from the beginning.

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Meet Atticus

Atticus is a 7-year old male neutered Maine Coon cat. For those that don’t know Maine Coon cats are one of the largest breeds of domestic cats, with strong musculature, weights topping 8kg or more, and a length of almost a metre including the tail. They are also incredibly fluffy! Atticus had been acquired by his current owner after the previous owner, a Maine Coon breeder, had passed away when Atticus was 5 – the new owner didn’t have any previous experience with Maine Coon cats, but learned quickly. 

Atticus lives alone with his owner and is kept indoors, after having been hit by a car when he was a young cat and hurting his hip. He is fully vaccinated and treated regularly for fleas and worms. Aside from the occasional bout of vomiting he had no other medical history, though the new owner did note he occasionally limped on his right hind leg. 

The First Sign of a Problem

Atticus’ owner always found him a friendly cat, so was surprised when he started to get grumpier in his old age. She noted he was less keen on having a fuss, preferred to spend time alone in his bed, and even hissed a few times when she touched his back end. Not wanting to live with a big grumpy cat, she decided to visit her local vets. 

First Consultation

At the vets, the owner explained Atticus’ problems, thinking it was a behavioural issue she might have caused. “Have I not given him enough of my time?” she worried. The vet, however, believed something else was going on. 

On exam, Atticus was bright and generally friendly on first examination. He was around 20% overweight however (the owner did admit to treating him when he was grumpy…). Starting from the head, the vet examined his eyes, ears, mouth, and nose, and found little to concern them. His heart and lungs were normal, and he was well hydrated. However, when the vet ran a hand down Atticus’ back he hissed at them, just like he was doing at home. The vet explained to the owner they thought Atticus was painful. Going very carefully, they gently palpated his spine, which Atticus didn’t mind.

The vet then felt his thighs, and though Atticus kept a close eye on the vet, there was no pain – this palpation revealed a low muscle mass in the thigh region. Finally, the vet attempted to move Atticus’ hips but Atticus tried to swipe again. Deciding it was best not to anger Atticus anymore the vet placed him on the floor to wander round the consult room. They noted he was swaying a lot on his back end and was subtly limping on his right hip. 

Leaving Atticus to explore, the vet explained to the owner that Atticus was probably developing osteoarthritis, also known as degenerative joint disease, particularly in his hips. This would explain why he was grumpy in this area, losing muscle mass and walked abnormally. 

Osteoarthritis

Osteoarthritis (OA) is a degenerative disease of the joints commonly seen in older animals. Over time, the cartilage protecting a joint starts to erode. This leads to the bones rubbing together, which is painful. It leads to inflammation within the joint, the formation of new bone, further rubbing and loss of cartilage, culminating in difficulties using the joint.

OA is cats caused by a variety of factors including genetics, obesity, poor diet, and trauma. In Atticus’ case, his previous injury to his hip when he was young and being overweight were two big factors. Maine Coons are also predisposed to a genetic condition called hip dysplasia, where the hip joint does not form properly – this can also result in OA. Though this was never formally diagnosed in Atticus, it may have been another factor. 

The diagnosis of osteoarthritis requires radiography to view the damage to the joint, CT scans for a 3D image, or even placing a camera into the joint. Blood tests can also be performed to identify any underlying diseases that could lead to inflammation or obesity, such as diabetes mellitus. However, in many cases the symptoms are sufficient for a presumptive diagnosis of arthritis to be made, and treatment to begin – this was the case with Atticus, as his owner declined x-rays. 

Starting Treatment for Atticus

The owner was keen to start treatment for Atticus’ OA straight away. The vet listed various drugs, but advised starting with a non-steroidal anti-inflammatory drug (NSAID), in this case meloxicam. Atticus’ would start this drug orally once a day, and then be rechecked to assess his progress. The vet advised that reducing inflammation may take time so he wouldn’t necessarily be perfectly comfy in a week.

A week later the owner came back with Atticus

She said he seemed to be a little more comfy but she was concerned he had vomited once. Vomiting and diarrhoea are common side effects seen with non-steroidals but can be caused by a variety of other diseases too. On examination, Atticus was in good health but still unhappy having his back end touched. The vet advised to wait a few more days and see if his vomiting settles down. They noted Atticus was quite prone to vomiting anyway, so it may not have been a side effect of his new medication. 

