What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Norwegian Forest Cats can develop hypertrophic cardiomyopathy (HCM), glycogen storage disease type IV (GSD IV), and pyruvate kinase (PK) deficiency. These are different conditions: HCM affects the heart, GSD IV is an inherited metabolic disorder, and PK deficiency can cause anemia. Their inclusion in breed-health resources does not mean every Norwegian Forest Cat will develop them, and the available sources do not establish reliable breed-wide prevalence rates.
At a glance: the three conditions
| Condition | What it affects | How it is evaluated |
|---|---|---|
| Hypertrophic cardiomyopathy (HCM) | Heart muscle | Veterinary assessment and echocardiography (heart ultrasound) |
| Glycogen storage disease type IV (GSD IV) | Glycogen metabolism, muscles, and other organs | DNA test for the Norwegian Forest Cat variant |
| Pyruvate kinase deficiency | Red blood cells; can lead to hemolytic anemia | Veterinary assessment and DNA testing for the variant |
The evaluation methods answer different questions. Echocardiography looks for changes in heart structure, while DNA tests identify a particular inherited variant; a genetic result does not replace a veterinarian’s assessment of a cat with symptoms.
As an Amazon Associate I earn from qualifying purchases.
Hypertrophic cardiomyopathy (HCM)
HCM is abnormal thickening of the heart muscle that can interfere with how the heart works. A Norwegian Forest Cat breed-health document describes possible complications including heart failure, fluid in the lungs, blood clots, and sudden death. HCM also occurs in cats generally; the available sources do not show how prevalent it is across the Norwegian Forest Cat population.
Signs and diagnosis
Possible signs include lethargy, reduced appetite, rapid or difficult breathing, and, in some cases, hind-limb paralysis associated with a blood clot. These signs are not specific to HCM. A veterinarian may hear a heart murmur during an exam, but not hearing one does not rule the condition out.
#1 Best Overall
- Dog multivitamins chewable for skin & coat : Dog multivitamin is rich in Omega-3 fatty acids and vitamin E,which can relieve skin allergies,dryness,itching and other problems.Multivitamin for dogs nourishes skin follicles.Long-term consumption of dog vitamins multivitamin can make dog hair stronger and smoother,and reduce coat loss.The COQ10 in dog multivitamin chewable can resist oxidation and delay cell aging.Dogs with skin injuries can eat dog vitamins and supplements to promote wound healing
- Dog multivitamin relieves joint inflammation: Dog vitamins for hip and joint can supplement high-quality MSM, glucosamine, and chondroitin sulfate to promote cartilage development and repair. Long-term consumption of dog multivitamins chewable can enhance the elasticity and toughness of joint cartilage, improve joint flexibility, and move more freely. Dog multivitamin chews can reduce joint friction and relieve joint pain. Dog vitamins and supplements can prevent and improve dog joint problems
- Dog multivitamin chews are good for the gut: Vet-endorsed formula dog vitamins and supplements made from natural ingredients.Dog vitamins multivitamin chewables contain a rich blend of probiotics to support intestinal and digestive health.Dog vitamins for small dogs can regulate the balance of intestinal flora,help calcium absorption,and promote bone development.Dog multivitamins chewables improve energy metabolism,converting food into energy, making dogs more energetic in their daily activities
- Dog multivitamin chews protect overall health:Senior dog vitamins and supplements help improve blood circulation and prevent cardiovascular disease.Dog multivitamins chewable support normal liver function,promote liver detoxification,and improve negative mood.For dog with heart problems and older dog,taking dog vitamins and supplements in moderation is an auxiliary health care measure.Dog vitamins multivitamin helps enhance white blood cell activity,improve immunity,prevent infection and disease
- Dog multivitamins chewable promote brain development: The DHA in krill oil in multivitamin for dogs is an important component of the brain and retina. Dog vitamins and supplements can improve dog cognitive ability. When training puppies to learn basic commands, puppies who are properly supplemented with dog vitamins multivitamin will behave more intelligently and improve memory.Dog supplements & vitamins can prevent and relieve eye problems such as dry eyes and tear stains, and keep eyes healthy
The breed-health document identifies echocardiography, or ultrasound of the heart, as the most reliable method for diagnosing HCM. If you are concerned about your cat’s heart, ask a veterinarian whether an echocardiogram is appropriate.
Glycogen storage disease type IV (GSD IV)
GSD IV is an inherited autosomal recessive disorder caused by a defect affecting glycogen branching enzyme. Abnormal glycogen can accumulate in cells and contribute to progressive organ dysfunction. UC Davis Veterinary Genetics Laboratory reports that many affected kittens die at or soon after birth. Rare survivors who initially appear normal may develop persistent fever and muscle tremors at around five months, followed by muscle wasting and progressive disease.
Rank #2
- 8-in-1 Formula - Zesty Paws Multifunctional Bites are functional supplement chews with premium ingredients that support physical performance, antioxidants, hip & joint, heart, immune, skin, liver, & gut health for dogs of all ages, breeds, and sizes.
- Skin Health & Antioxidants – For animals with sensitive skin, this formula contains Cod Liver Fish Oil and Vitamin E to help maintain normal moisture and CoQ10 to help reduce oxidative stress.
- Hip, Joint & Performance Support - Each dog chew features OptiMSM, a premium form of MSM for muscular support, which works synergistically with the Glucosamine HCl and Chondroitin Sulfate in these chews for hip and joint support plus Cod Liver Oil and B-Complex Vitamins support normal physical performance.
- Gut Health & Probiotics - These chews also contain a six-strain Gut Health Blend (500 million cfu per chew) and a Digestive Health Blend to promote gut flora while supporting normal bowel function for dogs.
- Heart, Liver & Immune Health - Multifunctional Bites feature powerful antioxidants, premium CoQ10, Cod Liver Oil and Vitamins A, C, & E to promote healthy cardiovascular function, support liver health and enhance immune response.
Understanding GSD IV DNA results
The UC Davis test interprets results for the specific Norwegian Forest Cat mutation it tests:
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →- N/N: No copy of the tested variant detected.
- N/GSD: Carrier of one copy. UC Davis describes carriers as not having the disease, but they can pass the variant to offspring.
- GSD/GSD: Two copies of the tested variant; the cat is genetically affected.
When both parents are carriers, each kitten conception has an expected 25% chance of producing an affected kitten under the autosomal recessive inheritance model. This is a probability for that specific mating, not a measure of how common GSD IV is in the breed. The 2007 study record describes a complex GBE1 rearrangement associated with perinatal hypoglycemic collapse and later juvenile neuromuscular degeneration in Norwegian Forest Cats; it does not establish current breed-wide prevalence.
Rank #3
- COMPLETE 26-IN-1 DAILY WELLNESS FORMULA: Our advanced multivitamin for dogs is formulated to help support 26 vital nutritional areas as part of a daily routine. With essential vitamins A, C, D3, and E, these gummies help support the immune system and contribute to overall heart and brain health for dogs of all sizes.
- ADVANCED HIP AND JOINT MOBILITY SUPPORT: Formulated with Glucosamine HCl, Chondroitin, and MSM to help support cartilage health, joint flexibility, and everyday mobility — making them a great daily supplement for large breed dogs and active senior dogs.
- SKIN & COAT SUPPORT: Packed with Norwegian Salmon Oil and Biotin, our dog multivitamin helps nourish skin from within and supports a soft, glossy coat. Omega 3 fatty acids contribute to healthy skin and coat as part of a complete daily nutritional routine.
- PROBIOTICS & DIGESTIVE SUPPORT: Features a Six-Probiotic Blend (500 Million CFU) and Digestive Enzymes to help support gut health, smooth digestion, and nutrient absorption. Cranberry Powder is included as part of this comprehensive daily wellness formula.
- UNBEATABLE VALUE 250 COUNT JAR: Our 250-count jar provides lasting daily support in a delicious chicken flavor. Made in the USA in a GMP-certified facility, our soft chews are grain-free and suitable for puppies, adult, and senior dogs alike.