Two weeks since his first appointment Atticus came back again

This time the owner was in a much happier mood – Atticus was almost back to normal! Though he still wasn’t a fan of heavy stroking and still slept a lot, he hadn’t hissed at his owner once. He also hadn’t vomited, so the owner guessed the meloxicam wasn’t a problem after all. After examination, the vet agreed with the owner and found Atticus much more amenable to having his back end touched. There was still some flinching but no more grumpiness. Having seen a big improvement the owner was keen to continue meloxicam long-term – osteoarthritis unfortunately cannot be cured, only managed, so long-term treatment is important to reduce pain and maintain mobility.

Meloxicam is generally a safe drug for long-term use but will put strain on the kidneys and liver in particular – the vet thus advised they perform a blood test on Atticus to check these organs. The blood test came back all normal, and he was given a green light to start long-term meloxicam. 

The Trouble with NSAIDs 

Atticus was managed well with meloxicam and some changes around the house (more on these later) for several months. His owner was thrilled to have the old Atticus back. However, on his next visit to the vets, things had started to change. 

The vet advised they check his liver and kidneys again, to ensure the meloxicam wasn’t causing harm. Though his kidneys were fine, his liver enzymes were slightly elevated – this indicated that Atticus liver was a little inflamed. The vet advise that this was a common finding when NSAIDs are used long-term, but shouldn’t be ignored. Given that the numbers were low and Atticus was pain-free, it would be acceptable to continue his meloxicam, though this may make damage his liver more over time – sometimes in veterinary medicine, we have to weigh up the positives and negatives of using a drug.

The owner, however, was very worried, and asked if there was anything Atticus could have instead. The vet advised Atticus might benefit from Solensia.

A New Alternative to Cat Osteoarthritis 

There is now a relatively new drug that can be prescribed for feline OA. The active ingredient is frunevetmab, a monoclonal antibody. Monoclonal antibodies are antibodies (tiny proteins that bind to specific receptors, normally to help fight infection or disease) that bind to only one receptor. Frunevetmab inhibits the release of nerve growth factor, a chemical that promotes nociception (pain sensation). By inhibiting NGF, frunevetmab reduces pain associated with osteoarthritis.

The drug is given monthly by a vet as an injection under the skin, like a vaccine. It lasts for at least 4 weeks, particularly when given regularly. The main advantage of frunevetmab over other drugs for OA is that it has very few side effects (the most common being pain and inflammation around the site of injection), and there is currently no evidence it puts strain on the liver and kidneys. This makes it very safe for cats with underlying health issues, or with liver or kidney damage, like Atticus. 

Starting Injections

Atticus’ owner was quite keen on the new option so opted to start it straight away. Atticus received his first injection with little fuss. The vet advised Atticus’ owner to continue meloxicam for a little longer so he would have pain relief as it started working it can take a month or so for the full effects to be seen, though many owners report seeing improvements in their cats’ mobility from as early as 14 days. 

Three weeks later the owner rang back elated, claiming Atticus was more mobile than he’d ever been. “Like a miracle,” she exclaimed! The vet was very pleased and met with Atticus again a week later. Atticus certainly seemed like a different cat as he was jumping around the room much more comfortably. Thrilled with the results, the owner was more than happy for long-term injections. She also found it convenient not having to give him daily medication at home anymore. 

Other Management Approaches

Throughout Atticus’ treatment for osteoarthritis the vet advised a number of other important steps to take to manage the condition – pain relief was only one component.

At home, the owner was encouraged to provide many soft beds and blankets for Atticus to lie on – no more hard floors that strain joints. She also started feeding him on the floor (previously she fed him on the countertop) so he didn’t have to jump; and purchased a litter tray with a low wall, again minimising jumping. 

It was also critical Atticus lost weight. Obesity is a big factor in the development of osteoarthritis, both for the physical weight on the joints, as well as the promotion of inflammation within the body. His owner cut down on treats dramatically, and even started weighing out his food. Progress was slow but steady, and by the time he started Solensia, he wasn’t far from his target weight. Treating pain will encourage a cat to become more mobile, which will increase the weight loss too. 

The vet also discussed a few other therapies that might help Atticus in future. These include gentle manipulation and massaging of the joints, laser therapy, physiotherapy, hydrotherapy (Atticus hates water so this might not be for him!), and even acupuncture. It was also discussed that though the medication is currently working very well for Atticus’ OA, over time his joints will degrade further, and the owner may have to consider reintroducing meloxicam or other drugs again. Ultimately, Atticus’ OA can never be cured, and it may progress to the point where he is too painful and it would be unfair to continue. But for now, Atticus is happier than ever, healthier than he was before, and doing incredibly well on his treatment. 

Further Reading