Pyruvate kinase (PK) deficiency
PK deficiency is an inherited lack of adequate pyruvate kinase activity in red blood cells. The resulting premature breakdown of red blood cells can cause hemolytic anemia. A New Zealand Cat Fancy policy describes age of onset and severity as variable, and notes that a DNA test is available.
Possible signs and testing
Signs listed in Norwegian Forest Cat health material include fatigue or lethargy, pale gums or other mucous membranes, poor appetite, weight loss, poor coat condition, and increased heart rate or breathing. These signs can have other causes, so they require veterinary evaluation rather than a home diagnosis. DNA testing can identify the tested variant and may inform breeding decisions; it does not establish the cause of symptoms by itself.
Rank #4
- Joint Health Supplement for Dogs: Cosequin is the #1 vet recommended retail joint health supplement brand, supporting joint health in dogs for over 25 years
- Contains Glucosamine for Dogs: Cosequin contains glucosamine hydrochloride (FCHG49) and sodium chondroitin sulfate (TRH122), plus methylsulfonylmethane (MSM). This unique combination of ingredients supports healthy joints
- For Any Breed or Size: Whether you have a young or senior dog, a small or large breed, Cosequin helps support their joint health
- Tasty Chews for Daily Use: Cosequin comes in a tasty chewable tablet, making daily administration easy and convenient
- Exceptional Quality: Cosequin is backed by science, undergoing thorough quality inspections to ensure your dog receives a safe, high-quality product. It is manufactured in the United States with globally sourced ingredients
What screening may be recommended?
Screening schedules are not necessarily the same across registries or countries. A Felis Belgica screening document lists echocardiography for HCM and DNA tests for PK deficiency and GSD IV, with timing and repeat intervals specific to its program. Treat that schedule as an example of one published program, not a universal veterinary standard. Ask your veterinarian which screening is suitable for your individual cat and local guidance.
If you are choosing a kitten, ask the breeder what screening has been done and request the relevant documentation, including the laboratory and the specific test. For genetic results, confirm that the report concerns the Norwegian Forest Cat variant in question; a test result only addresses the variant it tested.
Best Value
- Itch & Allergy Relief with Omega-3 for Dogs - with 500mg of Omega (EPA+DHA) per serving, our chewable supplement helps with hot spots, dry itchy skin, ease itching, irritated skin, stops shedding.
- Skin & Coat + Hip & Joint Supplement Combined - Omega 3 is a vital element to keep your pet active, support healthy hip and joints, brain, heart, immune health. Can be served with regular pet food.
- Bark&Spark Commitment - we are keen to give best to our furry customers and we take NO compromise when it comes to product quality. Our omega 3 bites are made in the USA, with human grade ingredients.
- Up to 3 Month Supply - with 180 salmon oil treats per jar you keep your pet healthy while not spending a fortune on overpriced supplements. Best value.
- Is Your Dog a Picky Eater? We stick to simple formulas rich in natural flavors, that could tempt a fussy eater. No hassle with pills, powder, tablets or capsules.
When to seek veterinary care
Contact a veterinarian promptly for breathing difficulty, collapse, marked lethargy, pale gums, weakness, or another sudden or severe change. These signs can indicate urgent illness, but they do not identify which condition is responsible. Do not wait for a scheduled screening appointment when a cat is acutely unwell.
Quick Recap
Sources
- UC Davis Veterinary Genetics Laboratory: Glycogen Storage Disease type IV (GSD IV) in Norwegian Forest Cats
- UC Davis Veterinary Genetics Laboratory: Norwegian Forest Cat genetic testing information
- Norwegian Forest Cat breed-health document (2025), hosted by NRR
- New Zealand Cat Fancy: Norwegian Forest Cat Health & Conformation Policy, approved 2019 and effective 2020
- Felis Belgica: Norwegian Forest Cat screening document
- Fyfe et al., 2007: PubMed record on a GBE1 rearrangement associated with GSD IV
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
